Alternative PCB for Pythagoras circuit at PCBWay.com

Paul.Ruby

Well-known member
I screwed up the thread title. Meant to say "... at PCBWay.com"

In order to embed reverb into a combo pedal, I've made a PCB in small format. My intent is to install an always-on reverb into a combo pedal and use trim pots to "set it and forget it." Here's one with alpha pots used for testing. It's almost identical to the Pythagoras with some minor exceptions. The LED is hooked to the clipping indicator from the FV-1. The output capacitor is increased to 2.2uf as I was getting some low end loss. I used SMD chips since I had to solder the FV-1 anyway. Easy to do on a hot plate with some solder paste on the pads.
P1020331.JPG

Eeprom and jumpers on the back for easy access. (I know the flux needs some clean up.)
P1020332.JPG
Interactive BOM:

PCBWay link to the project (might not be live yet). I have a few left if anyone wants a PCB in the US. I will likely only use 5 of the 10 ordered. There is a BOM at this link as well with mouser links to all the parts. The links to POTs point to 12-turn trimmer pots that will fit but the footprint is for alpha 9mm vertical pots.
 
FYI... The board is 2.5x1.75". I squeezed the one above into a 1590G but it was very tight on the sides to fit the jacks and I had to cut a hole in the base plate for the jumpers and eeprom to stick through a bit (but it gives me access to them easily). This case is only 1" tall. If you leave out the eeprom and jumpers to just pick an internal program then it fits fine in the 1" height. The 1590G2 is 1.3" tall, which would be better and it's probably the smallest case that can be used for a stand-alone unit with the jumpers and eeprom on the back.

Of course, the real purpose of this is as one module in a larger combo pedal case like I've done here:
 
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Had to make some tweaks to mine for signal levels. The clipping LED was on all the time, so signal was too hot into the FV-1. And then the signal out of the FV1 was hot and hard to only add a small amount of reverb. These changes might be needed for others. First get input signal adjusted to avoid hard clipping. Then further reduce output signal if it's still too hot to mix into the output signal.
1719939663777.png
 
I just found this little coded rotary switch on mouser and ordered some. Also tweaked my PCB design to use it and need an excuse to order a batch. Is anyone interested? I've already built enough of the original boards that I don't need them with a rotary. But, it's so cheap to order 10...

UPDATE: I must have a serious problem... Ordered 10 PCBs from PCBWay... And 10 more FV1. I need counseling. :)

Another UPDATE. The correct rotary for pythagoras is this one (the "real code" version) but I ordered the "complementary code" version above. So, mine are going to have the numbering reversed. 0 will be 7, 1 will be 6, etc... Duh.
 
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