Typical pre-amps found in quality valve amps have rails of 400V and two cascade input stages of Av=50 followed by another Av=50, letting the valves do the smooth clipping. You have to account for clipping and make the clipping as symmetrical as possible and as smooth as possible. You cannot do it with 5V, or with 30V (2x15V). But then guitar pickup amps have a ridiculous ceiling, and any amp will clip, unless you have equally ridiculous voltage rails.

I would use a 500K instead, it is very common. I believe the 1M resistor is too high and just asking for noise and offsets. As was noted right at the start, a 47K bias resistor would steal all the high frequencies - it would sound *exactly* like when you plug your guitar into your stereo system, it really does not sound like a guitar at all. I have looked quickly and maybe I am making a mistake, but can I just say that an electric guitar requires a very specific equalisation with serious chopping down the mids and amplifying the highs (5KHz) just to get the usual, clean sound. Next is the circuit board layout and enclosure making. Calexanian, I am curious about the other circuits you have used/come across for this purpose as you mentioned there are other circuits, what are they? Thanks again, I think it's finally coming together. This opamp worked great as far as I could tell, it was better than the TL082 I was using before at least. I also used an OPA4171 quad opamp package, mostly because I had a smd to dip convertor for it, while I didnвЂ™t have one for the OPA1664 that I was originally going to try. The output resistors have gone from 5ohms to 1ohm as per AudioguruвЂ™s suggestion, and the 10n capacitor across the output feedback loop is now gone. I tried a few different size capacitors and could not hear/see a difference between a pair of 1000uF caps and a pair of 220uF caps, so I stuck with the latter. I made the changes Hero999 suggested with the bypassing capacitors, and what a change! I am really impressed with how well it worked. This means that as the battery dies and the voltage begins to drop, the clip point will drop with it.

IвЂ™ve changed the clipping diodeвЂ™s reference to be two diode drops from the positive supply, rather than being referenced from ground, as suggested by Hero999.

Lm386 headphone amp schematic