I use Genalex KT77's in my Prologue One. Very happy with them. Tried KT66's, but was not impressed with them.
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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.
To the Op, thanks for asking this question as well as your well written description of your experience with the Primaluna Dialogue One. The tubes I have used the most and have championed is the Russian NOS Reflecktor 6n3ce, 6L6 tube. I first heard about them in a blog by Jeff day who did a tube shoot-out for his Leben CS600. This tube beat, according to Day (a pastreviewer for 6 moons, currently Positive Feedback) all comers in his system.
My brother who also owns a Leben CS600, decided to try them; his speakers are Harbeth HL5. We had our own tube shoot-out party with a half dozen friends. This tube is inexpensive ($65 a quad) and is a little short and ugly like me; but, boy could they play music, solid across the board. I think we created a mini-run on these tubes from Jim McShane, who had a good stock, now mostly out. They are hard to come by.
I have rolled many tubes in and out of my Dialogue One. My least favorite tubes were Shuguang and Ruby KT66s that I liked very much in my Cary V12. They were lifeless and dull in the Primaluna. Oh, forgot to mention that my speakers at various times have been Infinity Prelude Compositions (a vastly underrated speaker 96db with built in 12 inch sub driven by 300 watt internal amp), Tekton Lore, Tekton 4.5, on loan from brother, the Harbeth HL5, Vandersteen 2ce, 1C. I also recently bought the Tekton M-Lore and sold the 4.5.
It's important to note that, like you, I concur with your KT120 comments. I've heard good things about Tungsol newish coke bottle EL34s and plan to give them a go very soon. In EL34s, I've really liked the SED Winged C. To keep this short I will say I generally like the EL34 sound/tone for the reasons you already stated. My room is really good, 16x14, 9 foot ceiling with peak to approx 12 feet. Wall to wall on most recordings, natural height and deep layered soundstage if it is in the recording. Jazz, Classical, Rock, none has been problem.
Associated equipment generally:
MIT Digital to Eastern Electric DAC with Black Treasure 12au7
PS Statement Speaker Cable as well as Kimber 8tc or Goertz AG1 Silver
Sony DVP S9000ES as transport
BPT Power Conditioner
I installed NOS Bugle Boy 12au7 and Sylvania 5751Black 3M. Other tube sets sound good but these tubes are best for me.
I use a Dialogue2. I replaced the stock KT88s with some EL34s that I am much happier with. I will say, though, that I agree the stock tubes are not nearly as bad as some say. In fact, I had to replace my stock 12AU7s recently, and I went with a more familiar brand which I am very sorry to say is not as good. I will order the stock ones next time.
Schubert, I bought a couple of spare pairs, perfectly matched, cost about $235 per pair. For me, best 12ax7 equivalent out there. I also liked the GE 5751s 3m. Im really glad I bought the spares. I also recently bought the black treasure 12ax7s from Grant Fidelity, not bad, but Sylvania, much better.
I use PL mono 6 amps with KT-66s. I've tried at least one example (usually two or three) of all suitable output tube types in these amps. While Merlin recommends EL 34s (and they do sound great) I marginally prefer the Gold Lion KT-66 tubes with my VSMs. To my ear, you trade a little mid-range lushness for slightly improved dynamics and a bit tighter bottom end.
As usual, YMMV (particularly if you're using a different loudspeaker).
Another vote for (EH) EL-34's . Better by far than the KT-88's that came stock . My Prologue II is driving Ref. 3a Di Cappo i's .
Have you tried rolling the input tubes ? They can make quite a difference .
My Prologue , stock , sounded quite solid statish to me . Not really much of the traditional tube sound that I was seeking . Now it is a whole different sound .
What are you trying to accomplish with a tube change ?
Thank you all for the feedback. I'm happy to read that I'm not the only one preferring the EL-34 sound, nor the stock Prima Luna tubes, which seem to be a lot better than folks give them credit for.
