building the best backline "house" amp

[yeahyeahyeah]

I've been asked to build an amp (approx. 50 watts) to keep onstage for anyone to use...

It needs to be able to work well with a variety of different guitars/pedals and will be used for many styles (but nothing too extreme)

It's really hard to do everything in one amp:confused:

My first thought was to build something fendery that has good cleans and takes pedals well. But what designs? blondes? blackface? twin, bassman, d'lux?

Any advice would be appreciated.
thanks.

[Backstage Kent]

I

It's really hard to do everything in one amp:confused:



No, it's impossible to do everything with one amp--that's why there's so many different kinds. Unless you're doing this for fun or out of the goodness of your heart, probably the venue should just buy something off the shelf, new, with a warranty--warrantees come in really handy for backline gear. A Hot Rod Deville probably comes as close as anything to being the "one size fits all" of amplifiers.

[SarasotaSlim]

Just wait - Mackie is gonna make it for you.

[hasserl]

Hot Rod Deville, Yuck! An amp to disappoint everyone equally, huh?

I think if you get one amp that does a good Fenderish tone and a decent Marshallish tone you've got it covered. A Bassman head with the Bass channel modified to mimic the 5F6A/JTM circuit should do fine. If you want to build from scratch, that's still the model I would use. Maybe go with AB763 on one channel, 5F6A on the other. Give it a 5F6A style PI and power amp. Reverb would be OK, but I wouldn't sweat it too much. If someone really wants verb have a Holy Grail handy for them. Maybe add an FX loop, but again,. I wouldn't sweat that too much. Keep the KISS principal foremost.

[yeahyeahyeah]

Hot Rod Deville, Yuck! An amp to disappoint everyone equally, huh?

I think if you get one amp that does a good Fenderish tone and a decent Marshallish tone you've got it covered. A Bassman head with the Bass channel modified to mimic the 5F6A/JTM circuit should do fine. If you want to build from scratch, that's still the model I would use. Maybe go with AB763 on one channel, 5F6A on the other. Give it a 5F6A style PI and power amp. Reverb would be OK, but I wouldn't sweat it too much. If someone really wants verb have a Holy Grail handy for them. Maybe add an FX loop, but again,. I wouldn't sweat that too much. Keep the KISS principal foremost.

Yeah, thats kind of what I was thinking of doing but I wasn't sure about the PI and Power amp values. Why would you use the Marshall PI instead of the Fender?

I'm not doing reverb but I'm going to put one of the ironsounds FX loops in there, because they are cheap, good and easy to install.

[hasserl]

Yeah, thats kind of what I was thinking of doing but I wasn't sure about the PI and Power amp values. Why would you use the Marshall PI instead of the Fender?

I'm not doing reverb but I'm going to put one of the ironsounds FX loops in there, because they are cheap, good and easy to install.

I say to use the Marshall style PI because a guy by the name of John Kelly Brown (Plexibreath on this bbs I think) created an amp a few years ago, he named The Transatlantic, that combined a Fender channel and a Marshall channel. He experimented with both PI's and found that the Fender channel responded well to both PI's, it really didn't care which one was used. But the Marshall channel responded much better to the Marshall PI than it did to the Fender PI. So he went with the Marshall PI.

I recently built an amp like this, building it into a Deluxe Reverb style chassis to be mounted into an old DR cabinet. AB763 on one side, 5F6A on the other, 5F6A PI, power amp and power supply. It worked great. Note that the AB763 channel, when not weighed down with Reverb and Trem kicks major ass! It actually had more gain than the 5F6A channel did. But my amp used a Bandmaster output tranny, because the guy that commissioned it had one and wanted me to use it. I would go with a Bassman OT, because IMO it is a great match for the Marshall channel. If you've heard a Bassman with the Bass channel modded to JTM circuit you know what I mean! They sound bitchin. Much better than the amp I built with the Bandmaster tranny.

[yeahyeahyeah]

Could you e-mail me the schematic you used?

[hasserl]

OK, check your email. That's the schematic I drew up for the project. It should be very close to the final amp, though I may have done some tweaking that I did not include, but I looked it over and it looks very close to me. Let me know if you have any questions.


Note my comment that you could leave the third gain stage off the AB763 channel and it would still be very cool without it. With the third gain stage it is a gain monster.

[PRNDL]

I think it depends on what you want:

Loud and clean ... Twin (4x6L6 with two 12" speakers)
Lower volume ... Deluxe (2x6L6 with one 12" speaker)
Easy to carry ... Princeton (2x6V6 with one 10" speaker)

[marshallnoise]

I second the bassman knock off. Preferably as a head and with an Avatar standard 2x12. Hellatone 60 and 30. I would do open back if its not going to be miced.

[John Phillips]

The answer already exists and is called a SF Twin Reverb :).

Anyone expecting a more fine-tuned tone than simple a good, solid clean out of a house amp is not very experienced at playing provided-backline gigs ;). You need to make sure all your tones come from your pedalboard.

If necessary, modify the Normal channel tone stack values to be closer to a Marshall. I would also consider putting Celestions (probably V30s) in it to further close the gap - that will have less effect on the tone of clean sounds than dirty BTW, and will make it work better with pedals.

I disagree with hasserl about the reverb, it is essential for some players and a Holy Grail is not the same thing (and also, they have a reputation for unreliability which is not what you want in a house amp).

If you're actually going to build it from scratch you could probably drop the tremolo (I like it, but I have a pedal anyway), but why bother? SF Twins are cheap and common, and all you need to do is fully overhaul it and maybe change a few values and there you are... bombproof reliability and a classic tone anyone shoud be familiar with.

[strumminsix]

IMO, a Mesa Lonestar Classic would fit the bill perfectly.

[Chris Scott]

I agree with John. A SF Twin is a cheap, user friendly and near-on bombproof tube guitar amp that everyone will be comfortable using, and an excellent pedal platform to boot. The back-dating of the bias circuit will enable you to use your choice of output tubes, but I reckon you knew that.......

So unless you are looking for work, I'd get one, service it and put it to work, and Bob's yer uncle.

(and Fanny's yer auntie)

[DAB]

I think one of the very best Fender Channel/Marshall Channel amps I have ever played or heard is the Rivera M60 or M100. Nice reverb as well. Master Volume. Gets nice Blackface cleans and Marshall grind and also takes pedals really well. Has a buffered effects loop. Anyway, this is a very versatile amp where you don't have to compromise on tone.

My .02

Dave