Krell KSA100 MKI power consumption

Real class A is about 25% efficient so 100 + 100 watts should require that amount x4 or 800 watts. Remember that true class A amps draw FULL current at idle. I use to sell the KSA 100s and they did draw a lot of current. Later Krell designs use a more efficient bias method in many cases.

it is 7 amps on a 120v circut on idle. But that is halved to about 3.5 amps on a uk 240v circuit. Amps are relative to voltage. 

Used to have (and loved) a pair of the KMA100s and they could certainly heat up a room-especially at idle or low volume. Would not be at all surprised if your KSA100 drew 7-8 amps at idle.

Fantastic amplifier the KSA100. 
I have mine hooked up to a dedicated 20amp line, and yes it draws 7-8amp at full power. 

I currently have a Krell KSA 50S with the sliding bias. The 50S was the baby of the line, 50 watts at 8 ohms. Class A and a wonderful amp. 

Mine runs as cool as a cucumber also.