Using a mic with a guitar amp?

[MrDaner]

Can a mic be plugged into a guitar amp so that I can sing and play? If possible I would look at something with 'practise amp' type volume. I will only play at home and occasionally play along with a friend who has an accoustic.

If it's possible, is there only certain types of amps that can do this? What should I look for? Any recommendations?

[mhammer]

That is, in fact, how a great many bands worked in the old days. I know my band played a wedding at a country club that way.

Whle you CAN plug some mics directly into an amp, it is no guarantee of success whatsoever (we couldn't tell the difference in the old days).

First, the impedance of the mic and the guitar are fundamentally different beasts about 98% of the time. So, you will not get the full frequency range of the mic unless something goes in between the mic and amp.

Second, the output levels of the mic and guitar are worlds apart. Not only will this make it difficult to have a guitar level and mic level you can live with (should you plug them in at once), but the S/N specs for the mic will be simply unacceptable when you plug a mic directly into the amp. The amp does not have balanced inputs so if there is any tendency to pick up hum along the way, the amp will need to be turned up loud enough to make the mic audible that the hum and hiss will be VERY noticeable.

Third, guitar amps are made to break up easily, which may not suit the voice mic application at all.

The simplest thing is to comb the used gear places and pick yourself up a simple mic preamp for $50 or so. That will do al the requisite buffering, balanced to unbalanced conversion, and add enough gain to the mic signal that it can go into the amp and be given the respect it deserves.

[Paul]

Many tweed Fender amps from the 50's had inputs labled "mic" and "inst"....so what do you think?

I don't even use a pre-amp on the occasions I've used my guitar amp for vocal work. I get acceptable enough performance just using an impedance matching transformer. You can even get mic cables with these built into 'em.

You will have much better success if the guitar amp you are using has two channels, such as a Twin Reverb. Sometimes plugging into both the high and low inputs on the same channel will give less than desirable results.