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i
good afternoon welcome to my monday stream for june fourteenth
its rainy day here in toronto and i'm hoping to make some more 
progress on the arm
naked modules that is these modules with the with no pink front panel 
so that i can put the the custom panels on there
i have a little slide show of
the custom panels which are now basically ready to go so its just a 
matter of trying hello
pitch its just a matter of getting some modules with don't have panels 
cause i'm not going to make a call assembled module for every panel 
when i don't know follow them or solve some of them are are a lot 
better than others so i'm gonna make some modules that don't have
panels and then have those ready and then as people want to buy 
accustomed panel module i'll put the appropriate panel on it and to
it'll be ready to go and i have a slideshow which i think i'll show 
later of what the the finished panels look like they many of them have 
come out pretty well some have not come out really well at all but i 
don't think i can predict which ones people will or will not want so 
i'm just going to
post photos of all of them and let people buy whichever ones they want
now since last week owing to today i'm also planning to do a bit of 
chatter about an impedance and power and voltage and current and so on 
because i had a request for that and
since last week i have gone and bought a bunch more parts for the 
things that i was running low of and so i think i can now
finish some of these these checklists and to get all of the parts for 
the current batch of naked modules into into their bins so the first 
thing i'm looking at here is the leapfrog board three
that'll be in these these champions
and some of the ones i replenished were these trimmer pots
i
and i am going to be doing fixed resistors
so starting with the one case

huh
there are a whole lot of fixed resistors and basically all analog 
circuits
and that's partly because they performer of fairly useful and simple 
function
i was thinking earlier about how
how do we explain impedance to someone who really doesn't know
and one of my friends on twitter
had a bunch of questions about this sort of thing because she was 
setting up a year
a solar power system i think in the arizona desert
and so its like well okay so my batteries are charged this many 
empowers and
but then the consumption of power isn't in terms of amps its in terms 
of watts and how do we convert and why don't we just standardize a 
single voltage and so forth and so on
and got quite frustrated because everyone who tried to answer her 
questions including myself
i tried to do so by saying well its a lot like water
no no how can you explain this without using water as an analogy the 
fact is water is a really good analogy i mean long before people had 
any really clear idea of what electricity was
they had the idea that it behaved like a fluid because it does and in 
sort of nineteenth century science there were several of these i think 
they were called imponderable fluids or something like that that the 
idea that there were things in the world that function like like liquor
woods or gases even if
their exact nature is unknown
and electricity is one of those things
it its a little weird because you can't put it in a container unless 
you can but you know it flows through solid objects and it doesn't flow 
usually through empty space but it does behave like a fluid and in 
particular if you've got something in this case a wire that you put 
electricity
at one end then you push some electricity through and the same amount 
comes out at the other end
ah it really functions as if there is some sort of special liquid or 
fluid of some kind that is is flowing through the solid objects and 
that's unsurprising as the
as our knowledge of physics got better we figured out that okay 
electricity is actually
a collection of electrons little tiny objects much tiny particles much 
like other
other fluids
and they take up space and they bump against each other and so they 
behave very much like something like water which is also a collection of
tiny particles
i
but electricity is also different in other ways in particular that it 
doesn't seem to have much or maybe not even any weight
and there's this weird thing of it flows through some solid materials 
and it doesn't flow through other materials that would seem to work
be more assertive in substantial so
what's really going on
i
so that's why electricity is like water but i was also trying to think 
of
are there other ways to understand it
that that actually dontcha
that actually don't involve an analogy to water
and i think that one that does actually make a lot of sense to me at 
least as far as talking about impedance
is to say that's the way that electricity works or at least the way 
that impedance works with respect to impedance
its a lot like riding a bike
its been a long time actually since i rode a bike but i used to used 
to ride around at a mountain bike and it had multiple gears right
so if i'm going up a hill or whatever
and
as i press on the pedals with my with my feet there's a lot of
i want to say resistance but i'm going to try to avoid using that term 
except for the electrical concept because there's a lot of pressure 
that i'm having to apply to the pedals
i i'm applying a lot of torque in mechanical terms
and moving my moving my feet at a relatively low speed very few revs 
not many rotations per minute on the pedals there whereas then if i go 
over the hill and i'm
on the downslope or or better yet going along a straightaway where its 
paved its smooth and there's not a lot of fun
effort i have to put into it to make the bike go faster i'm going to 
switch into a higher gear but you know right at the start before i 
before i change gears
i'm going to i'm going to be spinning my my feet really fast and not 
getting much much pressure so there's low torque and high reps its the 
opposite of the the situation going up the hill
but i
there are limits to to how my body can actually work right there's only 
so much pressure i can put on the pedals and also there's only so fast 
i can i can spin my legs
so if i were using a single speed bike and trying to go up and down 
hills
it wouldn't work very well because i'd be in that situation most of the 
time where either i'm really struggling to put enough pressure on the 
pedals to move at all or else i'm just spinning my feet and wasting my
wasting my
effort that way
and so of course what happens is the bike has at least if its a 
mountain bike designed for this kind of riding where there is a big 
change in the the gradient and so on and its gotten multiple gears so 
i can when i'm on the straightaway i can switch to a higher gear and 
that'll what it'll do is it
it'll change the ratio between the my feet and the pavement
okay what am i looking for here at five point six
so that i will end up getting feeling more pressure on the pedals and 
moving more slowly because there's fewer revs on the pedals compared to 
the many reps on the
on the wheels and then when i'm going up the hill i switch to a lower 
gear
and
where where i i can actually spend my legs faster and get more revs for 
the same number on the pavement and then i get less pressure and then i 
can i'm still able to make progress
so what we've established there is that there's there there are two 
ways that you can be putting energy into moving the bike you can be 
doing it by
by putting a lot of torque on the pedals or you can do it by
by moving your feet fast
and the and there's this tradeoff right that the amount of energy 
you're actually spending
in fact its exactly related to the ratio the the product of those two 
you could double the the the torque at the same speed or you could 
double the speed at the same torque either way you'd be putting in 
twice as much energy
but something else we can get from this is that a power source like my 
body in that case
it has a preferred way of doing this right i can't just spin my legs 
really fast at a low rate and low pressure
or
increase the pressure arbitrarily high
and have it work i have sort of a preferred level of how fast i want to 
be moving my legs and i'm guilt going to get the best results out of 
the bike if i can keep the gear set to a gear which will change 
depending on circumstances that keeps me out that preferred level of of 
speed and pressure
now
what does all this have to do with with electricity well with 
electricity you've got some kind of a force
technically its e m f the electromotive force
which which press it which is pressing the electric fluid through 
whatever its its passing through
i understand at this point we don't even need to know about electrons 
and so on because the people who developed this theory didn't okay they 
just knew that there was something that behaved like a fluid
i
it is but you but like have like other kinds of fluids it had a 
pressure so you've got some kind of pressure on the electric fluid now 
that doesn't mean its moving just like on the bike if if i'm stuck in 
the mud i can be pressing very hard on the pedals and not actually 
moving
and there's not necessarily any emotion but you can have pressure 
without motion
but then if you do have motion you can say well how how much is it how 
much fluid is moving how how many revs have we got on the pedals and 
that's correct okay the the pressure is voltage
i
and so the the the actual emotion is current
but then you can also say well we have this sort of preferred ratio 
between them we say well there's
what there's there's some thing that that is consuming this flow of 
electricity or whatever
is this six point eight
yeah
i
if i double the the pressure i can expect to get twice as much flow if 
i know i'm getting twice as much flow that can probably meant that i 
doubled the pressure but there's some kind of semi fixed ratio which is 
kind of like what gear my in that is resistance or impedance now these 
resistors here
their their function is to provide a fixed ratio between current and 
voltage
i can be pretty sure that whatever amount of voltage electric pressure 
i apply to these and amount of electricity will flow through it that is 
in proportion to that
and the the constant of proportionality if you will the year the ratio 
between them just how much voltage do i need to get a certain current 
that's called the resistance
and it happens to be pretty convenient to build resistors with the wide 
range of different resistances
so we've developed electric technology that makes use of that
i
but it doesn't have to be a resistor okay there any time you're using
and a flow of electricity
you can say what is the ratio of voltage current here
and usually if its not really a resistance i mean if if
if its some other kind of thing it'll be called it'll often be called 
impedance instead of resistance now i don't have any seven point five 
kilometers sisters here and i think i should so i may have to poke 
around here and figure out where i left them
i
i may have just like stuck them in the wrong being here
one example is a transmission line
if you've got like a a coaxial cable
as you put it this is especially true when its not directorate what if 
its like a c if you as you start to put an occurrence into that you 
start applying pressure to a voltage to the end of the cable then the 
electricity will start to flow but as it flows it creates a magnetic 
field and it also charges up the
the capacitance that exists between the center conductor and the
and the shield in that
collects cable and so that as its charging that up that causes a
a vacuum fo a corresponding
voltage that presses back so even though there's not really anything 
being consumed it functions when you're when you're start trying to 
send electricity through your co x cable its it functions as if 
there's a resistance
i
then if you shut it off or if it changes direction
i
either
the the existing flow kind of has something that functions like 
momentum the point is it gets pretty complicated and that cable just by 
the way the cable is constructed its a it has a preferred ratio of 
voltage occurred
you can't put just whatever voltage on the cable you want it has to 
line up with the amount of current that's flowing in
and so what happens is even though there's nothing in the cable that 
consumes the electricity
it it still has a preferred ratio of voltage and current
and if if you
try to feed in voltage and current in a ratio that doesn't match that 
its not really going to work very well
and this is something that comes up specifically when you're dealing 
with transmission lines
coex cables that sort of thing at higher frequencies
i
and what it means is that if you if you try to send a signal that 
doesn't work at an impedance that doesn't work down the cable it'll 
like get to the end of the cable and bounce back or instead of going 
through the game to get to where you expected it to go that sort of 
thing
i
i'm really not sure about where those seven and a half k resistors 
could have gone
i know i had some here are some seventy five
and here's more seventy fives and here more seventy fives
it seems like a possibility that i could have put the seven point farms 
in with the seventy five spanish say
but that don't seem to be in there
hello surplus g
we're supposed
now the radio people care a lot about this impedance matching business
i
because they they don't want to have it is especially on a transmitter 
you want to put your
you want to put your signal into the cable at one end and have it get 
to the antenna at the other end and not have a lot of bounce back into 
the amplifier work because damage
so
they make they make a fairly big effort to make sure that the 
transmitter and the transmission line and the antenna at the end of it 
should all have a mat impedance that matches
meaning that all of those things are set up to expect the same ratio of 
voltage and current
its similar to with the bike saying well i want to be in the right 
gear i want to be running my bike in the gear that is comfortable for 
me to walk to peddle it
and what what year that is will actually change because the bike is a 
sort of a transformer it changes the impedance it it sets the ratio of 
impedance from one side to the other from from the pedals to the wheels
what the transformation ratio is is going to be different because 
different parts of the world wherever i'm riding are going to have 
different characteristic impedances the straightaway effectively has a 
low impedance there's very little pressure applied to the
there's very little torque needed to achieve a relatively high speed
whereas the hill has a high impedance it takes a lot of torque
to spin the wheels even a little bit

