Non-distorting clean boost

[gotdabluz]

sorry if I am trying anyone's patience with this post.  I know that boosters are covered under numerous previous posts, but can't really find one that applies to my need here.

I got this nifty Trademark 10 amplifier made by Tech21 . . . I love it . . . all the tone shaping abilities I could possibly ever want.  Still I long for a couple extra little features.

All the distortion effect on this amp is generated in the pre-amp . . . it's essentially an enhanced SansAmp coupled to a clean amplifier

One of the things I would like would be a non-distorting clean boost stompbox that I could possibly insert into the fx loop (which comes after the SansAmp stuff) . . . I want to be able to raise the volume a few db without causing additional distortion  and preserving the full tone of the signal as much as possible

Could someone guide me to the best applicable cicruit for this endeavor?

Thanks!

[vanhansen]

Two right off the top of my head that get raves here are the AMZ Mosfet Boost and Dragonfly's "Sparkle Boost".

A couple of others that I like are the Fetzer Valve from Runoffgroove and one I designed, the Marsha Valve.  Although the two may be similar, each sounds quite different.  I wouldn't say these are 100% clean but they do the job.

[R.G.]

Sigh.

The best clean booster is also the simplest - use an opamp with a large power supply, say +/-18V. Substantially everything else colors or distorts the signal. It may color or distort it in a way you like, but it's coloration or distortion nevertheless.

Beyond that:

I want to be able to raise the volume a few db without causing additional distortion and preserving the full tone of the signal as much as possible

That may not be possible. Due to the human ear's logarithmic volume sensing, a 3db increase of signal level is a just perceptible increase in volume. To get a perceived doubling of loudness, you need ten times the power, or over three times the voltage.

I don't know that amp intimately, but I'd be willing to place a modest bet that you can't pump three times the preamp's output into the power amp without pushing the power amp into distortion of its own. In fact, the most likely scenario is that the power amp distorts just a hair above where the preamp limits.

As I said, I don't know the insides of the amp, but don't get your hopes too high.

[bwanasonic]

Don't rule out the simple solution of a passive volume control in the loop that you can bypass for a *boost*.

Kerry M