Hey guys,
I just bought my 2014 Diezel VH4 from Reverb (looks like it's in great condition, seller claims it was barely played) and it's my first tube amp. I bought an apex match quad JJ KT77 from antique electronic supply. I am using the tube amp doctor biasmaster. I also have tube amp doctor 12AX7 PreAmp tubes.
I hooked up my bias master and tubes and such. First off, I'm running the switch on EL34. When I checked the current, Tubes 1 and 4 were running at a good current- 32 mA which I wanted to crank up to 35 mA for a good bias for my JJ KT77's. However, tubes 2 and 3 were running near 45 mA. I tried playing around with the knob that changes the bias (I forgot the exact term), and I was able to get tubes 1 and 4 to 35 mA, but means that 2 and 3 went up to 47 mA.
I did some trouble shooting- changing tubes, probes, etc, and it turned out that it was the tubes themselves that were running too hot. I was wondering what I should do at this point? Buy new tubes? If I were to buy new tubes, should I just get an apex matched pair to replace tubes 2 and 3, or should I get an entire new quad?
I just bought my 2014 Diezel VH4 from Reverb (looks like it's in great condition, seller claims it was barely played) and it's my first tube amp. I bought an apex match quad JJ KT77 from antique electronic supply. I am using the tube amp doctor biasmaster. I also have tube amp doctor 12AX7 PreAmp tubes.
I hooked up my bias master and tubes and such. First off, I'm running the switch on EL34. When I checked the current, Tubes 1 and 4 were running at a good current- 32 mA which I wanted to crank up to 35 mA for a good bias for my JJ KT77's. However, tubes 2 and 3 were running near 45 mA. I tried playing around with the knob that changes the bias (I forgot the exact term), and I was able to get tubes 1 and 4 to 35 mA, but means that 2 and 3 went up to 47 mA.
I did some trouble shooting- changing tubes, probes, etc, and it turned out that it was the tubes themselves that were running too hot. I was wondering what I should do at this point? Buy new tubes? If I were to buy new tubes, should I just get an apex matched pair to replace tubes 2 and 3, or should I get an entire new quad?