OT - Tube Amplifiers

[Outlaws]

I haven't played the Epiphone or the Pignose, but I have a ProJunior that is fairly cheap for a tube amp and is worth every penny IMO.

Definatly not an amp for surf or other super clean bell-like tonal music, but if you want something that will be both clean and still snarl with the best of them, its a good one to try out if you can.

[object88]

I don't recall the math, exactly, but 10x the power is about 2x as loud-- that's the logarithmic scale.  If you double the power, you get 3db more.  So, starting at 10W, you go to 20W (+3db), then to 40W (+6db), then to 80W (+9db), then a smidge more to 100W (~+10db).  10db is twice as loud, and you've got 10x the power.

However, even if you've got 10x the power and +10db, you've also got to think about the effeciency, size, and number of speakers.  If you hook up a 10W amp to a 4x12, I'd think it might give a 1x12 100W'er a decent run.  You also have to consider the style played through each amp.  If you're playing really clean through a 100W amp, you're little 10W'er will have a good chance of "catching up" by played heavily overdriven-- the overdrive will compress the sound, which gives "feels" like it's louder.

[Regan]

I wouldn't bother buying a newer amp to rebuild into something else, most are circuit board with cheap pots etc.
From what I have heard the mig amps sound decent and are close to a marshall but have very cheap pots and switches, so these would have to change.
Not sure where you live, but look for old tube organs or stereos at the thrift stores. Very cheap way to get parts.
Tube PA's like Bogen's, etc are a good starting point, they come with good transformers, pots, chassis etc.
The old standby, Traynor's, Garnet's, Standel's, etc. Sure the amp may cost you a couple of hundred, but they are built excellent and are perfect modifying platforms.
Regan

[AL]

Speakers are going to play a HUGE difference in the loudness (or percieved loudness). Yes, a 100 Watt amp will kill a 20 watt amp-if the 20 watt is running through a 10" speaker, which happens a lot. But put a 40 watt bassman through 4 x 10"'s and it will hold it's own nicely.

As far as rebuilding amps, everything I've been reading lately (internet reading so take it for what it's worth) says that a Traynor YBA-1 is almost a Marshall Plexi. You can pick those up on ebay for around $500. Other Traynors are much cheaper and are supposed to be really good amps. I have a YSR-1 on the bench now and the internals are layed out nicely and easy to work with. Plus the transformers are HUGE old Hammonds. I haven't gotten it up and running so I can't comment on the sound.

I also have an older (67'?) Ampeg SB-12 portaflex (7868 model) which is the best sounding, low wattage amp I've heard. It's breaks up nicely around 6 or 7, is tight and punchy, and won't make your eardrums bleed. The inside of this one is also layed out very nicely (for the most part) and is easily modded - which I see no need to do.

What type of tubes are you planning on using? I think EL84's have an earlier breakup than most power tubes but I'm not sure.

AL

[geertjacobs]

If you are considering reworking an existing amp, on AX84 the Laney AOR50 comes up sometimes as good starting point.
Having built 3 amps from scratch (AX84 P1, Orange OR80, Fender Preamp) and having converted one (mono HiFi into Vox AC15 Lite), i'd also go for conversion if possible.

If you start a 50 watter from scratch, visit http://www.hoffmanamps.com for checklists, board layouts and all kinds of useful info. I used their plexi layout to start building my OR80.

G.

[petemoore]

I always say what I read about building up systems.
 Figure out what your speaker needs are. Make sure your speaker[s are substantial enough to:
 A Handle the output of the amp
 B Sound Good at the high volume level you'll use.
 ...Start with 'better' speakers or learn a better way I doubt I'll have any use for.
 I agree with what's said about speakers by sound enthusiasts, ^ in the thread.
 I like my 4x12''ers [greenbacks] but I don't think the 'other' two are all that necessary till I get over say ... 30w.
 30w into two twelves [oversize cab suggested]...
 50w into 4x12''s...you'll 'actually' be 'using' the 'other' two speakers...by using I mean getting the amp to do it's distort trick without 'glanking' out the speakers. I think you may find you need the 4th speaker to get the 50 watter to do all it's can, without the speakers limiting or inhibiting frequency response etc.
 100w...you're playing bigger gigs than I am [we are?] if you need one of these...I had one...never really 'used' it...oh I played it plenty, but never used it for what it's supposed to do at higher settings...MUCH. A couple times I had the 8 speakers plugged in, and the warehouse to let loose in...WOW...WOWZERS...then it would do "THAT"...all the other times a smaller amp would have sounded much more 'Marshally' than my 100w SLP. Just too big for my britches...hardly ever really got it to do it's 'amp distort trick'...that is the reason I love tube amps...well it'd do the super clean, and it'd do distortion box tone, superbly...just won't do tube breakup without gettin' leaned on...and hardly ever got enough load to exhibit it's tube amp distortion/warmth characteristics...same ol story typed longer...
 For general, I say start with two great 12'' speakers, or figure out you'll certainly need 4 of them, and build another 2x12''...I use a 4x 12'' cab cause that's what I have...I like the added bass definition at gigs 'n jamms.