now just like the bike transforms impedance
i
we can build different electronic devices that that also transform the 
impedance so if you've got a device that has a low impedance it 
requires a high current at a relatively low voltage
then you can build a a transformer that will take maybe you have some 
source that for whatever reason wants to create a lot of voltage for a 
low current and
it'll sort of rearrange things that gear it down
as the bike would
i really don't know where my seven point five k resistors are
but i don't want to be poking around here searching for them mostly in 
places that would have to be off camera
so i think i'm just going to circle that on the list and keep going
i
if i'm really lucky maybe they'll turn up in one of these other bins i 
look at
get onto the twenty two k
now there are different advantages and disadvantages to voltage and 
current
if you've got a current flowing through a wire the amount of loss that 
you have to deal with
he is basically proportional to that kurt
so if you're transmitting electricity over a long distance especially
you would really like it to be done at a high impedance you want to 
have a lot of voltage and low current so that is why your long distance 
electricity lines
our high voltage lines ok you don't want to have to spend a lot of 
money on the copper wires that you string between the poles you want 
those wires to be relatively thin
and so in order to get a lot of power through there you trade off in 
the direction of more voltage less courage
on the other hand a lot of the things that you would want to do with 
electricity like especially if you're dealing with an electric motor 
for instance where there's a coil of wire or aura
or a light bulb that kind of thing
those those really work best at low voltages so what the electric 
company does is they they run their high voltage lines
to your local substation and then that there are transformers there 
that transform it down to higher current lower voltage
and then often
often when you actually use the electricity might take your
one twenty two twenty volt to house wiring which again is a relatively 
high voltage because you want to minimize transmission losses in the 
wiring
and then there are you transform it down and maybe process it in other 
ways in the power supply to get it down to like twelve volts for a 
synthesizer or five volts or even three point three volts for a 
different computer kinds of things that require that lower voltage
and those those operations are transforming it by lowering the voltage 
increasing the current
effectively changing it to a lower impedance
if your power supplies an efficient one you don't lose much power in 
that
you're just changing its changing the form much like the
the bike
switch gears my my feet up or down to better match
the demands of the the local geography

and as for specific voltages like
my friend with the solar system wanted to know why why is this system 
designed to run at twenty forty eight volts
well the main reason is because
that's what the old telephone batteries were so battery technology 
especially when you've got big banks of batteries
a lot of the equipment for dealing with that tends to be designed for a 
forty eight four system
and
what am i looking at next one forty
so that's convenient
and there again the things you would want to do with the electricity 
you usually wanted a lower voltage but on the other hand are higher 
voltage is more convenient for transmission
so there'll be a trade off at some sort of medium size voltage that 
seems like its about right
and forty eight faults in particular is about the highest voltage you 
can get where a shock is very unlikely to be fatal
if you've got a shock with forty eight vol two volts you might feel it 
but its very unlikely to kill you any higher and that becomes a real 
possibility so a whole lot of safety regulations basically start 
kicking in at about fifty volts
forty eight if it
lightning is a very much higher voltage but forty eight volts is 
convenient because both because of historical reasons its been used 
for a long time and the reason its been used for a long time is its 
about as high as you can go and not have to think too hard about safety

