Sorry the tilt is just for the photo! It can be soldered on normally, just on the opposite side to the silk screen marking that’s all.
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It’s super late here so can’t tell if I am correct to think that this other Tayda switch (A-5488) is a suitable replacement for the spec’d 3PDT ON-OFF-ON toggle (108-0006-EVX). Or is that just wishful thinking, since it is so much cheaper?
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Sean! That’s a great find… When I first designed the RGB Matrix the only sources for the on/off/on version of that switch were Mouser and one of the boutique pedal stores (I forget which one). Tayda only had the on/on version (which is nice but the centre ‘mute’ position is just so useful).
I am 99% sure I’ve used that exact part (Dailywell 1M33T1B1M1QES) from Mouser, so I am pretty confident it will work perfectly. Unfortunately I sent off a big Tayda order just one hour ago, but I’ll see if I can convince them to add that part to it so I can get some and confirm.
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Went ahead and ordered some of those switches from Tayda and, while I haven’t built up any modules yet to test out (probably will take me a while yet to find the time), I can confirm that they at least do fit perfectly fine onto/through the boards/panels. Quality seems fine.
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Important 1VR addendum!
Please populate R7 as a wire link (zero ohms) and not a 2.49K resistor like the older manual says. Be careful to make sure it doesn’t short on the potentiometer chassis though, it’s quite close.
If you are finding the variable output doesn’t go from -1V to +1V like it should then it’s very likely that this will fix the problem.
Sorry about that 
Important 1VR addendum!
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Important Gainbrain addendum!
Please populate R4 as 10K rather than 1K (as it was in the older version of the manual) to increase the useful range of the manual knob and the CV input.
Important Gainbrain addendum!
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Hi. Is there a manual for the 1SW A/B Switch module?
Would this module work with strictly an analog modular synth’s audio and cv?
Thanks for the help.
Hi belj,
It turns out I haven’t created a manual for the 1SW yet (as I wrote in that other thread). I’ll sort one out. Sorry about that!
The 1SW is a passive switch module, so yes you can definitely use it with an analog modular synth’s audio and CV signals, and indeed with almost any electronic signal you can put in through a 1/8" plug.
Cheers,
A.
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Nice! Thank you for the clarifications. This looks great and is just what I need for my upcoming project.
Hey there, just wanted some clarification before I made my life much more difficult. Could anyone here confirm that I’ve oriented these switch PCBs correctly?
Also, are letter additions to manuals just to denote updates to the manual but the board hasn’t changed from whatever previous version?
Thanks!
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Yes, yes and yes! You’re spot on 
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One more question-what’s the diameter of the switches for the input board for the matrix mixer? Unfortunately the diameter on my board is too small but I should be able to widen them with a bit but not sure what to use. My boards came from thonk and my switches came from Tayda. Fits great on the combined panel but too narrow for my extra input. Also, my direct input board fits AOk with its 3PDT switch 
Sorry missed this until now!
Looks like the Tayda switches have a 6.35mm mounting diameter. Sometimes there are slight tolerance issues with JLCPCB so it might be a tight fit… or even not a fit: some modules I made the panels had smaller holes because I built my units using switches from elsewhere (Mouser?) which I think were slightly smaller than Tayda. But it was a while ago sorry, I’m not completely sure.
Personally I use a small chainsaw blade sharpening file to widen holes on PCBs/panels when I need to, because it’s conveniently sized and nicely rounded so the holes still end up with rounded sides. In the past on my panels I’ve had ground fills right up the holes to help keep out interference, but in the future I’m going to leave a bit of a gap so that there isn’t exposed copper plane that has to be filed away. Always another tweak required!
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@VisibleSignals Finally built the 1IF. Before I plug it in to test, just want to double-check that I connected the ground pins correctly (the build instructions weren’t 100% clear to me). Like this, right?..
Also, I put most of the components of the back board onto the opposite side from the labeled silkscreen. That seemed to make the most sense to me, to keep them out of the way of the power header. If that was your intended way for people to build it, might be good to mention that in the build guide, at the start. (And, indeed, might be good to label the parts on the other side of the board on any future revisions.)
Finally built the 1IF. Before I plug it in to test, just want to double-check that I connected the ground pins correctly (the build instructions weren’t 100% clear to me). Like this, right?..
Ground pin wiring is correct, well done!
