If there is anyone besides me on this forum that is using a Jadis Defy 7 amp and needs to know how to bias this amp, let me know. Good information on how to peform the bias procedure for this amp is hard to find.
I was able to fix my Defy 7. I had 8 blown cathode fuses and 1 open cathode resistor. I replaced the cathode fuses and the cathode resistor and installed a new set of GL KT-88 tubes. The bias is set as perfect as you can get with a Defy 7 which only has one bias pot for each bank of 4 tubes and you are shooting for an average of 4v across the 3 tubes in each bank. You can bet that I will be keeping a close eye on the bias by checking it regularly even though it is somewhat of a pain in the ass even if you know what you are doing. You also need a good DVM and a pair of 4 ohm 100 watt dummy load resistors.
The good news is that my Jadis is singing again and the GL KT-88 tubes sound great. I bought the tubes from Kevin Deal at Upscale Audio. They did a really good job of matching 11 out of 12 tubes but I had one tube that was "wacky" in comparison to the other 2 tubes in the bank of 3. I contacted Upscale Audio and they apologized and sent me a replacement tube that better matched to the other 2 tubes in that bank. The new tube arrived Friday and it is installed and all is well. I know some people complain about Kevin Deal, but I personally have had zero problems with him. Maybe because I always start my conversation by saying "I need to place an order for some tubes."
I was able to fix my Defy 7. I had 8 blown cathode fuses and 1 open cathode resistor. I replaced the cathode fuses and the cathode resistor and installed a new set of GL KT-88 tubes. The bias is set as perfect as you can get with a Defy 7 which only has one bias pot for each bank of 4 tubes and you are shooting for an average of 4v across the 3 tubes in each bank. You can bet that I will be keeping a close eye on the bias by checking it regularly even though it is somewhat of a pain in the ass even if you know what you are doing. You also need a good DVM and a pair of 4 ohm 100 watt dummy load resistors.
The good news is that my Jadis is singing again and the GL KT-88 tubes sound great. I bought the tubes from Kevin Deal at Upscale Audio. They did a really good job of matching 11 out of 12 tubes but I had one tube that was "wacky" in comparison to the other 2 tubes in the bank of 3. I contacted Upscale Audio and they apologized and sent me a replacement tube that better matched to the other 2 tubes in that bank. The new tube arrived Friday and it is installed and all is well. I know some people complain about Kevin Deal, but I personally have had zero problems with him. Maybe because I always start my conversation by saying "I need to place an order for some tubes."