i
i am sort of planning a weblog article on voltages and in particular why
why do we use the voltages we do because that would probably be a
an interesting topic
twelve volt is popular you see that like in car batteries a lot
and of course iraq synthesizers which use plus and minus twelve folds
i
i think the the sort of classic lead a lead acid batteries
have a kind of a natural love
natural voltage per cell of
i guess its to valencia for those but then your classic dry cell 
batteries
are about one point five volts so its kind of nice to use a multiple 
of six because then it kinda
it can be a round number of battery cells for either
and so six folds twelve or twenty four or forty eight
people like doubling with the units
at least in the states where they have all these american customary 
units that are like
pints and quarts and gallons the that i'll go by doubling
so you end up with six multiplied by a power of two is feels like a 
nice convenience
convenience of voltage

but then five volts is for many many years that was the standard for 
digital logic but digital logic has been moving down towards lower and 
lower voltages
my usb host here this microcontroller chip on it it takes a three point 
three volt input but the the actual core is i think something like one 
point data something that sounds to me like a very low voltage

it is bugging me that i don't know where those seven point five k 
resistors are because i know i fairly recently restocked those and i 
thought i put them in the bins back there
but they're not where i expected
the way these things work very likely
i'll find it like two minutes after i end the stream today

but for now i think i'm just going to like i say prep press ahead there 
okay three ninety k


hey what are you creating a chauffeur nicholas asks well i am building 
yeah i probably should do a little intro here i am building and 
eurorack synthesizer modules these are electronic musical instruments 
or parts of them
to to
you you slot the modules into a
into a
somewhat standardized racking system
and then you can put together your own usually analog synthesizer by 
connecting the modules with patch cables
i run a business called north coast synthesis
in which i sell these modules i also sell do it yourself kits for 
building them
and
right now more specifically i am working on counting out parts for two
leapfrog vc f's without panels normally i build a module and it has a 
an aluminum front panel but
i recently did a whole big project of custom painting panels so i'm 
going to be posting
the photos on my on my website of the the new custom panels each of 
which is one of a kind and i'm hoping that people will want to build 
assembled modules with those panels and then the idea is i'll have a 
module ready without a panel and then when someone wants a specific 
custom panel i'll put that panel on and sell it
to them
i think i will do just two more resistor values here and then do my my 
slide show because the custom panel slides are kind of neat to see
but that's basically what what i'm up to now i'm going to put in the 
chat
vi
my storefront to website link there
i
twenty
and that may then you can at least see what some of the products look 
like

this stream which i run
every monday starting at three pm eastern time in north america its 
usually me working on something related to my my synthesizer business 
although
exactly what it is varies a bit
today its mostly the
mostly the
naked modules






sounds like we've got quite a storm there outside my window


okay so there's
the nine tens and that's this page done except for those seven point 
five k resistors which i really don't know where they've gotten to
but i'm going to put up my slides here
yeah okay so this is what i did or i started with
some test panels these are actually discarded circuit boards that were 
either obsolete or defective or similar
and you can see that different techniques i i tried for painting these
there was mass painting these last few with the pokemon are all the 
hydrographic dipping where there's a printed film that goes on the 
surface of water and then i dip it into it that's a fairly complicated 
and error prone process i needed several law to test now here's one 
that's done with the mass
asking tape masking and then here's another one that's dipped but using 
free form marbling those last three were all the
fixed sign bank now we're onto some active switches more masking more 
dipping
and here's one that was done with the printed hydro graphics
and now we're onto the qoyllur and i did a bunch of of coilovers the 
thing is i was using as the sort of base for these i was using the 
mostly some defective ah
defective
boards that had been printed with the wrong ink colors so i sanded all 
of that off as you may have seen in some of my previous streams and 
replaced it with my own decorations here
so it was largely shaped by what kinds of defective or otherwise 
discarded to panels did i have there were a lot of coilovers there will 
be a lot of leapfrog coming up
i
in the chat shelton over nectar says oh you want to power them over usb 
and manipulate the analog music signal and they're not really usb 
powered that these modules are powered by
buy a specific
rec power supply standard that is mostly plus and minus twelve faults 
the usb aspect is because i'm building a module now in my next product 
is going to be one that is
a usb host so you plug other usb devices into it and they can be used 
to generate to control voltage for a room for your synthesizer now on 
the slides were onto the leapfrog
and i'm surprised that it just showed me it seems to have gone back to 
the start
so i don't know
if my if i didn't get all the slides into the into the list there or 
what i just set up that slideshow moments before i started the stream 
today
so i don't know what's up with that but that's another thing that i 
think i will go into offline
anyway yes the
the usb module has been a quite an adventure and one of the things i'll 
be looking at today i have i bought a protocol analyzer used off of 
ebay and that has not yet arrived but i think i need it before i can 
make much more progress on
debugging the device firmware for that but one thing i do want to test
is going to be overloading it on this device here i i soldered together 
is a dummy load depending on how i set the jumper as it'll draw either 
a reasonable level or a sort of a borderline level of power or way more 
current than the device is supposed to support so i'm going to plug 
that in here
currency if this thermal fuse which is supposed to protect it against 
overload see if that actually kicks in and works or if the whole thing 
goes up in smoke or what so that may be exciting but that's not the 
current thing that i want to do the next step is going to be counting 
the war resisters lips
for the second board to okay that was board board three there that i 
just worked on
which is now done x or i've got all the parts for it except the seven 
point fives
now i want to get in the other other resistors for for board too
so that'll be two of these one kb sisters

