What am I doing wrong? (Clean blend and hiss)

[Boba7]

And you did it at pcb? If you have only prototype at breadboard, then I must warn - breadboard always add big noise to signal!

Yes I used a pcb directly, thinking it would be fine!

[Zerro]

So, finally, if nothing will help (controll or exchange those caps and resistors), try super low-noise opamp: RC4580. If nothing changes in compare even with common standard-noise opamps here, it is clear that you must order better quality res and caps. Nothing bad. Concept is good. Only details will ask more.

[Boba7]

So, finally, if nothing will help (controll or exchange those caps and resistors), try super low-noise opamp: RC4580. If nothing changes in compare even with common standard-noise opamps here, it is clear that you must order better quality res and caps. Nothing bad. Concept is good. Only details will ask more.

Thanks! Ill try a 4580, I think I have some in my drawer.
Otherwise yes I could try and change the caps, I've used mostly mlcc on this board. But Ive never had issues with them so far... resistors are pretty standard 1%.

[Zerro]

ok. Try that 4580 and compare with common opamp, like 1458, 358 or 082...

[Boba7]

ok. Try that 4580 and compare with common opamp, like 1458, 358 or 082...

4580 doesn't make any difference.
Maybe the noise is acceptable... But I just dont like it

So I'm gonna try this instead. Two opamps so a bit more space needed, but that way I'm pretty sure the clean signal is gonna stay clean, with no added noise whatsoever. And I'm sending an inverted signal to the overdrive (that reverses the signal) then returning it through a buffer. It should be clean!
Clean pot is 100kB.

(I'm pretty sure I could get rid of C7 and R14, I'll have to check)

[Zerro]

That first model seemed to me better. Minimally you could put paralelly with gain pot 50k some little cap (470pF best) to minimize HF hiss. And serially some res cca 1kOhm. BTW many noises do sockets - at the end it is only mechanical contact! I suppose you put those opamps directly to the pcb desk?

[Boba7]

Yes I already replaced the 100p in parallel with the gain pot (50k) with a 470p. It made a difference, but not enough. Larger values cut too much high end.
I don't think a series resistance with the gain pot would make a difference in noise...
The opamp is on a socket yes, but I've never had any issue with sockets!

I think my second version is not very elegant but I trust it to be less noisy (only buffers, no gain stage)

[Zerro]

That serial res I recomended not to have clear wire here, when pot is at minimum :@)
I am really wonder how that second version will work.

BTW, with Gain pot at max. 50kOhm and paralelly 470pF cap, lowpass will have knee at 6,8kHz. For most gui FX top freq at EQ settings is 6,4kHz. That cap is ideal with that gain pot.

[Boba7]

That serial res I recomended not to have clear wire here, when pot is at minimum :@)
I am really wonder how that second version will work.

BTW, with Gain pot at max. 50kOhm and paralelly 470pF cap, lowpass will have knee at 6,8kHz. For most gui FX top freq at EQ settings is 6,4kHz. That cap is ideal with that gain pot.

Hey thanks a lot for all your help and your patience! Its really great!
I'll let you know how it works! It's not gonna be before a few weeks I think (I have other projects too... and work... and a family... ) but I will let you know for sure.

[Zerro]

Ok, I will be wonder for it! Z