Parasound HCA 2200II - idle current question

[cortico]

Just checked the bias setting on this power amp. Both channels were set at 10mv across emitter resistors, the service manual calls out to set it at 20mv (+-2mv), no load, after the amp is running for 1/2 hour and then readjust after it's stabilized.

I proceeded as per manual, noticed the following when powering the unit on with the voltmeter leads attached across emitter resistors:

Right channel idle current climbs up from 0mv to set value +-17.5mv
Left channel idle current climbs up to about 22mv and than comes back to +- 17.5mv, looks like it's drawing more current at startup.​

Is this a reason to be concerned?

Thanks

 

[BinaryMike]

That looks like pretty much normal variation in behavior to me.

 

[BobHol]

Yeah, the differences between left and right are not significant in my humble opinion.

 

[avionic]

Is this a reason to be concerned?

No..

 

[cortico]

Thanks!

On another note, The power on and standby LEDs on my HCA2200II amp don’t turn on, not sure if warning leds are working either, never saw them on.

Regardless the annoyance the relays click in after a few seconds the power bottom is flipped into “on” position and the amp runs stable and sounds beautiful .

All visible interior wiring is apparently connected. Resistor R145 leads measure 76v and 6v in reference to ground, I though it was bad but apparently is doing its job... any idea where to look?

 

[BinaryMike]

That's what I call Mickey Mouse logic. You'll just have to dope it out, step by step. Is there enough voltage across either of the LEDs to make them light?