Which KT88s for Cary SLI-80?


I'm shopping to replace the output tubes to my Cary SLI-80 and have been recommended several new production KT88 tubes--JJ Tesla, Groove Tube, and the Electro-Harmonix EH tubes. I notice Cary has the Electro-Harmonix tubes in their F1 premium model. I've been using Svetlana "C" KT88s with good results, but I want to warm the midrange and sweeten the top end. I play mostly classical music--Renaissance choral, Romantic Italian opera, and symphonic orchestral music. There are complex and massed trebles in these all the time that make for difficulties. For example, I tried using Siemens/RFT EL34 tubes, which created much more air and spaciousness, but they also seemed to lack enough power to negotiate these complex massed treble passages--choral voices, unison violins, etc. The system presented an edgy glassiness at the top that masked all other details at dynamic peaks. This doesn't occur with the Svetlana KT88s, which also have more focus, but I'd prefer more warmth, body, and air in the music if possible. My other tubes are Mullard CV378 rectifiers, Brimar 6SN7s, and Mullard E188CC/7308s. I use Audience Au24 ICs and speaker wire, an CAL CL-15 player, and Sonus Faber Grand Piano Home speakers. Suggestions? Characteristics?
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Thanks to all. I have heard of the JJ Tesla KT-77s as an EL34 alternative. When I was trying EL34s (which turned out not to have enough power for my system's needs), a dealer suggested I try the KT77s. I'll go back and look them over, see what the power ratings are. If I use the lower-powered tubes, I can perhaps compensate by switching the amp to ultralinear mode, which allows for more power though it usually doesn't sound as good as triode. Regarding the issue of KT88s--Cary ships this amp with the Electro-Harmonix tubes and I've heard some on their staff (and Kevin Deal of Upscale Audio) likes them a lot. I'll call them Monday for a view. Very nice of all of you to respond with your suggestions.
I think you are describing the sound of the CAL cd player, not the amp! I did not own the model you own but I owned several others and while they were great in their day, over time they sounded mechanical compared to newer models. That was my experience anyway.

Art
Aloha Artmaltman! Actually, I had the EL34s in the Cary while using three different players--the CAL CL-15, a Modwright Sony 999ES (Tung-sol tubes), and a Lector 0.6T. The edginess/glassiness occurred with each of them (though less so in the CAL than the other two), which is one reason I thought to switch back to KT88s in the Cary.

Regarding power tubes, I've spoken with one dealer, eurotubes.com, who said emphatically the KT77 JJ Electronics tubes ARE NOT "JJ Tesla" as I have been used to calling them, but are made in Slovakia in a factory using some old Tesla equipment. He also said that the JJ Electronics E34L is the tube with more power--about 15%-20%--than the EL34 and not the KT77 they make, which is based on a GEC KT77 and has the same power rating as an EL34. I'm just reporting his comments, though, as I have tried none of these.
Have you tried the Svetlana's EL 34? The EL 34 produces a warmer sound than the KT 88. I have Prima Luna equipment and have just switched from Svetlana KT 88's to their EL 34's. It is a bit warmer and more intimate sound ... very pleasing.

Regards, Rich
I've tried Chinese EL34s (stolen from my own PrimaLuna One) and RFT EL34s. I wouldn't say those were warmer, but they did create interesting changes in spaciousness of sound and air--particularly the RFTs. Like I said above, the drop in power also caused glassiness in massed trebles, so I switched back to Svetlana KT88s. Kevin Deal, though, of Upscale Audio gave the same recommendation regarding warmth, as he says the Svetlana Winged "C" KT88 is the warmest of its kind and the only way to improve on it is to go to Svetlana (SED) EL34s. Thanks for the view.