Where does the "voice" of an overdrive come from... ?

[e_man_89]

Is it the op amp? the circuit? a little of both?

I wonder how important the op amp choice is to the end result of the overdrive...

 

[wintercept]

With few exceptions, opamp choice matters less for tone shaping than most people would like to believe.

Chips in the old block

I did a search to see if there were any threads dealing with the use of alternate op amps in the OD/Dist/Fuzz category and didn't find anything. Is there a discussion to be had here from the experienced builders? I know if you're using a dual op amp you've got to sub another dualie, but what...

forum.pedalpcb.com

This thread has some pretty good info on the subject.

In short, the circuit built around the active device (opamp, transistor, etc.) is responsible for the tone shaping. For example, a Tube Screamer has a simple high pass filter as one of the main elements contributing to its very mid focused sound. Similarly, the values of a stock Big Muff tone control circuit result in the infamous scoop.

 

[e_man_89]

Thanks wintercept, I've read behind a number of people that feel this way. There is very likely some measurable differences, but it's what I can hear that matters.

This question came out of the idea of changing the op amp in my Blue Breaker just to see if there is a difference, (particularly in volume).

It has a TL072 in it now. I've got a 4558, LM358, and a TL082 on hand.

Might test drive these...

 

[spi]

Might test drive these...

that's the best way to find out!

Let us know the results.

 

[e_man_89]

10:4

 

[wintercept]

Yes if you have them on hand, definitely test them out. Experimenting and finding what you like the best is what it’s all about.