I thought the Ken Rad, Sylvania Bad Boys, were my favorites. if you can find some that are not "microphonic"..
I seriously doubt it
I got them from Andy @vintagetube services.
The problem with all 6Sn7s is that they do not have that great of bass, well except for The Ken Rads ... good luck. I even outright told Andy that i wanted some 6SN7 with good bass,,, It ain’t going to happen.
Now depending what other tubes it uses , you can get those with better bass and make it up. As an example my amps used one tube 6SN7 for the phase splitter and another type for the gain like maybe 12AT7.
Oh BTW the Sylvania bad boys do everything top notch...except Bass.
It is there . It just isn’t that strong
Check this out from Electra Fidelity
http://electrafidelity.com/tube-rolling
I copied and pasted it below:
A WORD ABOUT 6SN7 TUBES
As for 6SN7 tubes the circuit of the Silver 45-SE offers more flexibility, but again, some of the 6SN7 variants (especially those not designated with 6SN7 markings) may not work ideally in the circuit as it was originally designed. However, in our own testing and analysis we have found that for our preferences and best sound characteristics the Raytheon VT-231 with black flat plates (or alternately Raytheon 6SN7GTB, either short glass envelope with side getter or tall glass envelope with top getter) is the tube of choice. Next would be the Sylvania VT-231 with black plates (or alternately Sylvania 6SN7GT with medium glass envelope, black plates, and bottom silver getter, a.k.a. "Bad Boy"). Lastly the Tungsol 6SN7GT with black glass and round mica, a.k.a. "Mouse Ear", work well in the circuit.
Recently one of our customers did extensive testing of different 6SN7 tubes in the Silver 45-SE. Click HERE to view the 6SN7 tube analysis. So as you can see, many different sound characteristics are possible, all due to the different electrical and, perhaps more precisely, distortion characteristics of the tube.
As with the 45 tube types, if you have any questions regarding tube rolling and which 6SN7 tubes are acceptable replacements for the ones supplied with your amplifier, please contact us and we will be happy to discuss options with you.
This the link he had providedhttps://www.head-fi.org/threads/the-reference-6sn7-thread.117677/
Good Luck . Personally, I wish amp/pre-amp Builders would quit using them ,
Wow,
This about exactly what i thought .
this is probably the nest IMLO
http://www.enjoythemusic.com/magazine/equipment/0304/6sn7.htm