How to match preamp gain to amp sensitivity?

This is a tough problem. Several possibilities:
1. Attenuators at the amp inputs.
2. Sources (e.g., some DACs like the Benchmark) with variable output level
3. A preamp with electronic or other finely-stepped volume control (like the PS Audio PCA-2 and a bunch of others) - the big issue is usually that rotary volume controls give little room for adjustment if there is too much gain - actual input overload is rare these days.

Best bet - try the preamp with a system that has similar amp gain and speaker sensitivity to yours, and see if you're happy with the ability to adjust the volume easily, especially at low levels. When doing so, beware of the tendency to listen much louder in the showroom that you typically do at home. We've had dealers comment on how quiet we like to listen, when we thought we were playing music loudly in their showrooms!

Hi, Alun -- I've used a couple of passives, McCormack TLC-1 (still in my office system) and EVS Ultimate Attenuators. Like many folks, I thought there was a tradeoff - excellent transparency and smoothness, some loss of perceived dynamics, especially in the bass. I also prefer to run long interconnects to my amp, which does not work very well with passives (I'd say not more than a meter or at most two). Audio Research amps generally have very high input impedance, which will help with some of the issues. I see the Placette passives on Audiogon for attractive prices, so you might give one of them a try.
Rich

Alun - One easy (and not too expensive) thing you might try with your current preamp, to get a sense of what you want to look for in terms of gain, is (assuming you're using unbalanced connections) the Harrison Labs in-line attenuators. Parts Express (www.partsexpress.com) sells them in 3, 6, and 12 dB versions. In my experience, they're pretty transparent -actually better than the more expensive Rothwell attenuators. And once you have them, they come in handy for non-critical sources or secondary systems.

And in terms of overall system gain - it really doesn't matter whether it comes from preamp gain, power amp gain, or speaker sensitivity - the bottom line is, do you have good range of control on the volume adjustment, without problems of noise, etc.
Rich