2. amps-preamps
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12ax7 12AU7 EL34 / KT 88/ 6550 upgrades for PL2

I acquired a used primaluna prologue two a month or so ago. This is my first experience with tube amp. Coming from rotel amplification I am just wowed with the tubes. The PL2 had upgraded tung sol 6550s. Nice sound. But I changed to new issue Electro Harmonix H EL34EH. Ran-in the tubes two days straight with music. Was simply blown away with soundstage and tone! Guitar riffs and blues sound gorgeous! Bass isn't too shabby either. Quite enjoyable.

Then found a little more improvement by switching 12ax7s from stock to Electro Harmonix ($10 bucks each).

The tried changing out 12AU7 with some old used tunsol 5963/12au7 (made in the USA) and was not happy. Changed back to stock.

Does anybody have any good experiences with upgrading the 12ax7/12au7 and power tubes on the PL2. I would appreciate the advise. Tube rolling is so much fun!

My speakers are quad 22L2, cd player oppo bdp 83se and analog source is MMF5 w/ MMshure ML140E.
rohitdev

Showing 2 responses by thehub

thehub's avatar
thehub
11 posts
 
I just purchased 2 matched sets of the Psvane 12AU7s from Grant Fidelity and got them installed today in my Cary SLP 03. My Cary 120S amp will be delivered Monday from Cary. I sent it in to get the MK 2 revision. It has all Shuangung Treasures in it (KT88 & CV181-Z) which are broken in with about 400 Hrs. on them. It should be interesting and I will post an update ASAP. The Psvanes are replacing TJ Full Music 12AU7s because one tube got loud. The sound was good but reliability is important to me. I am gonna sell the 3 TJ's cheap if interested.
Dave
thehub's avatar
thehub
11 posts
 
I have had the Amp (Cary120S Mk2) back from Cary for about three weeks now. The improvements are clearly audible and very pleasant. My impressions so far would be that the upper end is a tad bit leaner (by no means dry) with a tremendous amount of air surrounding instruments such as cymbals, bells and triangles. A cleaner, deeper view into the soundstage. Dialog has been improved to the point that you can almost see the expressions on the singers face as they finish there lyrics, a greater understanding of the music. The Amp now has 28 db of gain and is very easy to drive. The magic in the Midrange and Bass has been improved also. Female vocals and Piano are stunning!
My only regret is that I can't tell you how much the Amp revision or the Psvane 12AU7 tubes contributed to the improved sonic quality.
I was listening to an old Richard Goode (Who I had the pleasure of attending one of his concerts in Carnigie Hall) CD of Beethoven Piano Sonatas a couple of days ago and the Wife asked who it was? She said the piano sounded very nice, like a real piano in the front room. That blew me away as she very seldom comments on any thing I play except to say "Turn it Down!"
My system consists of Harbeth Compact 7 ES3 speakers, Cary Preamp SLP03 and Cary Amp 120S Mk2, and a Sony XA5400ES SACD with Harmonic Tech. Magic speaker and interconnect cables.
As mentioned above the Amp has KT88 and CV181-Z Shuangung Treasures and the Preamp uses Shuangung Psvane 12AU7s.
If I get good life out of the Psvane tubes (yet to be seen) I will continue using them and as of now can recommend them highly. Dave
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