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

Showing 2 responses by batch68

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).
Jed,
You want to get matched gain. I'd recommend balanced triodes as well, but that one is not as essential. I wouldn't worry too much about the other options. And Tom is correct that the pre-amp tubes on that Jolida are the 12AX7s and they will make the biggest difference in terms of shaping the sound. The 12AT7s are driver tubes and you shouldn't spend as much on them. Get something quiet and reliable and don't worry about their supposed sound characteristics. Spend plenty of time listening to the amp with what's in there now & decide what you want to change regarding the sound -- post that here & you'll get loads of recommendations. I have some Jolida gear as well, they're great bang for your buck amps.
Batch