The Aefea Drive - a simple one-chip diversion

[cab42]

Thanks, Mark. I was thinking along those Lines, that the extra diodes did not contribute much. But I must admit that I missed that the rat did not have any diodes in the feedback loop  when looking at the schematic so your suggestions makes a lot of sense.

I think I will try a switch that switches out the feedback diodes and switches in the diodes to Ground.

I could also just build a rat 

[Mark Hammer]

Given that some of the magic of a Rat comes from the use of an externally compensated LM308, and much less comes from the use of diodes to ground, making a Rat might not be such a bad idea.  On the other hand you could use the diode switch to contrast between asymmetrical clipping (stock) and symmetrical hard clipping.  Might sound different.  Might be appealing to you.  You never know until you try.

[bool]

Leds in opamp nfb running into silicon diodes-to-ground clipper is a time-tested combination.

[Ben N]

Leds in opamp nfb running into silicon diodes-to-ground clipper is a time-tested combination.

So that by the time the hard clipping, high threshold LEDs kick in, you're already well up into the gain range of the pedal, and then you get that little extra bit of limiting?

[bool]

That "little bit extra" depends on how much "gain" you dial-in. Mainly, it's a different method of hard-clipping, and it gives a bit more consistency compared to running a opamp into rails (which depends on exact rail voltage - meaning the circuit will work different if your battery is low or if it is brand new ...).