Most Musical 6NS7 tube for a Preamp?

I have an XA 25 running with a deHavilland UltraVerve. My volume levels are similar to what you describe.   It is a perfect match for my tastes which are towards tube warmth.  You can roll the 6SN7 to fine tune the sound.  I just this past week rolled from a Sylvania chrome top short glass green label to an NOS black glass oval plate TungSol.  Nice extra is you do not have to worry about matched pairs.  Bass has a bit more punch. Happy before the change and happier now.  Of course, there are so many variables.  In my setup, compared to two prior preamps (an Audio Note M2 and a Vinnie Rossi LIO), the deHavilland is a great match. Both of the other two preamps are very fine products.  It is a matter of how all the variables came together for me.  

Yeah, it’s all about synergy mca_nyc.
I tried the LTA MZ2 which everybody was raving about about 2 years ago and in my setup it sounded broken, flat, boring, 2 dimensional, and lifeless compared to my preamp. I tried all my best tubes but still wasn’t good
I’m not saying it’s a bad preamp just that it didn’t have synergy with my components. IMHO

Yeah @atmasphere, for pre-amp applications, Roger had a hard-on for the 6DJ8 (used in his RM-5 and the Audible Illusions Modulus 2 & 3). He was a man of "firm" opinions. ;-)

@bdp24 We used the 6DJ8 in some our early stuff, since the tube is very linear (which is probably why Roger liked it) and you could get good bandwidth as it supported high currents.

But finding one that wasn't microphonic was really challenging! I often found examples you could yell at and hear yourself in the speaker- and that was in an amplifier!


The 6DJ8 was not intended for audio- it was more for instrumentation (look in a Tektronix 'scope sometime- the tube ones are full of them) and television work. OTOH the 6SN7 *was* designed for audio, and like many products there were hiccups along the way but they did get the design right.  When we started using it the only source of current production was Russia and they were dreadful. But then the Chinese got in the game and their 6SN7s were pretty good! Since then there has been no turning back and we use the 6SN7 in  all of our products.

When we came out with the UV-1, instead of using the 12AU7 (which is based on the 6SN7) as we were doing in our modifications of the Dynaco PAS-3, since we had the room and the current in the power transformer, we opted for the 6SN7 as the centerpiece of that preamp.


What's nice about the 6SN7 is that if a line stage design is at all competent, it will easily keep up with line stages costing a lot more. It does not have to be a complex circuit- in our UV-1 there's only one tube per channel and 4 resistors!


Audio Research makes respected preamps, but I would expect many of the 6SN7-based preamps on this thread to keep up with any of them. This is not an attack on ARC, its simply a statement of how well 6SN7s work in line stages!

Thank you to all for the valuable, informed counsel.

patrick- good confirmation on the newer, Chinese version.

mca-ny- which speakers do you run?

Atma- My reentry to hifi in 2017 has been guided by a now friend
and longtime audiophile. Your comments help to explain why he
put me on the 6NS7 for line stage use.

Great help All!!

I have the UltraVerve and Pass XA25 feeding Focal 1027BE speakers.