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Re: Charles, regarding a) above, what is your thought that...

I wish I had a great answer for you, but I don't.

When we first started Ayre, we used a passive preamp between our reference CD player and our power amplifier (our first product). We quickly found that different passive preamps yielded different levels of performance, and went through a few of these. By far the best sounding was a custom-made fixed attenuator comprising a pair of rhodium-plated connectors soldered back-to-back with two resistors permanently soldered in place to give a single fixed volume level. No switches, no wires, just two connectors and two resistors. (All of the passive preamps and attenuators were plugged directly into the inputs of the power amp, so there was no issue concerning driving an interconnect cable.)

So when we made our first preamp, I was wondering just how much *worse* it was going to sound compared to our reference fixed attenuators. I was stunned to find that it sounded *better*.

There was a very slight loss of resolution, but that was more than made up for by increased focus of each instrument, improved weight and impact in the bass, a larger soundstage, and a greater sense of musical ease and flow.

I'm really not sure why this was so, but it certainly was. Here are a couple of possibilities:

a) The power amp was more sensitive to RFI than was the preamp. Somehow the preamp was filtering out RFI that was getting through the passive preamp.

b) The output impedance of our reference fixed attenuator was around 900 ohms, while the output impedance of the active preamp was 300 ohms. It may have been that the input stage of the power amp "preferred" seeing the slightly lower source impedance.

I find neither of these explanations to be very satisfying, in that I don't think they are telling the full story. But here it is ten years later, and I still don't have any better idea what is really going on here. However, I am quite confident that (at least in this case) it is *not* a case of "adding favorable colorations to create a more musical sound".


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