Here's my situation:

I'm the singer for my band and I want to add effects (reverb particularly) to my voice.
We've been practicing by running our mic through an electric amp, which sounds obviously off, but not quite bad.

My question is this - would it sound better if we plugged our mic into the amp, used the built-in effects of the amp to add reverb and then plug the amp output into our PA?

The idea is to bypass the amp's speaker - would it make any difference in quality?
This actually works better with an acoustic amp. Most of them are sold as stereo and are marketed for this purpose. The reason being, is an acoustic amp covers a wider frequency range. Electric guitar amps typically use woofers, so there's not much in the way of mids and highs. Using a different speaker might help. It just all depends on how the amp is designed. If it's attenuating the mids and highs, it won't matter.

Edit: Just finished reading the rest of your question. Whatever you do, DO NOT plug the output of your guitar amp into a PA. You'll blow up the amp AND the PA. Mic the guitar amp, just like you're playing a guitar through it. Now, if your amp has a special low level line out, like some do, then it's fine to plug that directly into the PA. Just don't connect the speaker output into the PA.
Last edited by KG6_Steven at Sep 16, 2010,
I hope your amp output is line level (i.e. not cab output), otherwise you're going to have some interesting charred electronic equipment.

Assuming it is, it's a pretty mediocre to bad idea anyway. The parametric EQ on most guitar amps is voiced for guitar, which means it cuts the really high end treble you usually have on a totally clean power amplifier. In other words, it'll sound nasal, muffled and generally bad.

Look into getting a cheap keyboard or bass amplifier for voice, they are much more forgiving on EQ range and the speaker handles the frequencies better too. As for effects, most Keyboard amps come with reverb. any other vocal effects would be better as specifically vocal stompboxes than jury-rigging onboard guitar effects into the signal path.
I once did a similar thing with a small multi-purpose amp (sent vocals and guitar into it for reverb etc. then took a line out into the PA) and it worked great- did several gigs to over 200 people with it.
Gibson Les Paul Standard 2004
Fender Telecaster Custom 72RI 2009
Ashdown Fallen Angel 60DSP
Fender Blues Junior
Ashton MPA100
You'll be using the preamp of the amp as well as the reverb so it won't sound that good really. And you wouldn't want to go from the amp's output, you'd want to go from the effects send if it had one. The output has too high an output, you'd be hard pushed to get the volume low enough to not distort the crap out of the PA's channel. You could even blow it up.
You'd be better off looking on ebay for a cheap reverb unit you can hook up to your PA. I picked up an Alesis Picoverb on US Ebay for $20 - that would be a far better solution.

Keep your eye on this:
Or just use the buy now, it's only $50
Gilchrist custom
Yamaha SBG500
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100

Cathbard Amplification
My band
Last edited by Cathbard at Sep 17, 2010,
alright thanks for the replies guys. Yeah, I was only going to use the line output. I dunno what I will end up doing, maybe just foregoing the reverb for now. We are on a tight college-band budget
just try it and see what it sounds like?
Gibson Les Paul Standard 2004
Fender Telecaster Custom 72RI 2009
Ashdown Fallen Angel 60DSP
Fender Blues Junior
Ashton MPA100