per board so four total



these resistors here are one kilo one which means that the ratio 
between voltage and current is one thousand
if he wanted to get a current of one amp through that you would have to 
apply voltage of one thousand volts now you couldn't really do that 
because in that case they'd be dissipating a kilowatt each and they 
they go up in smoke
but a more realistic level of voltage and current would be like one 
volt across this one mila amp
and if you're not overloading the power the power capacity of it
it will maintain that ratio of one thousand whatever voltage you put 
through it you get one one thousandth of that is the current and 
whatever current you want to put through it you have to put one 
thousand times that current fault
i
and that brings up a point that i have barely mentioned so far which is 
power how much heat basically are you or is it or how what rate of 
energy dissipation
are you kidding
and that's related to or basically is defined as
the product of voltage time is correct you remember i said that
voltage divided by current is the the resistance the resistance or the 
impedance
but voltage times current is going to be the power
i
going back to the
and going back to the bicycle example if i have really high torque but 
i'm also moving my legs very slowly or not at all
then i'm not actually doing much
and that's low power the voltage times current is is locked on the 
other hand i could have
i i could be moving my my feet really fast but with basically no 
resistance
and in that case its still
basically no torque in that case its still very little power i'm only 
really getting power and accelerating on the bike and so on
when i'm somewhere in between on both
okay i'll need to listen to you more so that i can understand your 
project and yeah i i hope you will
i am
it its an i because i'm sort of in the middle of
doing multiple things here its a its probably not the easiest stream 
to start on
but i
but modular synthesis is a certainly a fun hobby
i
if you think of an acoustic instrument like a like a saxophone as the 
example i like to cite you've got different parts to it you've got a 
thing that makes a noise that read that you blow on
and that by itself doesn't make a very musical sound but you plug it 
into the body of the instruments and that shapes it by
actually by impedance matching but we don't need to get into that 
debate by emphasizing different different tones in the sound from the 
read
and then you've got other parts that are like the the keys for choosing 
which which note will be played and you've got the performers breath 
and lips and tongue that are used for shaping when do the notes started 
stop each of those can correspond to a different part
have an analog synthesizer you're going to have something that creates 
a signal its an oscillator you're going to create have something that 
shapes them to create a more musical tone that would be usually a filter
these modules i'm building right now are filters
in a modular in in a sort of a an all in one analog synth
all those parts would just be included as parts of the the the circuit 
you wouldn't see them separately but in a modular synthesizer each of 
the modules you can buy is one of those functions and you put them in 
your rack and then you connect them together and you can potentially 
get you say well i really like the north
coast filter saw by north coast leapfrog but i also really like i dunno 
what the mutable instruments oscillators or by one of those and put 
them side by side in the rack and connect them together
this is basically the geek easiest way possible of making music and to 
be honest many people who do it aren't really all that interested in 
the finished musical product they just have fun playing with the modules
i like to say that what i'm building here really is a toy that makes a 
noise
ah that that's how i think of it anyway
ah here we go here are the seven point five killam resistors that i was 
looking for before and they are in
the bin that they should be in so i don't know why i didn't see them 
before question are they high pass and low pass filter this particular 
filter here is low pass only
i have some other filters that i'm working on these ones here these 
corridor filters that are multi-mode the the it its actually a 
highpass lowpass and bandpass in one unit and they come out in three 
separate outputs
low pass passes most often
what you want in synthesis because that's how you get sort of realistic 
or natural sounding sounds
in sort of the subtractive synthesis which is the classic way of doing 
analog synthesizer sounds
do you what you do is you start with a signal that has a whole lot of 
harmonics in it such as a sawtooth wave
and the sound of a bowed string if you could separate entirely from the 
body of of an instrument and just listen to the string the the bow 
scraping across the
string that actually comes out is something very much like a a sawtooth 
wave so then you feed it through something like this leapfrog filter 
that mostly cuts off the high harmonics and leads through the lower ones
and you end up with something that sounds not exactly like an acoustic 
instruments but it sounds sort of plausible it fools your ear into 
thinking that you're listening to a physical object of some kind that's 
making a noise
and its a fact that naturally produced sounds very often the sound if 
you like hits hit a gong with a hammer or whatever and the sound starts 
out with a lot of harmonics and then it gets pure and focuses in on 
just the fundamental and
lower harmonics so what you kind of want to have is a voltage 
controlled filter that which is what these are
you would feed in addition to your signal that your your audio signal 
that has all the harmonics in it you feed a control voltage that starts 
out high at the start of the sound and then decays or releases and that 
causes the filter to close down and remove more and more harmonics as 
you go towards the end of the sound
and that pulse the shape of it is very important for controlling how 
the sounded would sound i don't have any right here but i also sell an 
envelope generator which is something that shapes the pulses for for 
exactly that kind of purpose
oh
so there are a whole lot of sort of naturalistic effects
i
that you can achieve using the different modules
and get to get something that's it it sounds like some kind of musical 
instrument that its not necessarily a musical instrument that 
physically exists you get it by applying these different electronic 
building blocks that's kind of what i think is really cool about analog 
synthesis is the sort of mapping between the very
abstract and you might say inhuman
electrical things that you can do and the the sounds that that come out 
that
often sound like they sound like music and they also sound like they 
could be physical objects
alright so i
just put those seven point fives in the wrong bins here but that is 
easily addressed
i should be putting them yeah these other bins that i worked on before
can i check those off
and so now i'm ready to work on these five point six kilometers sisters
five point six cologne or the ratio between the voltage and current is 
five point six page says check out vc react to learn more about modular 
synthesizers yeah
now why
if area salvatore trees sometimes tunes in here were around she could 
tell you some things about pcb react but
i don't really have a horse in that race so
i probably shouldn't comment for her
album
that there are a number of software modulators okay there's as well as 
vc v rack there are things like supercollider i use one called c sound 
although that's mostly because i'm a weirdo i can't say that i would 
recommend season for beginners
but certainly there there's ways to
simulate this whole sort of environment of modules that you connect 
together
there's there's ways to simulate that inside the computer that each of 
these modules can be you can also imagine a piece of software that 
would take the numbers and apply the different effects
and and there are some advantages and disadvantages to that one of the 
big advantages of course is that with a software modular basically you 
can have as many modules as you want
whereas
with a with a conventional analog modular if you want to play two notes 
at once well then guess what you get to buy two of my rather expensive 
products here
two
and two more of each each of the other modules
yeah anyway i i i didn't mean to to open open the the question of
area's problems with the cpu rack
i i probably shouldn't have mentioned it at all
like i don't have enough problems of my own i basically have quit using 
what is now called modern winkler because i don't like the 
circumstances under which they changed their name
even though i would have to agree that its easily understandable that 
the old name would have been offensive to some readers
i
yeah you know just like any other hobby
modular synthesis then there are the there's the opportunity for people 
to have
political concerns and feuds and not like each other and so forth and 
so on
especially now that i'm selling these commercially i try to stay out of 
a lot of that stuff
yeah mod with gloria is what its called oh and its the the other the 
other site that we all know is now gear space because its its 
offensive to be a gear slot now i guess
i was never really a big fan of the site that is now called gear space 
anyway
that people on the site that is now called mod wiggler always kind of 
looked down on those people but there you go that's a
if people aren't going to people is what they're going to do if you see 
what i mean
and there's no escape from it even in something that seems like a very 
geeky and technical hobby







i can't have a
a
a series of articles on my own website actually that talks about moduli 
synthesis sort of from the the point of view of someone who isn't 
involved
i'll see if i can
dig up the link here
because when i when i started this business which is now a few years 
ago people like my mom were asking me
what is it that you're actually doing
ah
and that that question was little more like more
a little more welcome than the other question which was how have you 
done any market research
i
eventually got to the point where i was basically just saying no i 
haven't two people who asked me that because what the heck am i 
supposed to say after being asked ten times you know if you won
having done any market research before quitting all your other jobs and 
starting a business
do people seriously think the answer is going to be no
evidently they the many seemed to think so and because they hadn't ever 
heard of modular synthesis that there was sort of the assumption that 
there was no market for it and that i was going off
off the deep end
but there we go that i just put in the chat the link to the start of my 
my intro series
i
also i mean apart from just being tired of being asked that there's the 
aspect of wanting to mess with people's heads
our
friend of mine who at the time was in his thirties
he became romantically involved with the
women who are
with a woman who was in your fifties and sometimes people would ask her 
who is that your son
now of course they didn't mean any harm by it they probably thought he 
might really be her son but she wasn't really thrilled to be asked that 
so i told her okay here's what you've gotta do when they ask you is 
that your son you say yes
then you give him a big kiss and start making out with him right in 
front of him see how long it takes for them to figure it out
no i mean you can say that that's like oh yeah this is a way to turn 
the situation around and turn something that was uncomfortable for you 
into something that'll be uncomfortable for the other people really 
though the real reason for doing that is just how many times in your 
life do you get the chance to mess with people's heads right
let them think even if they figure it out within a few seconds let them 
think that you have this completely inappropriate relationship with 
your with your adult child
alright
that's the second board done i see the second board i number them 
basically in reverse order because i number them from board one is the 
one behind the panel
back to in this case board three
and so now i get to work on them
on board one
i
these
i found out once i started this this little batch of naked modules i 
found out that i didn't actually have enough of these fancy panel pots 
for all the modules i was planning to build
and my supplier did not have the kind i normally get in stock now the 
kind i normally get cost like four dollars each they're quite expensive 
and they were out of stock on those so i put a put in a large order but 
they won't be expected until i think august so i ended up buying just 
five more
of
these other ones that look nearly identical but they're like almost 
eleven dollars each because they are the special sealed ones they don't 
have exact they're a little stiffer on the knob feel
i
just so that i could complete this batch but after that i'm not going 
to have any more of those until until the more arrive fortunately my 
stock of finished modules is in pretty good shape so i'm not expecting 
to run out really soon but there may be a little bit
if a supply crunch if i have to build more of these naked modules if the
if the custom panel ones are as popular as i hope i may have to say 
well sorry we're going to have to wait till august to get somewhere of 
those because i can't keep paying eleven dollars each for those those 
panel parks not if i'm going to be keeping my existing already high 
prices for finished modules anyway
but that's the fun of running a small business in in plagued times 
mostly i've done pretty well actually
i haven't at least in this these most recent waves of covert i haven't 
had any really serious problems from a supply chain disruption
so we can hope that that'll remain the case



