Jadis Defy 7


Hi,

I just got a Jadis Defy 7 (USED), I was wondering if anyone had instructions on how to bias the amp or can provide me a link where it explains the process.

Also right now there are 6550 Power tubes installed can I change them to KT-88, would this work or create problems for me.

Regards,
Satyam.
sbfx

Showing 1 response by jazz_nut

Satyam, you have to turn the amp on its side and remove the bottom plate. You will see 12 fuses (4 rows of 3). At the end of each row, there is a small round dial. This dial controls the bias for the 3 tubes that are in that row. You cannot bias each tube individually, this is why the tubes must be matched. With a volt meter, attach the ground to the metal chasis and the positive to the metal part of the fuse holder of the tube you are biasing, then slowly turn the bias dial until you are at the proper bias which I beleive is 4 volts. Just remember that the bias dial affects all 3 tubes in that row, so it is almost impossibe to get all 3 at exactly 4 volts. Repeat this proceedure for the other 3 rows of tubes. Caution, I am not a technican, just a former defy 7 owner. This proceedure worked for me. Good luck. Let me know if it worked