Krell KSA100 MKI power consumption

Jsd52756, 7 amps at idle for the KSA 100 seems about right. Dont't forget that the KSA 100 is class A all the way to 100 watts. The KSA series of amps did not have a sliding or sustained bias outputs as the newer models.

Jsd52756, the FPB300cx uses 60w on standby, 175 at idle and 1700w at full output.

guys, 7 amps at 220 volts converts to ~2000 watts. I don't think that makes sense.

The read on my meter is ~350 watts.

Mr. D'agostino (this amazing guy responded to my request immediatly!) says:
"The Ksa !00 did operate in pure class a. The top of the amplifier does not reflect the heat. After about 1 Hr of operation the bottom of the heat sink should be about 65 degrees c . I allways set the bias with a current prob. I could not tell you what voltage you should
measure across the emitter resisters. I no longer remember."

We assumed a North American Standard of 7amps x 110v = 770 watts. Take a look at another 100w amp and see what the current draw is at full output, because in Class A, your amp is at full output at idle...that is why it gets so hot because it need to dissipate all that power when not driving a load.

My old (100w Class A) ML 20.6 amps drew 500w each at idle for a total of almost 10 amp (1000w). Since the Krell KSA 100 is also 100w Class A, 700-800watts at idle does not seem that far off.

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.