2. amps-preamps
  3. 1337876441

Driver/Input tubes

I need somebody to either explain or steer me to an explanation of the 12AX7/12AT7 tube's purpose in my Jolida JD502P power amp. I get preamp tubes in a preamp, but I've found it difficult to find a clear explanation of what the "driver" and "input" tubes are actually doing, and their relative importance to the sound of the amp. The 502P seems to have a typical compliment of these tubes, sharing its basic design with a lot of apparently similar power amps. Brain trust...hep me...hep me...
wolf_garcia
wolf_garcia OP
6,708 posts
 
I appreciate all of this...although I think my comprehension capabilities are being woefully overestimated. I'll look for the schematic...but bear in mind my amp is a 502P basic power amp, NOT an integrated, hence the query.
hifigeek1
770 posts
 
Wolf, who knew your amp was such a 'swinger'.....
jedinite24's avatar
jedinite24
1,503 posts
 
Stupid questions coming up. Does this mean that it is a must for the 12AT7 and 12AX7 tubes to be matched (each triode of the preamp tube has matching gain) and balanced (when the plate current draw of each triode is the same)for the Jolida 502P? I found that some tube sellers add a surcharge for this service.
marakanetz's avatar
marakanetz
5,473 posts
 
Jedinite, you don't have to match 12AT7 or 12AX7 at all.
batch68
27 posts
 
Jed,
If you are asking about matching the AT7s to the AX7s, then no. If you are asking if you should have matching AT7s (or AX7s), then I'd strongly recommend it (not absolutely required, though).
More to discover