Also, I put most of the components of the back board onto the opposite side from the labeled silkscreen. That seemed to make the most sense to me, to keep them out of the way of the power header. If that was your intended way for people to build it, might be good to mention that in the build guide, at the start. (And, indeed, might be good to label the parts on the other side of the board on any future revisions.)
For better or for worse (probably the latter) when I designed it I put the components on the same side as the power header, because I was worried there wouldn’t be enough room between the two boards for the components. Turns out there would have been enough room (except maybe for tall electrolytic capacitors)… but sadly it’s too late now 
So, you will run into trouble with how you’ve currently done it, because the op-amp power pins are effectively reversed when the op-amp is soldered on the opposite side. You MUST move the LM6172 to the same side (rear) as the power connector before you power it up. All the other components are fine soldered on that side though. If you have powered it up already then very likely the LM6172 will have been fried and will need to be replaced. Sorry to be the bearer of bad news
This is why I should ask questions before I solder things together! But I just felt like getting something done today, haha.
Luckily, I have indeed waited to power it up. Phew.
Downside, I guess, is that moving the IC (which of course I should’ve realized is the component where side of board really matters!) to the other side is going to be a bit of a trick on such a tiny, tight board. But I’ll muddle through, I reckon.
May be worth updating the build guide to say that putting components on other side is fine for all but IC. Good to spell things out in detail for folks like me who rush in (without fully thinking things through).
And, yeah, I usually use taller (cheaper) capacitors from Tayda when they fit, but had a few of the shorter ones spec’ed in LZX designs on hand.
Thanks!
Oof, yeah, not having much luck getting this IC off.
Desoldering smaller components isn’t that difficult. But something with this many feet and this tight a board… Looks like I’ve screwed myself a bit here. Realistically might not have the right tools for this. 99% sure I’ve already fried the chip with the amount of heat I’ve given it trying to make this happen. Not too big a deal since I actually have a ton of LM6172s lying around. But looks like I might need to remove some of the surrounding components too and will need to first reacquire a few of the less common resistor values of which I don’t seem to have any spares.
I don’t know, unless anyone has any hot tips for desoldering ICs.
ICs can be very hard to desolder. try to heat several pins at a time (with added flux) and put some force underneath the IC to pull one side up. then continue with the other side.
If that fails:
a destructive method would be to cut off the legs, then desolder the remaining pins.
and if that fails, you can fill the holes with solder blobs and place the new lm6172 on top of that (or use a socket) and reheat the blobs .
All what matters in the end is that the pins make a good connection to the board.
just wanted to add to the desoldering advice:
- doing this with a hot air station would be the best approach - if you have access to someone with one, or maybe a shared hackspace etc they likely have one already - alternatively they can be picked up for quite cheap - im still on a 30euro one i got maybe 4 years ago… just remove as much solder with braid as you can first - then hold the ic with tweezers in one hand and heat the pins of the ic with other until it just comes loose
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Agreed, it’s not easy. TBH chips can take a surprising amount of heat, but yes they do have a limit.
My technique when I used to do tool-less desoldering was to run the soldering iron back and forth along well-lubed (with solder) pins on one side, while simultaneously trying to use a small flat screwdriver to lever up that side of the chip. Once it is levered nearly (but not all) the way up, swap over and do the other row of pins. Then repeat with complete pin removal, one side at a time. It’s incredibly awkward and difficult and the success is absolutely not guaranteed. It took a lot of practice.
One helpful tip I can give you is to look up “8pcs Hollow Needles Desoldering Tool IC Extraction Tool Set” or similar because they are pretty helpful in certain circumstances (especially useful when cleaning out the pin holes before you solder in a new chip).
A chip removal tool (like pliers but with little handles on each end, to lever under the chips) is a handy thing to have as well.
If you’re super-lucky your soldering iron model might support copper-block tips which can melt the solder of all DIP chip pins at once, but those are rare as hen’s teeth. I only have a DIP16 so it’s often too big for DIP8.
Your best bet is absolutely a hot air rework station, but the decent ones tend to be quite expensive On the plus side, once you have one you can recover endless components from old electronics and save! I have a very large pile of e-waste I work through on cold nights
While I’m here providing random advice, check out Peper’s Pedal’s “Rocket Sockets”. They are just the best!
And the lateral fans from really chunky old printers are great for keeping the fumes away when you’re soldering - especially if you’re harvesting components from e-waste and the solder they used smells REALLY funky :-o
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