Tell me about "tubey" tubes.


I own pair of Quicksilver mini monos driven by Quicksilver's phono and linestage (A23 transformer and Zu DL103 or Grado Sonora1 mono if you want to swim that far upstream) and a pair of Prologue Sevens driven by a Three and mostly digital sources. Stray speakers follow me home, so I do not voice either for a single pair-- I like rolling loudspeakers. To keep this from becoming a manifesto on that aspect of my illness, I have about "fifteen or so" (I purposely do NOT count them) pair of classic american speakers ranging from various 1970's JBLs, Ohm 3s and 4s, Snell Es and Js, all the Spicas, Klipsch Chorus IIs to the some late-production Maggie 1.6s and Druid mk4s. I do have a few classic japanese high-wattage solid-state systems for those times when current is required, but have fairly sensitive hearing and do not generally need high power to appreciate any of my boxes.

I also run several old 1950's five-tube AM radios and a few Zenith AM/FMs. For radio, I enjoy the tube euphony. I really, really enjoy the euphony.

I'm currently listening to a lot of small-ensemble female vocal, avant-garde jazz, and space age exotica, if that matters.

Both the minis and the Sevens allow rolling of all the usual suspects, and I am aware of the basic sonic differences of power tube types. Both rigs currently utilize stock-spec tubes (2 Shuguang EL 34s and 4 KT88s, respectively), and until now I have not deviated from that. I already know what I need to get fairly accurate sound from both amps.

I don't enjoy tweaking and perfectionism as much as occasionally being whacked in the head by change, which is why I bought self-biasing amps in the first place, and now I'm a gonna use 'em. I want some simple advice: What specific varieties of EL34, KT88, 6550, or equivalents, in your actual experience, would give me the most euphonic, fat, Midrange Uber Alles, tube-colored sound? Feel free to suggest front-end drivers (12AU7/12AX7) as well, if that would make a noticeable difference. Price matters, so current production is a plus. Stick to my two amps. I'll get around to SET one day after I find some K-horns. Experience only, please. I'm not interested in second-hand speculation.
morgenholz
I loved the sound of Penta Labs KT88SC when I had a pair of Mid Monos. They fattened up the bottom end without compromising the midrange. It was a beautiful warm sound. Changing input tubes didn't offer as significant of a difference.
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I would start with the QS phono preamp (I have one)replace the 12ax7 with Sylvania or Ge 12at7. They have less gain but vocals will knock your socks off !
I have rolled quite a few EL34 tubes in the past few years. I find the Shuguang EL34 tube to be fairly sterile. A tube I like that is very cheap and excellent is the 6P3S-E Russian NOS tube (6l6 variant). You would need to check with Mike to make sure it would be acceptable to use in you Quicksilver Amps. You can read up on it on audioasylum.

As far as 12AX7, I have found the Mullard variants to increase the richness of the human voice. Also for less money the GE or Sylvania 5751 tubes will spotlight the midrange.

As always tubes will sound change sound depending on the circuit the tube is installed in.

Good Luck.
Tubey or not Tubey, that is the question.
(I made that up after too much wine...)