i need an opamp suggestion

I'm sorry I forgot to add... that I'm trying to do this with only a positive rail and ground, is there a good single supply opamp for this?

LM324 quad, TL081 single/082 dual/084 quad.

GOod Luck! Rich

... a gain ofbetween 10-100... maybe 500 at most....

That means the gain-bandwidth product is 10 MHz; you will want to cascade two garden-variety amplifiers (each with max gain of 22). TL072 is a suitable dual op amp for audio. Connect the midpoint of your 9V battery to your ground, so it makes a +/- 4.5V supply.

The TL072 has a GBW of just 3Mhz. A LM833 or NE5534 will do the job.

So... in order to use an opamp with a guitar signal (or audio signal) I will need to power one of the rails with a negative voltage... is this right? If I have one of the rails at ground, does that mean that I can't go lower than that with my output?

thanks

My intention was not to get the full gain with a single amplifier stage; two stages of amplification (22 being the square root of 500) means that neither stage needs get near the gain-bandwidth limit.

It's not a necessity, the signal can either go through a DC blocking capacitor OR the power supply can be ground-referenced at midpoint. It's easier to do to the power supply, though.

Not lower if your output is directly coupled to the operational amplifier; it'd take a transformer or capacitor, with some associated low-frequency rolloff. You need some low-frequency DC rejection in any case, with a gain as high as 500 volts out per volt in, but it can be a small capacitor that isn't signal-critical.

Why do you want to boost your signal that much? A guitar poickup's ouput is in the 100mV - 1V range. I don't think you want it to be 50V do you?

I've had good luck with a TL072 (dual) or TL071 (single) for boosting guitar signals. You don't need a dual supply, you just need to bias the input at

What exactly are you trying to do?