this leapfrog the cfs you you can tell from the model number there is a 
zero zero seven its ah
its one of my earliest designs
and its one that i had originally just intended as a hobby project 
before i knew i would be doing this as a business so its not really 
the most commercial design in particular it has a lot of different 
resistor values in it
whereas if i were designing
designing a new module today i make more of an effort to reuse the same 
values in multiple places so that i might have like five of a given 
value and correspondingly fewer different values instead of having to
instead of having to count out oh yes one of these and two of those
and yeah i need to have these two of that two point seven
the other thing with leapfrog is that its got lots and lots of little 
tremors which really are kind of a pain to adjust
i
one of my early module designs which i never commercialized and 
probably never will it didn't work all that well but i had the idea 
that i would
i had a lot of different adjustments in the temperature compensation 
circuit and i was living in denmark at the time and diarrhea
in order to
testing that adjust that
i had to heat and cool the module to a bunch of different temperatures 
so i was taking it in and out of the refrigerator and putting it out on 
the balcony of my apartment and so on
to try and get a good handle on how it was behaving with respect to 
temperature
and that was sort of fun to do once with the hobby project but i sure 
wouldn't want to have to do that with a commercial product
that one might end up having to be a do it yourself only

but really i've found
people don't even care all that much about accuracy
that sort of objectively measurable features of a module
i know its more that they want he wants there'd be a good story for a 
product
just like buying anything else again i mean i said earlier people are 
going to people and they they are
its the same with this business or any other


yeah
okay five point six next i'm trying to keep an eye on where everything 
is on the screen here so that you can see it
five point six











the usb host module
basically the concept is i want you to be able to plug in
many different kinds of usb devices and have it do something useful 
with each of them
and one start design goal was i wanted to be able to have it reload 
its own firmware from a usb memory stick
which is actually a fairly tough problem because then you know there 
are multiple layers of it has to talk to the usb port and it has to them
talk to the memory stick and it has to understand a dos file system and 
so forth and so on but i'm actually not expecting that people will 
reload the firmware all that often that's not something you do often 
with a with a device
so
other things that you can plug into it
i
one of my ideas is that you should be able to plug in a
a mouse and then control your synthesizer with that like the x and y 
coordinates come out as voltages on the
and the buttons come out escape signals so you can play music using a 
mouse which may not be the best kind of controller but its something 
that someone given that they have a module that can do it i'm sure 
they'll plug in plug the mouse into and enjoy playing with it for a 
little while
i
and i'd like to be able to plug in a keyboard
a midi keyboard like come
a usb midi like this one
is really sort of the intended application but i'm also thinking that 
it would be nice if people could plug in a typing keyboard or a qwerty 
keyboard and play notes using that
so at this point
i actually got the mouse working pretty well although sometimes it gets 
some kind of a usb error and crashes
and i'm still not sure what is up with that
i
the typing keyboard does not work well
at this point in time i'm hoping that like
late this week early next week i'll get that analyzer that i ordered
and that may help me figure out what's actually going on on the usb bus 
and why these crashes are happening
usb is ridiculously complicated standard
and to
and of course they really want you to join the implementers forum and 
pay thousands of dollars a year the dues and so on so they're not 
easier to provide
useful information for implementation
in any kind of freely available way
and also the usb standard is designed to shift most of the intelligence 
from the device to host right the ideas that usb devices can be 
relatively stupid
and all the all the work is done by the host but what i'm building is a 
host so i need to end up actually doing all that work
its an interesting adventure and it is getting me back into 
programming a bit which i haven't done really in a very long time and 
that's kind of fun

okay have twenty two and twenty seven k here







here we go
its always a little bit of a thing trying to find the end one of these 
big collections of
tape three sisters










and the twenty seventh








okay next is thirty nine

looking a little low on these but i keep a fairly elaborate inventory
of all the parts i have on hand
that's what these are
papers i'm pushing are for
so one of the things i can do is i can get a a report that shows what 
am i low on and how many more of each of my products can i make with 
the current inventory and which items will run out first
so after i update from these record i'm making
that will show that the thirty nine k resistors are low
unless i already have a package of them which i might actually oh yeah 
i do i already restocked these so here's then the next package
but if i were actually going to run out it would tell me and then i 
would know that's the next thing i have to
how to buy
the trouble is of course when its something like these pots yeah okay 
the inventory system tells me hey you need more of these but then i go 
to the supplier and they say well not before august kiddo
thinks she can hear

so just because i know its reorder time doesn't mean i actually get to 
restock immediately



i think my accountant thinks i'm nuts because
his view basically is that you shouldn't keep any more records than the 
government requires because
the fewer records you have the fewer things they can get you far which 
is you know it makes sense given that i mean part of his job is to keep 
me from getting in trouble but
from my own perspective
having this detailed inventory even though it to even though it costs 
me a fair bit of time and effort to do it is really useful
knowing exactly what i have or what i'm supposed to have in my bins
that that has helped with debugging a number of different problems like 
at one point when i had a batch of defective knobs
and i didn't find out about this until after i'd already shipped some 
of them to customers i was able to figure out okay how many possibly 
defective knobs dude i actually ship to whom what can i do about it i 
ended up just shipping replacements to everybody who could have 
received one
okay the question is how would you know which key is pressed on the 
keyboard or are you accepting the midi protocol well for the
for the usb midi
keyboard yes there is a usb midi protocol so i just read read that 
information
its basically the usb midi protocol just consists of sending usb 
messages inside usb sending midi messages inside usb packets so that's 
not a terribly difficult thing for a typing keyboard there is a 
standard usb typing keyboard pro
protocol which i am attempting to accept
its not completely trivial
the
the keyboard has a has an interrupt input in point is what its called 
in usb speak
and when its ready it will send you a eight by packet
that has one bite that tells you which modifier keys such as shift and 
control are pressed in one bite that is reserved and you're not 
supposed to look at that bite and then six more bites tell you which 
six up to six keys are currently pressed so you have to keep track of 
what was the
previous reports compared against the next one oh there's a key newly 
pressed or there's a key that is no longer on the list that sort of 
thing
i
the thing is the usb standard has this incredibly complicated protocol 
for what they call human interface devices which includes keyboards and 
mice and stuff like arcade buttons and as far as i can tell almost 
nobody actually implements that protocol instead they use the 
simplified one
which is still complicated so the simplified usb keyboard protocol is 
the one with the eight bytes and six bytes and so on that's what i'm 
doing
the problem that i'm having actually isn't at that level of the 
protocol its with getting the usb device to stay connected at all 
because there's all this stuff like if the usb device doesn't hear from 
the computer in three milliseconds then its supposed to shut down all
automatically
and if that happens then you have to go through a procedure to wake it 
up again and so on
there are certainly reasons that people like to stick to analog
but
this this digital usb protocol is basically where where my journey is 
taking me at the moment

