HK Citation 22 Bias Problem


Newbi Here,

Having a problem setting the right channel dc balance voltage. Supposed to be 60mv, but I get 12 volts with the trim pot turned down all the way. Anyone have an idea on this one.
motoservizio
Here is Paresh's address: [email protected] Just forward your last post. He said he would do his best to help.
Okay, I've sent a PM to Paresh at DIY. Hopefully he will respond to this thread:)
Csontos,

Let me be more clear. 60mv is called out in the HK service manual for dc balance in 8 ohm setting, 16mv is called out for idle current. The left channel adjusts to spec, no problem. The right channel idle current adjusts to spec. But the dc balance is 12v, with the dc balance trim pot turned clear down. If you turn the idle current down on the right channel, you can get the dc balance down to 7v. So apparently voltage is getting somewhere it doesn't belong. My tech is aware of the problem and has checked over the pc boards, has verified that it is as it should be. But has not been able to the bring the dc voltage down.
Mr. Paresh in other posts seemed to be aware of issues specific to this amp. So I was look for someone with direct knowledge.
Your tech needs to go back to school. I would definitely not confer with him any longer for anything! Did he at least confirm there is a problem at all? Dc offset should be as close to 0(zero) as possible. 60mv is quite high. However if you're talking about bias adjustment, it may not be. You haven't been all that clear. Which is it? Either way, 12v is so excessive as to be damaging. What reading are you getting on the left channel?
My tech has looked this over, and can't find the problem. There was a member here with some experience. Pmanaudio. Paresh please respond.
Swap the pot from l to r or replace pot.
if still have problem, check solder.