Bogner TJ Bias Resistor Question "HELP"

[bwgintegra]

Just bought a used TJ with kt88. I have a new set of SED el34 to put in. I pulled the chassis and on R402 I have one 22k resistor and on R401 I have two 33k resistors in parallel to equal 16.5k. From what I have read in the other threads this is different.

Also what type of preamp and poweramp tubes does bogner ship with these new and whats up with the two orings around one of the preamp tubes.

Wondering if the previous owner messed with the amp.

Thanks for any help

Also when I got the amp the Kt88's bias was 40mA

 

[glip22]

The rings are just tube dampers that come stock in the amp. Right next to your fuse holder, you should see two resistors, one on top of the other. Desolder or snip the one that is piggybacked on top of the other. Might I suggest Gold Lion KT77's instead of the 34's. I had Winged C EL34 in mine and the GL KT77's are quite a bit better in this amp. You need a hot quad after you remove the resistor. TC tubes can help you. He's burning in a bunch of them now. His testing and service is top notch. Pic was supplied by a forum member here.

 

[bwgintegra]

What was the color code on the resister that was removed.

Steve k said in another thread that the paralleled resistors are 33k and 22k, mine are both 33k

22k red,red,black,red,brown
33k orange,orange,black,red,brown

 

[glip22]

Doesn't matter. Just remove it and you'll be fine. 10k is not going to make a difference.

 

[bwgintegra]

de-soldered the top resistor and biased up the el34, worked great and sounds even better!

Thanks

 

[glip22]

de-soldered the top resistor and biased up the el34, worked great and sounds even better!

Thanks

Awesome!!! Much better than the 88's. Now order yourself a quad of Gold Lion KT77's from TC tubes and you will be very happy. You just need a hotter quad and they will bias up perfect. Tell Tyler you need the same as Gary. He knows me well enough. He's a great tube seller. I can't recommend him enough.