okay so
now these hundred k resistors
its a funny story they come basically in packs of five hundred and 
five thousand this is one of the five thousands
i ordered one thousand resistors
handshake and time out issues yes as well as possibly signaling issues 
because
i most recently i've been getting disconnects
when there shouldn't be
and i think that may have to do with the differential signaling
usb for ordinary data transmission it uses differential signalling 
where one line goes high at the same time as the other goes low
but it also does this thing called a signal single ended zero where 
both lines go low at once
and that's used to signal things like
let's see the connect disconnect
i sleep there are multiple different things that can happen that that 
are signaled by by single ended zero depending on like how long it 
stays in that state or which end of the connection pools it there
i
and i think some of that is happening when it shouldn't anyway these 
hundred k resistors come in five hundreds and in five thousand units 
per box
i ordered one thousand so they were supposed to send me two boxes of 
five hundred
and instead they sent me a five hundred and five thousand
ah
so i emailed them you said you know i don't mind paying the difference 
but these people that was newark element fourteen they they don't know 
what they're doing
so they never they never resolve that and eventually i said okay fine 
i'll just keep the extra four thousand five hundred

but it does mean i now have a great big box of those
it'll be a while before i have to reorder them in particular


i don't really know what actually is the current issue with the with 
the mouse in particular
i
but that is something that i'm hoping that this
this analyzer device i bought will help with basically its just a 
thing that watches the bus and records everything that happens
one of my twitter contacts asked me well why don't you just have 
software on the pc that reports the bus and the trouble is there is no 
pc right and unplugging a mouse or whatever into my my homemade device 
or mike may do
so the only way to get a pc onto the bus to to listen to it is is to 
use some sort of special hardware and that's what this thing i bought is




alright to forty ks next
go
one of these in each bin







i am trying to make usb easier for myself by putting a bunch of 
limitations on it for instance i am not handling hubs
and that in turn means i don't have to handle more than one device at a 
time

but i do have to handle both low speed and full speed
full speed being sort of a medium speed
those are i think one point five megabits and twelve megabits per 
second respectively
you can go faster there's a usb also has a high speed and then the next 
level is super speed and so on
but full speed is about the most that my microcontroller can handle and 
that is a level i have to support because
i need that for talking to memory sticks






okay where's the bin of
high resistances here we go i don't know why i put that
where it was on the shelf i was the wrong place for it

four point seven manx

if i remember correctly these are for setting the scale of the year
fine tuning knob
four point seven mhz means the ratio of voltage to current is four 
point seven million
so for a given fixed voltage you get a very small current whatever 
volts city is divided by four point seven million
and that's useful in the
for the tuning knob because there's an op amp input
that is basically being driven by current
and as you adjust the fine tuning knob you're getting very small 
amounts of current
for your front for pushing the frequency up and down
alright that is
board one done
and that is all the parts i need to count out at the moment for the 
leap frogs
so what's next on the list on the octave switch
its ready to go
don't need more parts for that coil or board two is ok
interesting currently forgoing is ok as well
alright
so i guess that means i move on to the
board two of the
middle path vcr but i would like to say take as they say a bio break 
before doing that so i'm going to put up one of my other slide shows
for about two minutes
and i'll be back soon
and
the
the
the
the
the ok
so now i'm back to counting out parts of various kinds for the middle 
path visio which is my most recently released product this is something 
that generates the original signal like like the read in the the 
saxophone
i
and the signals from the this is i well i mean there's there's sort of 
the north the east coast tradition of synthesizers which tends to be 
subtracted synthesis like like i was describing before where you start 
with a harmonically rich signal and then you remove harmonics to get 
the tone you want
and
and then there's also what's called the west coast's tradition which 
among other things involves trying to build a
an original signal that will have interesting harmonics in the 
proportions you want right from the start and then doesn't so much 
needs to be filtered
and this this oscillator is kind of in between those that it has to 
with a sort of classic
classic east coast course but then it also has the special wave folder 
section that or wave shape or section really that is designed to give 
kind of a west coaster sound to it
that kind of fits in with the name of my company although that's not 
the only reason to build it this way
so i'm making two of these and there's two boards each so i have a 
couple more empty bins there for the the other board
and i'm going to start with these hundred puff capacitors which are in 
our school back here

the end
nine of them per board

these are mostly stability capacitors for the op amps on all the outputs
six



the and i'm going to have
twenty
of the axial ceramic caps skipping over the film for the moment because 
they'll be in a different bin

when i bought these i thought they were going to come on a roll which 
is the way that i usually want them
but in fact they came as bulk
so i'm trying to use up for assembled modules the bulk ones because 
those are not as nice to pack and kits and send to my kit customers
five

ten
fifteen

twenty
i mean they're the same capacitors either way its just a question of 
how they're packaged but
its nice to be able to give the kid customer area
a chunk of little sort of ladder tape
five

ten

fifteen
twenty


that's all the ceramics so an extra going back to one
film caps
twelve hundred

and two of them prevent




can see from the way this is packaged to this is just a chunk of tape 
off of one of those reels
but because i bought them in a smaller quantity do they don't send me a 
whole real


i'm less cautious about labeling here when i know that i'm going to be 
doing the assembly myself
for the kids i try to have everything really nicely and clear
ah
because people building kids aren't always as confident about them
identifying a component just by looking at it
and also some of them are labeled like these these hundred puffs are 
labeled in teeny tiny twinge


two of those
two to those
aluminum electrolytic caps here

now we're getting into the power components
actually these electrolytic caps are powerful finance to their forum
filtering the incoming power
but we got these
schottky diodes


