Jolida jd-502p

The 5751 is simply a lower gain version of the 12AX7. It will not do any harm in the circuit and is a direct replacement.

Like it better? Only you will be able to make that decission.

Thanks everyone for your responses. I did get a chance to
hear a pair of RCA JRC- 5751WA the sound was was nice and open with a good sound stage and nice separation but very little bass.In other peoples experience do the 5751's typically lack bass. Is there another tube that I might try to get a little more bass?

Try the GE TM gray plate 5751 from the 50s. The bass is prodigious in my experience and several friends as well. The Sylvania 2 mica Gray Plate 60s tube also has more bass than the RCA BP. As far as 12AX7s go you will prolly have to go with true Mullard Blackburn long plates "IF" you can get decent ones. They seem to emphasize bass. Failing that specific tube try any other older Mullard production.

Hi Wilson667

What 12AX7 or 5751 tubes did you get to replace the existing 12AX7 tubes in your JD-502p? Also is your JD-502P the stock or upgraded one from Jolida?

Thanks

Jedinite24
I am still not settled on what 12ax7 to use. Shortly after this thread my phono pre had to go to the shop. It was and still is my only source and does double duty as my preamp . I did not get to listen to any music other than through my tv.Now that it is back I hope to get this sorted.So for now I am using some sovteck 12ax7 the tung-sol that came with it and a rca jrc 5751wa of those I think I like the sovteck best.

I bought my 502 used here and the person I bought it from did not say if it was upgraded and I did not ask.So shrot of opening it up I have now idea how to tell.Sorry I could not be more helpful.