DaveC113, Paul doesn't necessarily have a power amp with too much gain and a preamps' job does not have to be voltage gain. There is more than one way to get the job done and get enough voltage gain in a system.
You are better off if you can keep your signal path as simple as possible. If your speakers have enough sensitivity you can eliminate the preamps gain stage and the parts count in the signal path that goes with. With the de facto industry standard from most digital sources set at 2volts out, this leaves you with only the job of attenuating the signal from the source to avoid clipping from the amplifier. This assumes that the amp has an input sensitivity of less than 2volts to produce full power output.
In my particular case, I have 95dB sensitive speakers and an amp with an input sensitivity of 1 volt for full power out. This lets me use a zero gain, zero feedback buffer to control volume, instead of a preamplifier with gain. It also allows me to reduce the parts count in the signal path. My buffer has only one active device in the signal path and the power amplifier has five active devices, for a grand total of six. The KISS rule of engineering actually does yield benefits if you stick to it.
Scotty
Well, my perspective is from building tube equipment. In my 2 stage SET amp, there are compromises that will need to be made if you want enough gain without an active pre, such as a higher gain driver tube that is less linear. I use a lower gain driver that is more linear and capable of handling a lot more current than higher gain alternatives, therefore I need a preamp with gain... or a 3 stage amplifier... or a 2 stage that makes some sonic compromises to have enough gain.
IMO, it is better to have a quality 3 stage amplification system rather than the compromised 2 stage. A high quality preamp with it's own separate power supply can perform voltage gain more cleanly than an integrated amp with a 3 stage design and one power supply for all 3 stages.
And I believe this sticks with the KISS principle, which I agree with. I have half the active devices in the signal path as you, and I hear tubes can be pretty linear.
But since this thread is about digital amps, the design considerations are going to be very different vs tubes.... I will stick with my tubes for now. I know very little about class D vs class A amplification.
Oh, also I still think Paul has an amp with too much gain if it can't switch sources and volume and he wants to use it with an active preamp. Seems like the issue is gain structure, not how many chassis the amplification is in. I mean, if you wanted to you could have a bunch of separate chassis for each amplification device and each power supply. If they are monoblocks you could easily have your amplification in many different chassis. I think the proof is in the result, whether or not the designer thinks there is a benefit to multiple chassis depends on his design choices and one alternative (a single chassis for everything) may or may not be best.
