PRIMA LUNA owners, what power tube are you using?


To all Prima Luna owners, specifically those with a DiaLogue One integrated amp (although owners of the new Premium amps and the ProLogue series are more than welcome to chime in with opinions and feedback), which power tube are you currently using? Which others have you tried in the same amp, and what made you prefer the ones you ended up going with? And, of course, please specify what speakers you are using the amp with.

I own a DiaLogue One myself. Happy owner for close to 4 years now. It comes standard with EL-34's, and it's, in fact, designed for that specific tube. But Prima Luna amps are a tube-roller's delight, and the manufacturers encourage trying other types.

Personally, and after experimenting with the Gold Lion KT-88's and Tung Sol KT-120's, I ended up going full circle and back to where I started: the stock EL-34 tubes. These are labeled as "Prima Luna", but are actually made by Shuguang in China and, supposedly, only the best rated ones end up being used for the Prima Luna amps.

My system consist of the DiaLogue One, Sonus Faber Toy Towers, and Oppo 95 for CD's, SACD's and digital files (mostly hi-res and FLAC files sourced from an external drive), Pro-Ject RPM 5.1 SE with a Dynavector 10X5 for analog, and Nordost cables all around (Brahma PC, Heimdall and Red Dawn LS interconnects, etc).

My journey could basically be described like this: I started with EL-34's, loved the sweetness, transparency and midrange magic but needed a little more grip on the low-end (and also detected a hint of harshness in the upper highs from time to time), so I switched to the re-issued Gold Lion KT-88's. The Prima Luna auto-bias feature took care of the rest. I LOVED that combination (and loved the way the Gold Lions LOOK, as inconsequential as that sounds), but reliability was an issue. One exploded while in use, and the rest would loose their sparkle and life in less than a year, with moderate to low use on the amp. At $200+ per quad for tubes that don't even last a year, things get expensive really quickly, so I needed an alternative.

I then tried the KT-120's that everybody was raving about and that were actually cheaper than the Gold Lions. Originally, they were not my cup of tea. Too aggressive and bright on the one hand, but not that much different than the Gold Lions when it came to added bass grip and control. I actually gave them a second chance, burned them in for at least 200 extra hours and they definitely got better (less harsh on the top, rounder in the mids, but, again, with no extra "grip" gained on the bottom). Still, the magic was just not there and my amp was never designed with that tube in mind anyway, so why even bother?

I then went back to the stock EL-34's that I still had sitting in the closet. These were not as "sweet" and "magical" as I originally remembered them, ironically, offering bass aplenty (albeit looser, slightly sloppier bass, a quality that for some reason I tend to like on most material since it seems to allow the music to feel more tangible, less sterile and artificial), and an incredibly more open, extended and detailed soundstage, which definitely got "wider" and more STABLE when compared to the KT-120's. With the emphasis being on the mids, there's a lot of details to be gained that were perhaps a little obscured by the more linear characteristics of the KT-88's and KT-120's. Notes in the upper-lows are now considerably more clear and I'm simply hearing a ton more music in the bass and low end. Yes, the KT-120's were sturdier and allowed my Sonus Faber Toy Towers to go a little lower, no question, but at the expense of detail and finesse, I believe. This translates into a significantly more "crystalline" presentation, with the well-known musicality and ripeness of the EL-34 in place, and one that I am finding myself preferring. It all works wonders with jazz and classical, particularly with strings, but rock albums actually sound more vibrant as well. Certain passages tend to break up a little bit, but oddly enough this only happens with very few instances of highly distorted guitars and/or very, very complex passages on extreme metal albums (a genre I also love). Overall, though, I think the EL-34's are back and staying, at least for now. Next experiment: the Gold Lion KT-77's. Anybody have any experience with them?

Would love to hear about your own experiences.
beyondarkness
I use Genalex KT77's in my Prologue One. Very happy with them. Tried KT66's, but was not impressed with them.
I have the Primaluna Dialogue II. The first day -- being so disappointed with the stock KT 88s and supporting tubes -- I bought NOS Mazda and Telefunken and -- more to your point -- a matched quad set of Bendix 5992. These 5992s have extended the 3d sound scape that the Mazda and Telefunken tubes create. The Bendix tubes are on the very pricey side but they are also present in less expensive labels. In addition, when new these tubes glow a deep purple color. I have run this NOS tube complement for two years now and I have never looked back. SACDs sound outstanding and vinyl sounds out-of-this-world.
I use Tung-Sol EL34B, and I'm quite satisfied. Since I've had them for a long time now, that's a testament to their longevity.