Can a regular stereo amp be used for guitar?

[Enzo]

My first guitar amp was a Webcor tape recorder, like we used in grade school classes. We had to put it into record, stick a piece of cardboard into the tape sensor so it didn't default to STOP. A 5x9 speaker. I don't know, a couple watts, no more than five surely. I played BASS through that.

If all you want is for guitar sound to come out a speaker, then a stereo amp can do that. But it won't have much tone. It is simply the wrong tool for the job.

Can you mow the lawn with a hedge trimmer? Yes. Is it a good way to do it? No.

[Leo_Gnardo]

Most hifi amps have input impedances around 50k. Most pickups sound best at input impedances of 500k or greater. So it may be a good idea to use a buffer or buffered pedal like e.g. a Tubescreamer in front of the stereo amp. The signal at the pedal's low impedance output can be easily split to drive both channes.

That right there ^^ is another factor. Loading a guitar with less than optimum impedance results in a naff tone every time.

Your suggestion of a buffered FX pedal is spot on. Other suggestions, maybe one of those modeling preamps by Zoom. Line 6/Pod, Tech21 or similar. Any would offer a selection of tones and effects.

mikepukmel, I cannot resist an opportunity to post another photo of the ol' Wall of Sound. Those were the days! Bring 'em back! Difficult to deal with, but an unbeatable sound quality.

[mikepukmel]

My first guitar amp was a Webcor tape recorder, like we used in grade school classes. We had to put it into record, stick a piece of cardboard into the tape sensor so it didn't default to STOP. A 5x9 speaker. I don't know, a couple watts, no more than five surely. I played BASS through that.

If all you want is for guitar sound to come out a speaker, then a stereo amp can do that. But it won't have much tone. It is simply the wrong tool for the job.

Can you mow the lawn with a hedge trimmer? Yes. Is it a good way to do it? No.

Similar story. I tried to hook up a guitar to an old RCA (I think it was RCA) stereo/radio vacuum tube console. Sounded HI-DE-OUS, even to my tin ear. Way too much high frequency, and didn't sound like a guitar.

[The Dude]

......She has a GSP21 sound modeler......

You have what is basically a guitar preamp there. I see no reason you couldn't use the Onkyo with that. The way you initially posed the question led us to believe that you were going to plug the guitar directly into the Onkyo somehow.

[Chuck H]

You have what is basically a guitar preamp there. I see no reason you couldn't use the Onkyo with that.

True enough. The signal processor and guitar speaker cabinet will handle the tone in this case. Unless the Onkyo's channels are bridgeable you're still limited to only using one channel. The Onkyo is a decent quality home stereo amp and could be used as such by someone who needs it. Trade/partial trade it for a guitar amp that will offer more useful features overall. That's still my vote.

[Enzo]

I'd be really surprised if the Onkyo didn't have a MONO button, that would feed both channels.

[Dave H]

I'd be really surprised if the Onkyo didn't have a MONO button, that would feed both channels.

I thought of that but then you'd need two speakers.

[g1]

How about just use the left & right outs of the GSP21 ?

[Leo_Gnardo]

How about just use the left & right outs of the GSP21 ?

I was gonna say... And though it's sort of an oldie but goodie, it IS a good sounding processor. Pick left OR right and twang away. Or get another speaker cab and experience the Magic of Stereo. Whatever - but don't combine the Onkyo's outputs thinking you're going to get more power. Or something. The something you will get is a smoking hulk. Drive separate speakers with each amp channel please!

[g1]

And apologies to syzygyn, post #12 must have been held up in the moderation queue. It showed up after post #13 & #15, which now don't make much sense.

[Leo_Gnardo]

And apologies to syzygyn, post #12 must have been held up in the moderation queue. It showed up after post #13 & #15, which now don't make much sense.

Thanks! I was worried my mind was playing tricks on me. Given the real order of arrival, the suggestions are sensible.

[olddawg]

Honestly... an SS power amp is an SS power amp. The big difference is in the preamp and the speakers. If she is using a “guitar” speaker cabinet and plugs a modeler pedal or some other guitar preamp with a line level signal into the “tape monitor input” or “main amp” input, there will be little difference than using a rack power amp of the same power rating. Also.. people plug “direct in” in the studio and in home recording all of the time or even direct into a PA. The Onkyo just doesn’t have the correct preamp architecture for guitar. No “guitar” input. At low volume with a modeler it would probably sound fine through the Okyo speakers. No different than DI in studio.

[syzygyn]

Thanks for all the help. I think I lost a post in the moderation but the amp works with the GSP21 in front of it. I have another question about how to feed MIDI drums into the GSP21. Maybe another topic?

[Guitarist]

Yes, a modeler direct I is a good way to go. You can make a custom cable if you're trying to play two things at once (sharing a Tape Input). Just add 6.8K or 10KΩ resistors in series of the + of all four channels. This is a passive mixer isolating the signals.

[qweiczz]

One could take the Onkyo to the nearest pawn shop and trade or partial trade it for a proper guitar amp.