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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?
128x128bblilikoi
bblilikoi's avatar
bblilikoi OP
99 posts
 
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.
bblilikoi's avatar
bblilikoi OP
99 posts
 
Art Maltman's observation that the glassiness in my system I thought I was hearing with Svetlana KT88s was not the power tubes but rather the sound of the CD player provoked me to reconsider my entire approach to the issues of warmth and glassiness. Since we exchanged messages in the thread, I've made many changes in my system. I'm still using the Svetlana C KT88s, but I bought a new Cary 303/300 and rolled Mullard longplate 12AU7s into it (replacing stock EH tubes). I've also switched input tubes in my Cary SLI-80 to Bugle Boy 6DJ8s and NOW I have the sound I've been after--a warm midrange with a clear, airy top-end in the massed vocals of choirs. The Bugle Boys are the most recent change, and they replace a whole sequence of fine input tubes (Mullard 6DJ8, Siemens & Halske 6DJ8, Philips 6922 SQ, Philips 7308, Mullard E188CC/7308)--all very good, but not as airy and spacious as the BBs. Art Maltman's observation that I may have been describing the sound of the Cal player rather than the KT88s was entirely correct--it was the CDP that was the limitation of the system (also with JoLida, Lector 0.6T, and Modwright Sony 999ES). I decided to upgrade my target price-point therefore, and I couldn't be happier. His suggestion/criticism/observation was the critical point at which I began to reconsider my approach, and the resulting chain of changes has given me a system that pleases me a great deal. [As a side-note, I want to mention I've acquired a quad of 50s Tung-Sol 6550s that are wonderful with operatic voices, especially with lyric sopranos; and I have also read that Western Electric is planning a re-release of the Genalex KT88 once made by Marconi-Osram.] Many thanks to all for your feedback. It's a perfect demonstration to me how well Audiogon works as a site for hobbyists who seek help and then, like magic, receive it.
artmaltman
769 posts
 
I'm thrilled to hear how things are working out for you Bb. Of course now I need to try Bugle Boys in my Cary SLI-80!
Art
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