does amp draw alot of power when volume is zero

If it is an AB amp, probably not much; if it is a Class A amp or biased well into Class A it will draw the full amount of current or a substantial portion of it. This is easy to tell, just feel the heat sinks when it has been on but not playing music, if they are cool or lukewarm leave it on all the time. If you burn your finger don't leave it on. Most amps draw a minimal amount of current and sound better left on.

Stanwal is right. My Krells act like frying pans even in standby.

If you are worried about wasting energy, and money, on idle music systems you should consider Class D amplifiers. These amplifiers are very efficient in use and at idle. My desktop integrated amplifier draws 15 watts at idle and sounds great.

For those who are actually curious, spend the 25$ on a 'kill a watt' power meter.

This meter will not only give you line voltage, but current, watts, VA AND therefore powerfactor.

A cheap test and part of my standard kit, though never left in system for long.

http://www.p3international.com/products/special/P4400/P4400-CE.html

Thanks for all the suggestions. Mine is a class D bel canto, fairly cool at idle, just a couple of warm spots but certainly not hot.

With a Class D amp; the output devices are turned off(no bias), until a signal is detected= high efficiency/low temps/low current draw at idle. Class A has full bias applied to outputs, ALL the time= low efficiency/lots of heat/high current draw at idle.

Agree with Magfan on the Kill A Watt; it has many other uses apart from audio.

Purchased mine at Radio Shack.

Tswei,
Bel Canto uses B&O ICE modules. I don't know how many changes / upgrades are made.
However, the B&O data sheet says efficiency is in the 80%s at full power. Lower efficiency at lower powers. This is 'plug to speaker'
My ASP moduled PSAudio is cool even at high powers....but if I close the cabinet, it CAN get warm, even at the few paltry watts I draw under normal conditions.

Bel Canto publishes the idle power draw in the owners manual, as do many other manufacturers. Their current integrated (s300i) idles at 15 watts. I would leave it on 24/7.

Y'know, if you are concerned about power usage, its really a good idea to turn the stuff off when you are not using it.

I've been interested in solar power for a long time. I was shocked (hah! pun intended) to find out that the length of time it is on often plays a bigger role than how much power it draws.

It is a fact with audio that the hotter stuff often sounds better, as heat is being traded for lower distortion. So if you base a system entirely on heat generation, be prepared that the results may not be aligned with 'best sound for the money'.

Atmasphere,
For many years my ears have confirmed your insightful statement with very few exceptions.