Tim64
Super Member
Went with the standard version.Nice! Did you go with the gold pin version, or the standard? I may go that route myself to wake up the highs on this.
Went with the standard version.Nice! Did you go with the gold pin version, or the standard? I may go that route myself to wake up the highs on this.
Too bad my amp doesn't use a 6DJ8 or equivalent--I used to use one of those Musical Fidelity tube buffers, and I have three spare pairs of tubes from it, plus a single Amperex 7308 gold pin (which sells for north of $75). I likely will sell these off, along with the buffer, since my preamp uses M8080s and I wasn't all that excited about the buffer anyway.
Interesting. I can't say I really like this amp (I have the TubeCube|7 branded version of one of these APPJs), but if this opens up the top end and flattens out response to where it should be, I may be willing to dig in and try it. It is OK in my desktop system (due to nearfield listening), but it sounds dull in any other system. They are known to have a high-frequency rolloff. (I didn't find this review until I had purchased mine...and it explains the dull sound.) The tube upgrade did help--I'm running all new-production Mullards in it. Still, not ideal.So I've replaced the stock 0.1uf coupling caps in the PA1502A with WIMA 0.47uf MKP4 caps, and I'm kicking myself for not doing it sooner! This was already a pretty good amp (esp. with NOS tubes) but WOW, it's superb now! Some folks on the Head-Fi thread have gone further with 1000uf cathode caps in place of the 220uf caps and audiophile coupling caps instead of WIMA. The PA0901A uses almost the same circuit, but with allowances for EL84s instead of 6V6s, so replacing the coupling caps will yield the same results.
Interesting. I can't say I really like this amp (I have the TubeCube|7 branded version of one of these APPJs), but if this opens up the top end and flattens out response to where it should be, I may be willing to dig in and try it. It is OK in my desktop system (due to nearfield listening), but it sounds dull in any other system. They are known to have a high-frequency rolloff. (I didn't find this review until I had purchased mine...and it explains the dull sound.) The tube upgrade did help--I'm running all new-production Mullards in it. Still, not ideal.
No idea why it would do that especially with the adapters you might want to stick with the EL84/6BQ5 tubes. I'm using a JJ EL84 output and a Sovtek 12AX7LPS and the combo sounds great.
This Is kind of cool. I saw a build thread using those and thought it would be a fun build. But at that price I might just order one. I just read another one where a dual triode was used that was made for a tv as well. Only two tubes and 1.5 wpc.APPJ has made five different models which include my S1 ( 4 tube ) , the N3 ( 3 tube ) , the 2 tube ( power supply on bottom ), the 4 tube ( power supply on bottom with same tube compliment as the S1 ) and the latest which is the PA1501A shown below. From all accounts the 1501A is the best of the bunch.