Class ab bias dumb question

[Maddart]

Looking at the amp board, it appears to me that the 5 W ceramic resistor would be the emit resistors that I need to measure across for my bias voltage. They read .5 ohn. K. I’m not sure if these are supposed to be .5 ohm or 500 ohm. I want to verify I need to measure across these specific resistors to take my bias reading. Approximately 15 mV is what I assume being there are no service manuals or schematics available for this equipment project one IVB.

 

[hamrules]

5 watt, 0.50 ohm, 10% tolerance (K = 10% tolerance).

 

[gslikker]

The 15 mV will be some 30 milliamps which indeed is a good guess

 

[Maddart]

Upon testing L channel was at 12mv / R channel was at 18 mv. Easily adjusted to 15 mv per channel.

 

[avionic]

Upon testing L channel was at 12mv / R channel was at 18 mv. Easily adjusted to 15 mv per channel.

Straight mains or on a dim bulb?

 

[Maddart]

Straight mains or on a dim bulb?

On the dim bulb tester. I thought that was volume all the way down all control set to center that it wouldn’t matter if it was on the DBT.

 

[gadget73]

if the bulb was very dim it probably won't matter all that much but I'd want to confirm when fed straight off the wall.

 

[Maddart]

if the bulb was very dim it probably won't matter all that much but I'd want to confirm when fed straight off the wall.

75 W per channel receiver, hundred watt bulb with no glow. I would think I would be safe to plug it into the wall now and just verify measurements.