Do any current preamp/boost pedals on the market use a dual op-amp circuit?

[circuit_learner_noob]

Getting something like that and putting a 4558 in it and taking the diodes out would be a good way to start!

Compare what we've been looking at with this. They're not so different:

https://buildyourownclone.com/products/lil-gray-od-kit

How would I solder an opamp to this PCB if the board only has connections/circuit wired for two diodes connected to ground?

[drdn0]

Getting something like that and putting a 4558 in it and taking the diodes out would be a good way to start!

Compare what we've been looking at with this. They're not so different:

https://buildyourownclone.com/products/lil-gray-od-kit

How would I solder an opamp to this PCB if the board only has connections/circuit wired for two diodes connected to ground?

I think you totally misunderstand what the op-amp is doing for clipping - it's not being used to replace diodes in a hard clipping arrangement. It's driven into clipping directly through signal amplification (which it can't keep up with) rather than cutting off input signal to ground.

Find any basic OD using an op-amp and clipping diodes. Remove the diodes entirely. Replace the op-amp - if it's a single, you may need to build an adapter on some sockets as the 4558 is a dual (which has a different pinout to a single). Done.

As an aside, I've built a FA1 and the gain stage itself will absolutely clip without any clipping diodes - I actually reduced the gain as I didn't like the overdrive flavour it gave. Arbitrarily 'worse' IC's like the 4558 or 1458 sound much better in this role than TL072's/NE5532's/etc (I'm guessing the lower slew rate helps). It very much did get that Edge-ish sound though

[ElectricDruid]

Arbitrarily 'worse' IC's like the 4558 or 1458 sound much better in this role than TL072's/NE5532's/etc (I'm guessing the lower slew rate helps).

I did some research into this at one point, because I needed an op-amp that could be guaranteed not to go into phase-reversal when clipping. Phase-reversal is when the input is trying to drive the ouput beyond where it can actually go, and instead of going further up, it starts going down instead (or vice versa at the negative supply). The TL072 is bad for that, but the 4558 is much more predictable and just clips calmly. So the slew rate is not the only reason, although that probably helps too.

[circuit_learner_noob]

I think you totally misunderstand what the op-amp is doing for clipping - it's not being used to replace diodes in a hard clipping arrangement. It's driven into clipping directly through signal amplification (which it can't keep up with) rather than cutting off input signal to ground.

Ahhh i see thanks for the clarification. I'll definitely try that out should be fun

[drdn0]

Arbitrarily 'worse' IC's like the 4558 or 1458 sound much better in this role than TL072's/NE5532's/etc (I'm guessing the lower slew rate helps).

I did some research into this at one point, because I needed an op-amp that could be guaranteed not to go into phase-reversal when clipping. Phase-reversal is when the input is trying to drive the ouput beyond where it can actually go, and instead of going further up, it starts going down instead (or vice versa at the negative supply). The TL072 is bad for that, but the 4558 is much more predictable and just clips calmly. So the slew rate is not the only reason, although that probably helps too.

I vaguely remember reading that the lower slew rate would help reduce higher frequency content due to clipping (and thereby uneven harmonics), but the phase reversal would absolutely make sense too.

I've basically just kept using older op-amps where they're likely to clip significantly and TL072/NE5532s where they're never going to clip (buffers, super low gain stages, etc). So far seems to work well, although I suspect if I started sanding the identifiers off the Toan might improve a little