Low Power DR ?

[thunderfoot]

Hi - I'm looking for some feedback and "how-to's" regarding making or modifying my amp into a low power amp - like a PR (10-12 watts maybe even less !!!).

I have both a PR and a DR. For some of the blues gigs I do, a DR is too loud by the time it hits it's sweet spot. In fact, sometimes even the PR is too much. I am doing a 3 pc blues gig in some smaller rooms that only hold 40-80 people.

I would love to belive it's as simple as changing the transformer, but I'm sure it's not, right?

Any ideas?

www.torresengineering.com,half power switch,12ay7, 12au7,5751 for V2 or PI will suck the loudness right outta that D.Half power-or pentode/triode-plus 5751 for V2,12ay7 for PI worked great on my '73 pro.I have an '80's Princeton Reverb II that is hard to play with because there's no bottom end at low volume,but the pro's trannies keep the sound nice and fat with a nasty,greeezy break-up around 3-4 with treble on 1,bass on 3,bright switch on.With the tube swap,ya never hafta open the chassis which has worked fine on what I've seen on stage.The substi-tube or even yellow jackets adapter for EL84's may even be a big help(preamp tube swap is still way cheaper)

[Chris / CMW amps]

Post PI MVs will help for sure, I do prefer them above (most) soaks.

(or changing the 1M resistor in front of the splitter to a 1M volume-pot-type-circuit in the PrincetonReverb, DR: just a dual 250k A pot io. the two biassplitters).

[Fretts]

Enzo knows a lot about this sort of thing, maybe he will chime in here...
O'Connor has a practice of increasing the screen resistance to influence the behavior of the power tubes...
I haven't tried these things myself so I can't attest to what they do to the character of the amp's final sound, but it looks easy enough.

[Aphid]

I'll just chip in and mention that I have THD hotplates on a Vox AC30, a Fender Twin and a Marshall JTM45.

Ultimately the attenuated never sounds as good as the raw, but then thats not really surprising when you think about it... when those amps are cranked flat out you don't just hear them, you FEEL them!!!

I've tried a number of amps with master volume and I've always been dissapointed on account that they don't even come close to what they should sound like. Having said that, it's less of an issue on the Fender or Vox where I'm looking for clean tones and not pushing the output tubes. Looking for crunch on any Marshall amp with a master volume though is an excercise in futility (unless the MV is at 10 of course).

In my humble opinion the hotplate attenuated sound is the best way to get pretty damn close to the cranked sound at a sensible volume. Versatility is also a big factor, you can safely play at 4am and even the dog will sleep through it... gig in a small venue - no problem, just knock 8db off... gig in a hall? Just unplug the attenuator altogether!

Ultimately if you absoultely must have that flat out sound then you are going to have to live with the volume. Probebly worth noting that when I crank the marshall I can clearly hear the speakers breaking up - you are only EVER going to get that sound when the speakers are flat out.

Anyway, thats my peace. At the end of the day I think we should all be aspiring to make that $20 battery powered transistor micro-amp sing like a bird!