Tube preamp for SS amp

6922, 6H30 or 6SN7 decisions decisions. What sounds good to me might not sound so good to somebody else....I get it, but is there a tube preamp/solid state amp that is not a good match sonically (running a pass labs x250.5 and bryston 4bsst2). I can drive 2hrs and audition some ACR equipment however that's it. Everything else would be purchased out of state and most places will have to special order something else in (ie modwright ls100, cj ET3SE, audible illusions...) and will only take the equipment back for store credit.

chad263512-24-2013 4:39am

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lowrider57 Details Discussions Posts This discussion Message User 5,393 posts 12-25-2013 at 02:05am Copy Comment URL Report Comment Edit Delete Rogue Audio has preamps which offer low output impedances, low enough to mate with SS amps. The Athena has an output impedance of 220 Ohms, the Hera II output is 120 Ohms. Gain is 12dB single ended, and 15dB Balanced.
charles1dad Details Discussions Posts This discussion Message User 10,230 posts 12-25-2013 at 02:24pm Copy Comment URL Report Comment Edit Delete Hi Chad, You ask good questions that are tough to answer. As you noted there are many variables to consider with all things in audio. I'll give an admittedly general impression based on personal listening encounters. The 6H30 tube tends toward a leaner tone and body character. Some would say neutral and accurate sound ( and call it "solid state like") . It doesn't appeal to me as the sound is flatten and clinical, it isn't organic and loses emotional communication. If built -implemented to a high quality standard I'd rather have a 6sn7 based preamplifier, better sound, fuller and more realistic tonal color, weigh and vibrancy. Just comes closer to my experience with live sound compared to the 6H30 examples I've heard (which obviously isn't everything out there). I've also heard good sound with 12x7, 6922 based preamps as well. My top choice is a preamp that uses DHT(directly heated triode) type tubes, but that's just me. Charles,
almarg Details Discussions Posts This discussion Message User 9,670 posts 12-25-2013 at 03:29pm Copy Comment URL Report Comment Edit Delete Depending on your budget you may want to consider the Atma-Sphere preamps, which btw include (I believe optionally) what is by all accounts that I have seen an excellent built-in high gain phono stage. My understanding is that they would have no problem driving any amplifier in existence. They are also fully differential, which would be complementary to your Pass amp. They use 6SN7 and 12AT7 tubes, and also 12AU7's in one model. Regards, -- Al
rx8man Details Discussions Posts This discussion Message User 1,475 posts 12-25-2013 at 08:19pm Copy Comment URL Report Comment Edit Delete +1 for Charles1dad, we're on the same page.
tomcy6 Details Discussions Posts This discussion Message User 2,538 posts 12-25-2013 at 11:01pm Copy Comment URL Report Comment Edit Delete Just to clarify, the input impedance of the amp should be at least 10x the output impedance of the preamp. Tube preamps can have fairly high output impedances, e.g. 1.5 kohms. 10x this output impedance would require an input impedance of at least 15 kohms for your amp. That's a pretty low input impedance for an amp, but they are out there, Pass Labs for example. Many SS amps have an input impedance of 47 kohms or higher and you should have no problem pairing a tube preamp with one of these amps. Try to find a review with measurements of the tube preamp you are interested in because manufacturers give a nominal output impedance with their specs. The preamp may hit a significantly higher output impedance at certain frequencies. This question comes up often and there are a number of threads on this subject you can browse for that will give you recommendations for specific combinations.