Amplifier input tech question

Ska_man, your problem is not uncommon, and is easily fixed without changing any of your major components (although I recognize from your posts that you appear to want to do that anyway). Just get a pair of Rothwell attenuators (made by the company whose website Dave linked to). An Audiogon seller (with whom I have no connection) is offering them here: http://www.audiogon.com/cgi-bin/cls.pl?accstwek&1260621019&/Rothwell-10-dB-attenuators--rc.

Contrary to what has been said, DO NOT address the problem by selecting a component with a substantially lower input impedance. That will most likely introduce frequency response irregularities into the system, because the output impedance of the component driving that input will most likely not be constant with frequency.

Given that the problem is simply that your volume control needs to be set at a non-optimal point, and that there is no indication of clipping or other severe distortion, I would add that the root cause of the problem is that the overall combination of preamp voltage gain, power amp voltage gain, output voltage from the source component, AND speaker efficiency/sensitivity, is too high. In other words, it is not generally possible to assure that this kind of problem will be avoided simply by constraining the relationship of preamp output voltage to power amp input voltage, or by focusing just on any other specific interface between components. It is a system-level issue.

Good luck!
-- Al

As Bob very correctly indicated, the 8 volt maximum output of the preamp is irrelevant. A preamp with a significantly smaller maximum output specification would not help the problem you are trying to address (everything else being equal), and if that number were much lower than 8 volts a new problem might even result, clipping of its output stage on high volume peaks.

What is relevant is the preamp's gain, which as Dave indicated is a factor of 5 (200mv in producing 1v out), which is a gain of 14db. That is certainly NOT particularly high.

Also as Bob correctly indicated, the power amp input sensitivity of 1.68 volts is a fairly typical number, and most power amps with similar output power ratings (200W in this case) will therefore have similar voltage gains.

Your speakers appear to have a sensitivity rating of 91db, which is higher than average but just slightly.

Therefore to the extent that it is meaningful to identify a "culprit," Bob's suspicion is probably correct. The DAC is probably putting out an excessively high voltage.

But whether it is or not, as I indicated in my previous post a simple solution is to insert in-line attenuators.

Regards,
-- Al

Ska_man, my previous post was written before I saw your last post, addressed to me. You're very welcome, and thanks for the compliment!

Best,
-- Al