diodes are a place where the water analogy for electricity
is really appealing because they're pretty much just like check valves 
and plumbing are meant to let the current flow one direction and not 
the other
and just like a check valve
there's going to be a certain amount of back pressure that you have to 
apply some pressure to get the
get the current or the water to flow through it at all that reduces the 
available pressure on the other side
that's called in the case of a diet that's called the forward voltage
but then if you if you have pressure going the other direction
the diode is supposed to close off and not let current flow
and if you've got a check valve and you apply too much back pressure to 
it so it doesn't zone
against against the direction that its trying to block it'll burst and 
the water will flow through anyway
similarly with these diodes that they can burst
breakdown as its called
i
and with a schottky diodes in particular
i
they are a little different from other kinds they have less less 
forward voltage than others so that means you lose less pressure when 
the current is flowing through them in the intended direction
they're sort of moderate in terms of their breakdown properties that 
breakdown voltage is high enough not super high for this application
they also have a little bit of leakage in the reverse direction
so even when they're not breaking down there working the way they 
should there'll be a little bit of current that sneaks back through
which is not really a problem in this application because they are only 
being used for protection normally
there's no question that your current is going through in the forward 
direction
but if it were at a situation where i were routinely putting in and the 
the point is just that on the euro rack power connector
its often very easy i mean here's the un polarized plug that goes on 
the m
board
fits into the power connector like that it could for the infinite fit 
in backwards
so i put some of those schottky diodes in series with the power on the 
board so they won't tongue
it won't actually end up applying a significant voltage in reverse 
truly more delicate components
okay so at this point i need these three nato force
but that pack is not opened yet they're probably got a closed one
a smaller one that's yeah
so draw from here first

generally my goal is to take from whichever pack has the fewest units 
so that i will be using up the packs faster and that stable right after 
i remove one or if i have one pack that has fewer than the others and i 
remove one or two from it it'll still have fewer than the others
so this encourages me to use up the oldest ones first even though i 
don't have to keep track of which one is actually oldest
so here's ten
and there's thirteen


thirteen with a three or four general purpose transistors

he was five
ten
there

yeah before handling these twins seven thousands
i want to get my
anti static strap on here its probably not really necessary but
feel better having that
because these twenty seven thousand or mosfets
they're potentially delicate with respect to
static electricity
i guess i should also test those
when i was developing this module i had some problems that at the time 
i thought traced back to having destroyed some of these transistors 
with static
now i no longer think that
i now think that my problems were actually just that one hundred ring
but
i'm still kind of paranoid about possibly just joint blasting these


that one i think is good
thing is i've am now no longer sure that i've ever actually seen one 
destroyed by static
all the cases i thought were then at war i i now ascribed to some other 
corners
so i'm not sure anymore that its really a significant issue or even 
exactly how to recognize the difference happened
but i'm still shipping a spare in each kid
if someone buys the kid of parts to make one of these
middle paths even though it only really uses two of these transistors 
they get three just in case



but when i'm
counting them out here forever for my own use i counted out too
if i discover that one is dead later i'll replace it then

see
as i did last stream
i think i'm going to skip over the resisters
for this build and just count out the other parts
cause i basically had my year
had my fill a question do i know if they are good based on the 
resistance i hope so now what i was measuring there really wasn't 
resistance it was forward voltage the
on the the multi-meter was set to diode test and in that case its 
setting sending i think its one mila and fix current through the 
device and then it measures the voltage that that causes so what i was 
seeing was a reading in one direction of infinite meaning
note and effectively no no voltage that it would send would be enough 
to send that current through and in the other direction it was reading 
like six point two point six two or point six three which corresponds 
to one forward silicon diode drop so the thing is these transistors
as
they're supposed to not let any current through unless the gate is 
activated and the gate is delicate it can be destroyed by a static 
charge and i think what happens is that if the gate is destroyed then 
it will start letting through currents regardless
but these also in order to protect them against a different hazard they 
have a built-in diode across the transistor so i think when i'm 
measuring infinite in one direction and point six two in the other what 
i'm seeing is that diode the diode is conducting and so that means that 
i not seeing a lower read
the lower voltage which would indicate that the transistor is shorting 
out these transistors when they turn on normally they would drop a very 
small voltage and i think if its destroyed the usual cases that then 
it starts turning on all the time so basically yeah i'm hoping that 
they are good based on this voltage
measurements although as i say i'm no longer sure that i've ever 
actually seen a bad one so i'm not absolutely certain what a bad one 
would look like
but my hope is this is a way of of determining that they're not then 
they're not bad
okay so the next item on here
its going to be the horizontal single turn ten k re pot or tremors 
actually

there was this whole thing on mod wiggler
of people complaining about what they called trim pots
by which they meant
panel parts that have a plastic shaft and no knob
i don't know why people think those are called trim pots
but at least on that web forum that is what they call them now
and you're just shouting into the wind if you say no no a trimmer pod 
is one of these


yeah i knew i'd restocked these recently so i was looking for my other 
being of them
because ah
i need to purr purr been in to i have three in this bank

so i take all of the three old ones
and put this bag back here
and then i'll need one from the new batch




okay then there's a bunch of resistors
which i'm skipping over for now and then it'll be dip sockets
dip sockets are another item that i recently restocked and my supplier 
was very low so they sent me what they had but then the rest have gone 
on back order
so you know here's let's see it says
how many are in here twenty seven dip sockets of a fourteen pin kind
to top up my stock here but i'm not even going to be using all the old 
stock at this point
because i need ten of them and there's more than that in this round





five in there
and five in there
now the eight pin edition
oh i grabbed the sixteen so i might as well do those
and two sixteen pins
as usual i take from the rail with the fewest in there
so that i'm be using up this real rail before starting another

two and two
and finally the eight pins
and i need for these new spin





four and four
that's it for that page

yeah i still have to do for one
again this is in reverse order for two first and then bought one there 
are only two boards in this particular build
i
so these gets sixty eight hundred puff
film resistors
film capacitors



two
and two

and its more of the axial ceramics


from the box five in each bin

five

five


and the electoral politics
just one for this sport




switching jones
these call for a bit of caution because i also have zener diodes which 
look pretty much identical
there's some basically microscopic writing on the little little glass 
body there that says which is which but
not eager to try to decode that so
i'm trying to keep them separate





and seniors
the thing with a zener diode
like other diodes they can be thought of as being similar to the check 
valves they permit current to flow in one direction and not the other
and if you apply a voltage in the other direction
if its enough voltage to sr will break down
the thing is though that with a zener diode its designed to do that 
without being damaged if you keep the current limited it can breakdown 
reversibly without without any harm
and it does that add a controlled and to known voltage
so its useful for regulating voltage
you get your power source with a controlled current level and you apply 
it backwards across the zener
and i need to cut out two of these
and the zener breaks down and it draws as much current or it lowers the 
voltage to the level that matches the breakdown voltage
so this is using the middle path oscillator actually as a voltage 
regulator i need to have
reference sets negative five false
it doesn't relate to supply very much power at that voltage i just need 
to have it
so
i force these zingers into breakdown mode and to
they keep their voltage where it should be


squinty at the printing here to make really sure that its
what it should be two three
b
zero
i got this right
he
not what i expected it to say
oh i see its because i have a different model here these are actually 
a five point twos
which is close enough

yeah yeah its not two three one zero its true three one c which is 
what it should say ok
this one
say thank you for the stream must go now its night in germany wish all 
the best thank you for tuning in and you can subscribe if you like or 
see the
the end of it on t v o d by
yeah ok so now i'm going onto hardware







four
and




offs








i like to arrange my stand offs and sets of four here
to keep them together and to easier to count




in the eleventh
between ten and eleven doesn't seem like a big difference but very 
quickly learn to recognize
which is which





okay

nuts here

for those as well







you know these require twenty of the
lumber jacks but i think i'm going to leave those for later because 
they are a pain to counteract

why even have yeah i do but they're there in the other bin
just checking down here where they keep those jacks if i had to enough 
of them

