Planning on Ordering my first PCB for one of my first completed projects. Does anyone have any suggestions before I pull the trigger? I am planning it too either be panel mounted jacks in a KOSMO type panel or in its own enclosure. I have a power header expansion board So you can stack them if you wanted a dual joystick Box.
The Journey
Very First step of prototyping
Post of it functioning complete on protoboard
This looks great! And I want. For kosmo version would you put the joysticks right on the panel or a port for a wired controller of sorts?
Looks like a nice clean pcb. I like the art. The only things i noticed are the traces being kinda small, probably fine. And also the 4148âs at the power headerâI could be wrong and there are smart people here who could say for sure âbut isnât there a better choice? I know some of the guys like @analogoutput use 1N5817. Which is what Iâm switching to use.
Yes a front panel header with a breakout board is possible. I recently found someone modded their DOEPER A174 INTO a remote Joystick 5 pin Din socket. Which shouldnât be that hard too do. Also when I was using mine my hand was getting pretty tired after a while lol.
Sounds like youâre cargo culting after a cargo cultist.
But yeah⌠Schottky diodes are what Matthew Skala uses and I figure heâs a good role model â your schematic shows Schottky symbols but 1n4148s are not Schottkys, with 0.65V forward voltage vs. 0.45 for the 1n5817s (and 0.2V for whatever Skalaâs using, hmm, never looked into that.)
Then again, my most recent Tayda order included a bag of resettable polyfusesâŚ
More and better discussion here.
Iâve been using 0.75 mm traces for power and 0.25 mm otherwise, but Iâm not that good a role model.
Yeah I just been using 1mm and 0.75. That is overkill but when there is plenty of space, why not. I need to reread about poly fuses
Ah, okay⌠Skala seems to be using 1n5818s, rated for 30V vs 20V for the 1n5817, and forward voltage at 1 amp of 0.55V vs 0.45V for 1n5817. He says âIn normal operation they drop a small voltage (0.2V for the Schottky rectifiers I like to use)â but that presumably is at typical module current.
While I was on Skalaâs site I decided to download one of his PCB layouts and take a look at it: his power traces are 35 mil and others are 20 mil.
Edit to add:
Music Thing Modular (Mikrophonie): 32 and 24 mil.
Mutable Instruments (Braids): 16 and 10 mil.
Thanks for the trace values. Iâll make some mods to the design better safe then flaming traces. lol
You need a quite a few amps to set fire to 35 mil traces, and if your TL07xs consume that much current the traces are probably not your only problem 
(6-8 mils arenât uncommon for small signal work; if you need more for the supply traces depends mostly on trace length and number of things at the other end of the trace. Reasonably short traces with no more than 100-200 mA or so will probably not require extra attention. Also, cheap PCB fabs may not handle traces below 8 mils well, so thatâs another reason to keep it a bit bigger.)
A bit of nitpicking:
Is there a way in KiCad to tell it âput value on the silkscreen layer for all componentsâ? I know how to do it for one component at a time but not how to make it the default.
Edit: Found this: Swap reference for value - #14 by bobc - Layout - KiCad.info Forums
Also that comment on positioning is something I wanted to mention to @lookmumnocomputer. On the one module of his Iâve built (the 2399) most of the components have both designation and value shown inside the footprint, making it about impossible to figure out what is what on the assembled board.
Thanks for the tips. It will help make the design overall better and help me gain knowledge.
(schematics) The gain for a non-inverting opamp is 1+Rf/Rg, not Rf/Rg (so 1+4.7k/2.2k = 3.1Ă in your case). (Also, you cannot really overcome a (relatively) fixed forward voltage by multiplying with something; youâll reach the threshold 3Ă sooner, but you donât bypass it completely.)
The gain for the LED indication circuit is referenced to the final output Voltage.
So it is only amplifying the output signal too the point where if there is any type voltage being outputted the led can pick up of signal. So wouldnât work at displaying a linear led brightness for a indicator?
It seems too work fine, but I should change the values a bit the Point it detects signal at below 500mV.
Is there a better way too do the same thing?
My point was that since you need to get above a certain voltage before the LED starts doing anything at all, and that voltage is quite high, multiplication wonât fix things on its own; a small voltage will still be below the threshold if you multiply it by 3. But Iâm nitpicking on the text in the schematics, not the functionality â if itâs useful in testing, go for it 
To illustrate what I mean, here are the forward voltage and intensity curves for a random red standard LED; thereâs nothing linear here, and you need to get above some point between 1.5 and 2.0 V (after multiplication) to get anything to happen:
The exact voltage depends on the LED type, and most LEDs have higher forward voltages than the red ones.
Oh, this is Good to know! Could this be the reason why we have problems with the leds on the Delay here??2399 triple splashback delay - #158 by ChristianBloch
I am very interested in this pcb, what joystick did you use in the panel ? I really like the simple layout design and looking at it , it looks like a pull that trigger go project
This is the joystick I used. It doesnât have a spring. So it doesnât spring back too center.Joystick
I am working on V1.2 that is even easier too read with the values on the board and a more optimized wire routing. When I started this PCB I wanted it too be as beginner friendly as it can be. Minimal parts, Sections labeled.
defiantly interested in the pcbâs if you will have them to sell .
I am planning on releasing the files for free. So anyone can order them If they are interested in DIYing them. I mainly did this for practice. I am still pretty much amateur at designing. If I revisit the Circuit again in later revisions and do more testing and modifying the design with more features. I might consider releasing revisions as a product. Since its simple design too understand and learn from with common parts and with people order 3-5 pcbs. They could give them away too people that are starting to get into DIY Synthesizers.
You are right about this. Did some further testing the method. I am using only only displays down too 500mV. Still works well for a display. But If I want too display it more accurately. I would have too think of another method. Like a Voltage -> current control method.
I also noticed LMNC Used Voltage Follower For his Dual VCA Design with a bipolar Led. Which I was using until I came too the problem of having 2 LEDS with Voltage a Different Forward voltage. That is why I Changed my Design A Non-Inverting Amplifier too overcome that problem.
Are you going to order a few extra? Would love to get a copy from ya
I definitely want 2 serts of pcbâs this layout is very nice and tidy .great work
