does amp draw alot of power when volume is zero

I seem to forget to turn off my integrated alot. IF no music is playing, does it still draw power??
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.
Agree the best simple way to know if your stuff wastes power at idle is the see how much heat it puts out when idling. Nearly all the electricity used at idle is going into heat. The warmer the stuff is at idle, the more electricity you are using at idle.
My prior amp (forte 4a) was a small furnace at idle, and was just as hot idling all day as it was playing hard all day, Class "A".
My current amp, a Bryston 4B-SST2 has more surface and less apparent heat output per square inch, but it is much bigger and twice as heavy as the Forte.. so it is hard to say if it is more efficient?
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.
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.
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'.
For many years my ears have confirmed your insightful statement with very few exceptions.