The off-board wiring's not the most intuitive, so here's a diagram for wiring up the buffer switch and 3PDT bypass footswitch.
Thursday, July 18, 2019
Fulltone OCD V2
The latest iteration of the OCD has quite a few differences from the earlier models. There's an added transistor stage at the output after the volume control, and a JFET buffer that can be toggled for buffered or true bypass. I've laid it out so it will still fit in a 1590B with board mounted pots.
https://www.youtube.com/watch?v=h3uBr0CCm58
ReplyDeleteSchematic?
ReplyDeletehttps://www.pedalpcb.com/docs/ADHD.pdf
DeleteWhen looking at the On Semiconductor datasheet I think you need to rotate the 2N5457 180 degrees. So always check your transistor pinout before soldering :)
ReplyDeleteYeah you're right. Must have gotten turned around. I'll fix the image.
DeleteFixed
DeleteThank you great, David!
ReplyDeleteChecked! Sounds beautifully, it took a little work to finish, many wires to solder, I made a small change to be able to switch between clipping the 2n7000 and some red LEDs, there is a small change in the sound but I still don't know if it's worth it. Thanks for more this great layout!
ReplyDeleteAwesome! Thanks for verifying!
DeleteI have slight overdrive, when i use buffer. Without (direct) buffer - clear signal. Is anybody have same problem? Used 2n5457 transistors.
ReplyDeleteYes, same problem here. I tried some 2n5458, and J201 it is working little bit better (louder). On true bypass there is no problem. Will try some SMD versions of 2n5457... think, i might have some "fake" out of specs 2n5457...
DeleteI just try mmbf5457 on adapter, works perfect with them... no volume loss at all on buffered mod... just pickup up some good 2n5457 or SMD version... ;-)
Deletehi everyone, i did this great pedal and it works well but I feel it needs a little more definition in the high end, sharpen the sound a little bit. Do you think this could be due to bad 2N5457 ICs ? thanks.
ReplyDeleteNot likely to be semiconductors. You may just need to adjust some cap values to taste.
DeleteVerified, and built it with a switch to switch between V2 and the Custom GE Version. Is it correct that unity is somewhere between 12 and 1?
ReplyDelete