Biasing a Traynor YCS50

[fridgit]

Does anyone know where I can find the schematics/info/directions for biasing a YCS50 combo? I have a multimeter, I would just need to know where to place the multimeter probes and what setting I would need for the multimeter. I've already located the bias trim pot, I'm just not 100% on where the test points are.

Thanks!

 

[salvatruco]

Does anyone know where I can find the schematics/info/directions for biasing a YCS50 combo? I have a multimeter, I would just need to know where to place the multimeter probes and what setting I would need for the multimeter. I've already located the bias trim pot, I'm just not 100% on where the test points are.

Thanks!

this link would help you https://www.thegearpage.net/board/index.php?threads/423519&highlight=Traynor+YCS50H+bias the test points are the closest hole to the power tube on each power tube ( i used the extra hole as ground) the multimeter should be set to 200mv. also make sure that when taking readings the 50watts/15watts switch is set to 50 watts.... hope that helps

 

[fridgit]

Thanks! It looks like your link also gave me recommendations for EL34's as well. I appreciate the help!

 

[fridgit]

Okay, I tried out some JJ 6L6GCs & was able to bias these to 75mV. These actually sounded great with all Tungsol 12AX7s in the preamp.

I then stuck some GT EL34Ms in there and was only able to get one tube biased to 32-33mV, and the other tube to 26mV. I went ahead and played the amp this way and it actually sounds great! Even better than the JJs! I've never really used EL34s before, but I may never go back!

Back to the tubes & bias- I was very cautious to observe these tubes, since they were biased do funky, but the amp did not overheat, and the tubes did NOT red plate or give out, even after 15" of playing the amp with the MV @ 2:00.

Is this safe? Is the bias correct? I sent an email to Traynor Friday, so I'll see what they say, but I'd love some advice from you tube gurus on here.

Thanks!

And yes, I biased and then played amp in 50 watt mode.

 

[fridgit]

Anyone?

 

[fridgit]

Okay, I tried out some JJ 6L6GCs & was able to bias these to 75mV. These actually sounded great with all Tungsol 12AX7s in the preamp.

I then stuck some GT EL34Ms in there and was only able to get one tube biased to 32-33mV, and the other tube to 26mV. I went ahead and played the amp this way and it actually sounds great! Even better than the JJs! I've never really used EL34s before, but I may never go back!

Back to the tubes & bias- I was very cautious to observe these tubes, since they were biased do funky, but the amp did not overheat, and the tubes did NOT red plate or give out, even after 15" of playing the amp with the MV @ 2:00.

Is this safe? Is the bias correct? I sent an email to Traynor Friday, so I'll see what they say, but I'd love some advice from you tube gurus on here.

Thanks!

And yes, I biased and then played amp in 50 watt mode.

Bump

 

[donnyjaguar]

Isn't the schematic glued to the underside of the cover?