I did run into a little bit of a dilemma, though. When I switched from the KT-120's back to the amp's stock EL-34 tubes (and after I collected my jaw from the floor and kicked myself in the head for having sacrificed all that sweetness, midrange magic, openness and transparency for so long), most of my listening was done using the digital side of my system (an Oppo 95 playing mostly FLAC and hi-res files from an external drive, and SACDs via Nordost Heimdall interconnects). This combination sounded simply glorious. All the usual attributes of the EL-34 sound were there, but bass was also abundant and tuneful. It wasn't as tight as with the KT-120's, but nor was it excessive or bloated. In my room and with my speakers, it was simply JUST RIGHT. My digital "front end" never sounded better! In fact, it never sounded this smooth and analog-like. I could listen to this combination for hours and hours, and that is precisely what I have been doing lately.
BUT, when I finally decided to listen to some vinyl (Pro-Ject RM 5.1 SE table with Dynavector 10X5), the synergy was not as magical. In short, for whatever reason, unknown to me, the bass is considerably weaker now. Tight, ripe and alive using digital, and yet VERY limited in extension when switching to analog. Low bass is almost NON-EXISTENT. My Sonus faber Toy Towers now sound like terrific monitors instead of 3-way (almost) full range towers. The midrange magic is there more than ever, but I'm missing the foundation. Phono pre-amp is a Pro-Ject Phono Box S. I triple-checked all the settings and nothing had changed since the last time. I have to say that the KT-120 and KT-88s were a better match in this case, particularly since I listen to a lot of 70's rock on vinyl.
So, now, of course, I miss my Gold Lion KT-88's. I know the 120's are NOT for me (too harsh and bright, too "solid-state" for digital), and if anything these last few days serve as confirmation and reminder that I am more of an "EL-34 type of guy". But I listen to vinyl a lot and now there's something not quite right with this tube and my table/cartridge combination. Digital sounds like analog and analog sounds TOO soft and with no real "bite". I REALLY, REALLY love the Prima Luna with EL-34's and my digital front-end, but I am torn as to what to do to aid bass extension when listening to vinyl. I might have to give the Gold Lion KT-88s another try, hoping NOT to loose much of the beauty of the EL-34's in the process.
Could any of you folks with similar experiences share your thoughts, try to explain to me WHY such a huge discrepancy in overall presentation is apparent between digital and analog, or recommend an EL-34 that that has a little more of a pronounced and ballsier low-end? Thanks in advance.
Well, the quest for the perfect output tube for my Prima Luna DiaLogue One and Sonus Faber Toy Towers combo, as futile as it may seem, continues. You can read more about my experiences with different tube types and brands in the previous posts in this thread.
I am now burning in a new matched quad of Electro Harmonix 6CA7s, the consensus about this particular tube being that it is basically an EL-34 on steroids. Almost all of the midrange magic of a traditional EL-34, but with more bass. That was certainly the case when I first installed them, and while I listened for the first few hours. In fact, I was astounded at the amount of bass energy. Tight, deep, extended, sometimes more so than with my Gold Lions KT-88s! I was in heaven for an hour or two and thought these were keepers. I thought I had found the perfect tube type for my amp and tastes.
BUT, after about 20 hours or so, the bass is weak, not as extended, nor tight, etc. Just like with the Shuguang EL-34s. And the midrange not as sweet, so it's kind of a "worst of both worlds" scenario. I now remember going through a similar experience with the factory-installed Prima Luna EL-34's. They seem to sound INCREDIBLE at first, but loose their grip and "slam" factor shortly after. Don't ask me why. I am puzzled. Could it be a voltage issue? I live in a condo, so I'm sure the quality of our electricity here is not optimal, yet every power conditioner I have tried made things worse. Highs can be harsh and piercing sometimes as well.
Could it be the Prima Luna auto-bias circuit acting up? Or the tubes going through some sort of phase as they break in? Or could it be me? Those days where the stars align and the system sounds JUST RIGHT seem less and less frequent now.