grip that wrong there too
i saw a little
alright so these males we get three of these in each bin
the females which are in the other bin
i knew i was going to run out so i restart those recently
the new ones are in the package that came
late last week




but actually with only two luck
i'm not going to need to open this new one quite yet
free
and three
alright so its quite transistor save for later resister save for later 
still multi-terrain pot



okay i
fifty k horizontal multi-terrain

some in there
do you have any others
huh

not just these



two three
and four


similarly with the
panel parts which fortunately i do have a lot of that model
i'll save them for later
candle for the dear pisces

yeah
the non i see i think i'll put in now




toggle switches
i dropped that in there and then i thought better of it because i want 
to put on the hardware for it as well




locking ring



lock washer



true nuts



i'll have to take all that hardware off again when i go to install it 
but
i like to put it on here anyway
so as to keep everything together
make sure that the different bits don't get lost or confused with others




okay
or in the homestretch here i just want the duties seventy one ones
and then i'll have a few dip sockets to put in
and that'll be it
yeah
dip sockets one each fourteen and eight

the fourth
that's eight
okay
sixteen goes back on the shelf pick up these aids

for feelings i'm not using it go on the shelf


there's the fourteenth

these go back on the shelf


two of those




and that's that done
so the next thing i want to do
she's only slightly related
his deal with this summer
current test
so the idea is that when you plug the device into worked host usb
the device is powered by the usb bus
and there's a limit to how much current the device is allowed to draw
and some devices want to have a lot of current because they're like 
charging their batteries or whatever
the the official standard is that the standard device unless it
unless it speaks to the special protocol to request more power its not 
allowed to take more than one hundred milliamps
so this
host
it doesn't have a lot of fancy power control in it
what it has is this they call it a poly fuse its not really a fuse at 
all its a a thermal resistor under normal circumstances its low 
resistance it doesn't drama shot it doesn't consume much power it just 
passes the current right through but if you putting too much pop if you 
draw too much current through it
and in this case the limit is supposed to be two hundred mil amps
and then it starts to heat up and once it heats up its in its 
resistance increases so it will effectively shut off it goes to a high 
resistance since doesn't allow current through so that that's a safety 
feature if you have a usb device that draws too much current you do
i want to let it do that it could cause the power supply to fail or 
something so the thermal fuse heats up and shuts off and does not allow 
the device to draw excessive current
i tested this
also this usb host the manufacturer of the main microcontroller chip 
here their documentation leaves something to be desired
they recommended in the data sheet that you should setup a voltage 
divider and hook it up to one of the analog digital converters in here 
so that the chip can measure the voltage on the usb bus power supply
and they don't really explain what its supposed to do with that 
measurement but i think the idea is that if you overloaded in the 
thermal fuse trips then the voltage will drop and the microcontroller 
is supposed to recognize that and no okay there has been a problem
so i have implemented that i've got the voltage divider i've got 
software on the chip that will measure the voltage and tell me and 
caused the the thing to shut down if
if the voltage drops indicating that the fuse has tripped i don't 
actually know that any of that works so i have this device here that 
i've built that is supposed to draw a controllable amount of current 
and i can set it to an innocuous level or near the limit or way over 
the limit so
i'm going to put this thing up plug in this and see what happens
right now it is configured to draw an innocuous level now for further 
safety here
couldn't risk doing this
but see i'll see if i can get it so that you can see the
power supply there
there we go
this this power supply has a
has a current limiter if its on
so i'm going to short out the power supply
this is actually the recommended way of doing this in the manual
and
alright so the current limit is currently set to two hundred milliamps
it will not allow more than that much current through
i'm turning it up
i want it to allow at least five hundred


five twenty that's plenty
alright
so if something really goes wrong that's that dummy load is supposed to 
draw a four hundred seventeen
and there might be you know about another hundred that's used by the 
device itself by the host itself
so
i'll just
get this back the way it was and that's upside down i think
yeah that's right way up now
alright
its more or less the way it was so here's this this cables connectors 
about power supply i was dealing with a moment ago
and i
i have this debug
debugger thing
i'm running a microchip
p lab on the other thing i guess this should be powered up first

so i'm just gonna get into mp lab here on my computer and tim
start that thing running
i guess i gotta build and program first
i
firmware is building on the computer there
plug this cabling i hope that the cable is not going to complain about 
this level of load but we're going to start start simple



mp lab is even slower than usual because i'm running it on the same 
computer where i'm also running a stream control
but now its programming the chip
i have never actually tested this over current thing so although i have 
a pretty good idea of what its supposed to do and it should be pretty 
boring if it does what its supposed to do it could also be exciting if 
that's not what happens
okay programming complete
watch the bugger
and start running
okay so that machine is currently running my or my own firmware
and this is currently set up for
just these two resistors on the end
but forty mil lamp yeah okay so the current has increased to one 
hundred mil amps and those three sisters are getting just a little warm 
nothing else happens
plug that in i'll reconfigure the jumper here
so that this will now draw
about two hundred milliamps which is more than the usb device is 
supposed to sport its right on the boundary of what that thermal fuse 
will allow the thermal fuse has a nominal value of two hundred 
milliamps which means that really you have to go a fair bit higher 
before it'll trip
plug that in
two ten
nothing else happens
alright
now the possibly exciting part actually i guess i should do
the fields the thermal fuse heated
nope
everything is pretty much quiet on the western front there but this is 
now configured to draw a four hundred seventeen mil amps which is way 
more than the thermal fuse
once
so if i plug it in i don't know how fast it'll trip it might still take 
like half a minute but it should definitely eventually trip and when it 
does the microcontroller is supposed to blink the lights
three sixteen
yup there we go its working exactly like it should very nice
now i guess before i yeah
mess with that any further
the current is still decreasing i think that that means the thermal 
fuse doesn't trip
i hard
i'm just gonna
measure here the
voltage
yeah one point two
so there's still some voltage getting through there one point one its 
falling also as the thermal fuse heats up further
it is interesting that that thing just shut off
hmm
if i unplug that
target halted it may be that something else overheated also
but the basic the basic thing is is good that it did it did trip but 
didn't tell
we didn't have other things happen
now
i'm getting program halted here
and that's interesting
doesn't say why
could have been something like an oscillator fail

the microcontroller still seems to be alive
so i'm not quite sure why it didn't stay in that that fall condition 
with the lights blinking
it may be that once this was sufficiently overloaded it'll also have or 
overloaded the
voltage regulator on here
that would be a reasonable guess
basically though i'm pleased that
it was able to
the the thermal fuse did trip and the microcontroller did signal
went once at tripped
power configuration on here is not identical to what would actually 
happen in someone's synth rack
i
the run this more
and
i'm going to plug it in again at the low
the low current to draw the see what happens with that says one hundred 
mil lamp
drops to twenty
okay
i think that test basically is successful
still not one hundred per cent sure about the fact that it it shut off 
but
that's not really my main concern
i may want to do more testing of that later
i would like to have a really clear understanding of what happens in 
the case of an overload






alright that completes what i wanted to do on my stream today so please 
remember to do as they say like and subscribe but i think actually what 
you have to do on here is follow and turn on notifications if you want 
to be told when i'm streaming again my regular schedule is on mondays
at three pm eastern time
and i hope you enjoyed and have a nice day
oh yeah
yeah the
the
the
the