Will this isolation transformer limit power draw?

The transformer is probably OK for any reasonable home use of the amp, but why the heck are you using the transformer?

Lak...Some questions...

1. If a transformer removes "grunge" (that must be some technical term that I am unfamiliar with) why doesn't the transformer that is already in the audio equipment do the job?

2. Why doesn't power supply capacitance do the job? If this is a real problem, a PS filter using a series inductor between capacitors would be a lot cheaper than a transformer.

3. Why does the AC power need to be "grunge" - free? Low powered amps can use the applied audio signal as their source of power.

4. Of the many people who have bought power conditoning equipment, how many had measurements of their AC power to determine if they had any "grunge" to worry about?

sean...Thanks for the straightforward answers. I could respond with follow up questions, but I doubt that we would ever agree completely.

My concern (probably too strong a word) is that many audiophiles spend a lot of money on things that have no (or very little) benefit because they have no engineering knowledge and are easily misled by half-baked pseudo-scientific smoke and mirrors.

About the audio amp that is powered by the audio signal, I can't remember exactly where I came across this: it would obviously be some unique situation, perhaps an impedance matching matter. Of course, electrostatic headphones use the audio signal to generate their high voltage bias. In my previous incarnation as an aerospace engineer we used a square wave instead of a sine wave for ac input power. It's more efficient, and the dc comes out the same.

Sean...Using an audio program instead of 60 Hz for power is obviously an extreme case.

Isn't it true that the diodes of the power supply only conduct during time intervals when the input 60 Hz voltage is greater than the rail voltage. Most of the time the diodes are not conducting, and the amp "coasts" on what is stored in the PS capacitors. When the amp is under no load, the PS capacitors will charge up to the 60 Hz peak voltage, and the diodes will just be delivering very brief pulses to keep them charged. So, if the power supply has pulses for input, why does the exact shape of the original waveform matter?

In the good old days, an outboard "bank" of capacitors was a popular mod...simple and effective. I believe it would do more good than a transformer.

sean...60 Hz ac sinewave input power is at zero volts 120 times per second, and below rail voltage most of the time. (That's why we found a square wave power input was better).

Outboard location of some PS capacitance is OK. After all, some designs (usually "High End") put the entire PS on a separate chassis. Also, it is usual to have some small amount of PS capacitance distributed right on the active circuit boards to minimize the effect of inductance between the PS and the circuits.

Shall we now start a bragging contest to see who has the biggest capacitor :-)

Sounds like the Bryston has a problem.

Does it hum or buzz when input interconnects are disconnected (ie: only the power amp is connected to the speakers)?

Other ideas...Are the source components and the power amp pluged into different outlets, which may be on oposite phases of the 115 V power? Try putting everything on one plug.

Try the interconnects the other ("wrong") way around. Sometimes this is better.

If this is why you are thinking of an isolation transfromer make sure you can take it back for refund when it doesn't work.