Jolida jd-502p

Gentlemen,
I strongly urge you to do some reading on 12AX7 tube spec regarding Max heater to Cathode Voltage.
The spec says 100V.
SRPP based configuration calls for a raised filment to avoid this stress.
Jolida does not have raised filament, just an AC supply with a grounded (vs raised) center tap.
Your prized vintage tubes will have one triode in each tube aging real rapidly.
The $$$ wasted on premium vintage tubes can buy you properly designed amps.

First, I'm no gentleman. Second, instead of wasting my $$$ on vintage tubes I'm merely enjoying my inexpensive, although perhaps not properly designed, Jolida. Apparently the rapidly aging triodes sound great. Who knew? WU KNEW!

Hi Johnsonwu

Again my posts are never as funny as Wolf's but here goes. Thanks for posting the information you did. You saved me at least $100 on vintage 12AX7 and 12AT7 tubes. (More money for records now!) Even if I read the 12AX7 specs I never would fully understand it and I definitely would not have known about what you said about the Jolida. I had to google what SRPP meant. I'm sticking with the 502P as a CJ Classic Sixty SE is still way out of reach for me.

I can tell you from personal experience how much better a Jolida piece I once owned sounded after I rolled the tubes. At that time it was expensive but clearly not as bad as it is now for the better truly strong old stuff. I used Upscale Mil Spec Mullard CV 4004s. The impact on the sound was so great that I found it unlistenable without those tubes in place. That was before the advent of all of the reissue 12AX7s. I like them as well but still imagine that the improvement made by true Mullards is worth the investment. If you can somehow borrow a friends NOS tubes I think you will understand what I am saying. Ordinarily I would tell you to use 5751s but unfortunately the one and only circuit where they simply did not function was the Jolida.

I used 5751s in my system to great satisfaction when I was using monitor speakers. I later moved to full size speakers and the system sounded flat. For the larger speakers I went back to the 12AX7 tube and it provided significantly more dynamic performance.