5E3 as acoustic / vocal amp

[elpops]

I can imagine that the 5E3 might not be the ideal acoustic guitar / vocal microphone amplifier, but can it pass? No doubt it has been used for this purpose at some point in the last 50 years? I have a 5E3 clone that has an OT that will support 6V6 or 6L6 tubes--maybe the tighter midrange and higher headroom of the 6L6's will help it some? I ask because the thought of buying or building another amp for acoustic performance just kills me. Plus, if I already have an acoustic guitar preamp, I ought to be able to shape the tone somewhat before it even gets to the amp, right?

What do you think--it is a lost cause? Is there anything I can do to mod the circuit to make it more conducive to this application (without ruining it as an electric guitar amp?)

Thanks!

ElPops

[Satamax]

Just buy yourself an old valve PA and mod according to taste!

[MWJB]

...or a tolex twin? I've sung through an SF twin in small to medium rooms, no worries.

Back to the 5E3...

How big a room are you going to be playing in? It might just possibly be feasible in a very small room. I've seen a guy sing through a little Park amp a couple of times, in a small bar. It did the job. If the audience get noisy you will be scuppered.

A couple of points to consider...

Whether you use a preamp or not, it's what happens to your signal once it's in the 5E3's preamp that's more the issue.

Any mods to make the amp more suitable for an acoustic instrument, or mic, will obviously change the sound for electric guitar.

The 6L6 power tubes on their own aren't going to make the amp any louder with the mic, over the 6V6's - but give them a go anyway, dynamics may improve a little.

In the first instance I'd be looking to reduce gain & coloration by removing the 25uf bypass cap from V2...have a listen, then maybe try removing the V1 cathode bypass cap too? With both removed the amp will probably sound awful for electric guitar but they're easy enough to put back/switch in/out.

Bruce Collins' Vol/tone mod will give you a more useable sweep on the volume when using a mic. You could also add a resistor between wiper & ground on the mic channel volume to tame that further if necessary? Use a regular Lo-Z PA mic with a lo-Z to hi-Z, in-line mic transformer, plug it into a low gain input.

Even if your expectations are realistic, you still may be asking for a lot.

[Ampclutz]

Didn't the origional 5E3 have one of the channel inputs labeled "Mic"? That should tell you something about its usefulness as a mic amp. I forget which channel it was...

You could just plug into the "Mic" channel and give it a try. Nothing to lose is there?

AC

[Thorny]

will work in a pinch

yeah, they had a channel labeled "mic". A buddy of mine bought a tweed deluxe from an old auctioneer. I don't think you it'l make you throw away you a real PA, but it may do in a pinch if you don't have overly high sound expectations.

[clyde]

mic input

I think it would be what is nowadays called the normal input. Not sure as to which input to use. Probably depends on the mic you are using.

[Arthur B.]

The biggest issue I can think of is the concertina PI. It has poor headroom and is expected to go through large signal swings. If you have the space, add another tube socket for a couple gain stages after the concertina.

[MWJB]

Adding gain will increase feedback dramatically and completely negate this particular (already hot) amps limited usefulness with a mic.

[Arthur B.]

Adding gain will increase feedback dramatically and completely negate this particular (already hot) amps limited usefulness with a mic.

How will adding gain stages after the concertina increase feedback?

[MWJB]

Because you are increasing gain. Amps that work well with mics usually have relatively few gain stages. When using a mic with an amp, the main factor you work have to work round is usually defeating acoustic feedback, which, with a solid body guitar & magnetic pick ups, is rarely an issue.

The 5E3 already has a lot of preamp gain and, due to the fast ramping up on the stock volume pot configuration, it's suitability for use with a mic is relatively limited. Adding extra gain stages, rather than reducing gain, will shut you down with feedback earlier, reducing volume available.

I have an amp with a gain stage after the concertina so I know this from experience.

[Arthur B.]

Because you are increasing gain. Amps that work well with mics usually have relatively few gain stages. When using a mic with an amp, the main factor you work have to work round is usually defeating acoustic feedback, which, with a solid body guitar & magnetic pick ups, is rarely an issue.

The 5E3 already has a lot of preamp gain and, due to the fast ramping up on the stock volume pot configuration, it's suitability for use with a mic is relatively limited. Adding extra gain stages, rather than reducing gain, will shut you down with feedback earlier, reducing volume available.

I have an amp with a gain stage after the concertina so I know this from experience.

Ok, I get it. I was thinking of NFB, and you were talking bout PFB. If the preamp has too much gain, why not reduce it by removing the bypass capacitors?

[MWJB]

Yes, that's one effective course of action.

[petemoore]

But it won't be a workhorse.
I see no problem using the 5e3 to get good sounding vocals, reasonably wide frequency response, very limited PA type features.
{Quote}...or a tolex twin? I've sung through an SF twin in small to medium rooms}
I have recordings my one brother made of my other brothers band, a Twin Reverb was pressed into service 1967, used as Mic and Guitar Amplification system, it did a marvelous job.
I plugged an EV757 or SM57 in>5e3>2x12'' greenbacks 'light'/oversize cab...here's what I noticed.
Frequency range is fine for me, not exactly 'extended' [fine w/me] especially at low volume.
Limited' features for 'PA', I'd call it a 'Vocal Amp', w/main feature: it'll 'tube distort easy'.
Turning up the volume changes...everything...
I'd need to have an EQ to do more 'Mic-Distorting' testing, the bass just took over too much. Getting the mic farther away would help, distortion = early onset of feedback...the same properties what makes a guitar sustain at lower volumes .distortion/feedback. makes a mic squeal real easy.
Needed more highs, like a nice passive Xover and a horn.
As far as the amp itself, it'll 'do' clean and will distort easy enough/too easy.
For anything except extending the frequency range [just about any mic/system'll do that] at low-ish volumes, I would opt for something more powerful and well featured...ie the 5e3 sounds good/great, you just can't crank it much because that changes the frequency response, Volume, and Distortion levels at once.