simple circuit to convert guitar signal to CLEAN line level or vice versa???

[loss1234]

I am sure this is an easy question but i am running out of time.

I am looking for a one or two opamp circuit that will Boost my guitar signal enough so that it can compete with AND mix in with things like synths, drum machines,etc. (synths are usually 5 or 10 volts peak to peak)
I am NOT looking for anything that will add overdrive or distortion. just good clean volume (with a gain control)

or on the flipside, an easy circuit to reduce the level of a line signal so that it can plug straight into my stompboxes or amp.



thanks so much

[R.G.]

Guitar level is a variable. Low output single coils put out maybe 80-100mV peak, high output humbuckers can put out a volt or so.

Line level comes in two flavors, consumer line level and pro audio line level. Consumer is 775mVrms as I remember, pro audio is something like 1Vrms (1.414V peak)

Making line level out of guitar, you'll need about a gain or ten (20db) available, but the ability to vary it downwards for high output pickups. A 9V battery gets marginal for this, expecially the pick attack transient that can be 2-3x the signals I just quoted; so for a good job, you'd need to run with two batteries or a charge pump to make yourself +/-9V. You might get by without that for a single coil and keep it clean.

It's easier going back the other way. Just use a resistor divider to pad it down. A nominal 10:1 divider would work fine in most cases. Something like 9.1K and 1K. You could also use a 5K resistor and a 5K pot to ground. That would let you adjust levels. It's much easier and cheaper to divide down than amplify up.

Some synths output 5V peak or even 10V peak, so you'd need even more division. The pot version would do it OK, but you'll need to be careful about the settings on the pot.