Any ideas about why a quad of power tubes (brand new) would offer plenty of bass extension and midrange sweetness when first installed, and loose some of that tightness, grip and beautiful tone shortly thereafter?
I use KT-120's in the Prima Luna Premium integrated. GL KT-88's sound artificial in comparison and EL-34's are mid range tunnel vision. Front tubes used are all Telefunken 12AU7. The KT-120's remedy the PL integrated review crticism of diluted bass and provide excellent transients with full range response.
However my caps are not stock as I view Solens that come stock with Prima Luna as inadequate, irritating. Using Rel film caps.. teflon and cu caps in the pre section, theta in the power section.
Rekindling an older thread as I recently had a lot of fun with a good ol' fashioned tube shootout with my Primaulna Dialogue Premium (which I'm just running as a power amp through the Home Theather bypass right now).
I had a lengthy shootout, with many different songs and types of music, with the stock EL-34s, a set of KT-120s, an NOS set of RSD (RFT) "Siemens" EL-34s, and a set of PSVane 6CA7-T tubes. I burned in the KT-120 and PSVanes for about 60 hours each before doing any serious listening.
Honestly, to my ears, it was easy to narrow it down to the RFT Siemens and PSVanes, and from there it was difficult to choose between them.
The stock tubes don't sound bad at all, but head to head with the other tubes, the bass was a little loose and flabby, and the midrange a little thinner. I also did not love the sound of the KT-120s. I know I'm in the minority on that, and the bass was nice and tight, but I thought there was a little something missing in the midrange and slightly tinny on the high end, in direct comparison to the NOS and PSVANE tubes.
I did a run-off shootout between the NOS RFTs and the PSVANES, and went back and forth about 20 times as to which ones I preferred. I ended up going with the RFT Siemens. Although the differences were very subtle, at the top end the RFTs were ever-so-slightly more forgiving of my less-then-stellar recordings. But I could have lived happily with either of those forever.
Overall it was a fun experiment and now my system is sounding even better! By the way, quads of the NOS RFT/RSDs can be found on ebay for about $160, so they are one of the better values for NOS EL-34s in my opinion, but you do need to look closely at the pictures and look at the feedback and make sure they're the real thing.
I recently did the same shootouts between the RFT Siemens and Black Treasure 6CA7s. In the Dialogue I like the RFTs best so far. In my Coincident Dynamo 34se I prefer the Black Treasure 6CA7 even though they are still breaking in. I have used Gold Lion KT77s as well, but they rank lower on the list to my ears.
Very interesting, Mikirob. What differences did you find between the Black Treasures and the RFT Siemens? I felt like I was splitting hairs a bit to hear much of a difference at all, as they both sounded great, but as I noted above, found a small difference in the high end. I'm curious what areas you found to be different as well.
In the Primaluna Dialogue 1, like you, I thought it was splitting hairs. Ultimately I believed the RFT Siemens ever so slightly had a fatter tone and was smoother on top. The Black Treasures had better bass, more extended on top, very slight etch on some recordings, but I expect this to smooth out over time as these tubes break in. The mids on both were superb.
On my Coincident Dynamo 34se (8 watt DHT) it was no contest. The BlackTreasure 6CA7s were definitely superior in every parameter. The Coincident has a 60s Mullard 5ar4, Jan Sylvania 6slt. The Primaluna has NOS Bugle Boy 12au7s and NOS 5761s. They affected the sound the most over stock tubes and other brands.
I really like the Reflector NOS 6n3ce tube (6L6) in the Primaluna as well.
Thanks. Very interesting, and also good to know that I wasn't completely crazy. At least not with respect to this particular shootout.
I'd like to try out a Coincident amp in my system someday. I can seem to find nothing but universal praise for them. Right now things are sounding quite good, though, and someday I'll have to figure out how to just relax and enjoy the music for a while!