AMZ Overdrive pro up and running. Now for some possible mods....

[Xavier]

I have just built this effect, after some debugging (actually the first time I have debugged a pedal instead of calling it a day )

Now, it has tons of gain that's for sure, and the eq is really useful. I have used LED's for the clipping section after reading all the answers complaining about the "lack" of output. I would say it's more of a distortion than an overdrive.

I have an issue though. When you hit a string hard, there's some kind of ugly saturation in the high frequencies, like when you play too loud with a SS amp clean channel, kind of a digital clip if that makes some sense...

My only mod question is: how could I reduce the bass into the clipping section? I'd like a tighter sounding distortion. Now it reminds me a little bit to the DS1 kind of sound, where you have this (to me) excessive mid-bass frequencies adding some mush to the tone...

Other than this, a really versatile dist pedal !!!

[tungngruv]

Here is what Jack says on his site:

Use a bipolar opamp for IC1, even the LM741 will sound good!
If it is too fizzy sounding, increase C5 to 270pF or 560pF
For more bass response, increase C4 to 2.2uF or 4.7uF
Use red LEDs for D1 and D2 for more output
The tone control shown on the schematic has a big mid-range scoop. If you would like a more traditional response, increase C8 to 470pF or even 1000pF

And Tonepad.com has this:

Jack suggests that R2 and R4 can be changed to 240k and 1.5k respectively.

Maybe try switching C4 with a smaller value? Mine doesn't seem to have that issue but I'm using a tube amp.

[Xavier]

I saw the mods proposed by Jack, but none of them seems to be related to my issue. I don't think it's fizzy sounding nor it needs more bass, it sounds great as it is. I'm not sure whether I should change R8-C6 values or R6-C4. I never modified a diodes-to-ground dist before...

[stumper1]

To tighten things up a bit - lower the value of the input cap (not sure what number on the schematic as it's not in front of me).  I believe the stock value was 1uf.  I started at .0022uf and worked my up from there.  Don't recall off hand where I ended up but I think it was between .0068 and .01.

This definately took the mud out of the low end.

I used LEDs at first also but after trying it with diodes I liked the sound much better.  RDV posted a schem for a Gain Recovery stage using the second half of the dual op-amp that worked perfect!

Good Luck!!

[Xavier]

To tighten things up a bit - lower the value of the input cap (not sure what number on the schematic as it's not in front of me).  I believe the stock value was 1uf.  I started at .0022uf and worked my up from there.  Don't recall off hand where I ended up but I think it was between .0068 and .01.

This definately took the mud out of the low end.

I used LEDs at first also but after trying it with diodes I liked the sound much better.  RDV posted a schem for a Gain Recovery stage using the second half of the dual op-amp that worked perfect!

Good Luck!!

Thanks A LOT stumper1..... definitely I'll try changing the input cap and the diodes. So I'm not the only one with this issue........