Tube upgrades for Jolida 502B?

I stuck KT120s in my Jolida 502p after being assured (By the Jolida MD people) they would work. They do. Amazingly. The stock 6550s were fine, as are the Sovtek KT88s I tried, but the 120s just sound better in every way I can hear. Then, it was suggested by a dude at the tubestore.com to try their "preferred" 7025s in place of the 12AX7s...another brilliant idea that, combined with the 120s makes the amp just sing...more accurate seemingly, crisp but still tube rich...all good, and the 120s hold the bias settings really well. Now I'm thinking of trying Mullards in place of the EH 12AT7s and if that makes things even better, my head might explode from happiness.

Hi Tbromgard

Another Jolida JD-502P owner chiming in here. I too have Tung Sol KT-120 power tubes installed on the 502P and am very happy with them. Out of curiosity I did try the a matched quad of solid black plate Penta KT-88SC tubes. I found the bass to be less tight with the KT-88SC tubes vs the KT-120s. Mids and Highs were slightly better with the KT-120s to me. I may keep the Penta KT-88s since they don't come up for sale often or if I want a change of pace.

Now for preamp tubes here is what I've found in my system. All these notes were done with the Tung Sol KT-120 power tubes in place.

With a mellow source I found Penta Labs 12AT7 tubes and Groove Tubes 12AX7 Gold tubes make for better detail in the music without any listener fatigue.

With a source that is very forward I found The Preferred Series 7025 tubes along with Tung Sol 12AT7 tubes made the music more warm and mellow in my system with just the right amount of detail.

I also found the re-issue Mullard 12AX7s along with the EH 12AT7s made for a very mellow less detailed presentation to the music in my system. A lot of songs I was playing were really laid back. Maybe it could have been revealing the true mellowness of my source but that is what I found.

Best of luck with the search.

Thanks for the tips guys. Any other experiences tube rolling with the JD 502B?

You might want to confirm with Jolida but to me the only difference between the 502B and the 502P is that the 502B has volume, input controls and subwoofer output. Other than that the Amplifier section is the same.

I have to wonder what difference better 12at7s would make as I have been told that particular tube purpose (driver/phase inverter) is somehow less important. I welcome any opinions about that, as long as they aren't meant to intentionally upset me.