Traynor YBA-1 Mark II bias question.

[BlacknWhite]

Hey guys just a quick question. I own a couple tube amps which I bias and Change tubes on my own but they are newer amps and have test points and bias pots. I'm picking up an old YBA-1 Mark II tomorrow and I was just wondering the best way to check the Bias on it. It has been re cap'd and re tubed by a local tech already but It would be nice to know down the road. Thanks in advance.

 

[BassmanPaul]

The best way to deal with a tube amp with non adjustable bias is just to leave the darn thing alone. Many, many amps have been damaged by owner attempts to adjust the bias. The knowledgable folk who designed these amp knew what they were doing. Please don’t try to second guess these folk. The difference messing with the bias will make will be negligible!

 

[BlacknWhite]

The best way to deal with a tube amp with non adjustable bias is just to leave the darn thing alone. Many, many amps have been damaged by owner attempts to adjust the bias. The knowledgable folk who designed these amp knew what they were doing. Please don’t try to second guess these folk. The difference messing with the bias will make will be negligible!

Oh I had no intention of messing with the bias on an old amp with a fixed bias. My knowledge is far from that hahah. With my newer amps I check the bias if I change tubes and re bias as needed because its so easy. I just like to be able to check once a year to see what its sitting at. If I ever needed actual work done it goes to my tech.

 

[jbybj]

The best way to deal with a tube amp with non adjustable bias is just to leave the darn thing alone. Many, many amps have been damaged by owner attempts to adjust the bias. The knowledgable folk who designed these amp knew what they were doing. Please don’t try to second guess these folk. The difference messing with the bias will make will be negligible!

Unless of course, the fixed components that regulate the bias, have drifted out of spec, or failed. Then I imagine the knowledgeable folks who designed the amp would recommend replacing those components with ones of correct values.

In proper working order, Traynor YBA’s are amazing amps. There is a cornacopia Of info out there to be Googled.

 

[BassmanPaul]

Obviously if the amp has failed in ANY way it will need to be repaired. I would have though that obvious!

 

[BassmanPaul]

Oh I had no intention of messing with the bias on an old amp with a fixed bias. My knowledge is far from that hahah. With my newer amps I check the bias if I change tubes and re bias as needed because its so easy. I just like to be able to check once a year to see what its sitting at. If I ever needed actual work done it goes to my tech.

Even those amps with a pot are still referred to as “Fixed bias.”

 

[okcrum]

In this case it's pretty simple. Check for -46V on the bias supply with a multimeter. Done.