Newbee is correct. I would also check the actual bias supply voltage. It's possible that it's low to begin with in which case either resistors or a resistor have changed value. It's possible you have a bad filter capacitor causing the lower than spec. bias supply voltage, or you have a rectifier diode or diodes that are leaky and need to be replaced. Happy hunting. G
Can't get proper tube bias per manual
Hi All,
Regarding a MCIntosh MA-230,
How important is it to set the bias according to the manual?
Mac states set idle voltage to .7 v. Best I can get is .3 to .4
Considering it's age the amp sounds very exceptional, Does the amp have a problem that needs to be urgently addressed or am I just being overly cautious?
Looking at the schematics, I could drop the values on a set of 4 resistors to change the levels, but need to check with the experienced on this.
thanks..
Regarding a MCIntosh MA-230,
How important is it to set the bias according to the manual?
Mac states set idle voltage to .7 v. Best I can get is .3 to .4
Considering it's age the amp sounds very exceptional, Does the amp have a problem that needs to be urgently addressed or am I just being overly cautious?
Looking at the schematics, I could drop the values on a set of 4 resistors to change the levels, but need to check with the experienced on this.
thanks..