What made you change to a 6SN7 preamp?

@atmasphere 

when you dig into it you find out that the variables I mentioned above were uncontrolled in the comparison. 

Your understanding of these variables, and your cautious way of taking variables into account when you make comments, make you an invaluable voice in this forum. Thank you.

Lack of control over variables is what leads discussions into sometime wild and fun or confusing and conflictual directions. Of course, the room is almost never mentioned as a variable in almost any discussion, but that of course is a hard one!

The only tube pre I have owned is 6SN7 tubes. I am happy enough to not look further. I have rolled tubes and right now nos  Sylvania bad boys sound great. My holly grain is an old pair of telafunkins but not willing to pay $500 per tube right now. Hear a lot about mullards and will be trying them next. What I have noticed is after about two hours of warm up the sound stage opens up and it is total bliss!

"Unrelated to the thread topic but important to those looking to optimize their purchases regarding NOS tubes, Andy @ Vintage Tube Services is the guy. Give him a call, you’ll be rest assured he knows his tubes and upon ordering you’ll also find yourself grinning from ear to ear. He’s a passionate and perfectionist audiophile."

@tubegroover I did order some 12au7s and 6922s (Mullards and Amperexs) from Andy over 20 years ago and he did make me laugh. He had some strong opinions about manufacturers that wouldn’t be fair (to those manufacturers) to share. About 7 or 8 months ago I upgraded my 12AU7 pre to a 6sn7 pre, and I am about to upgrade the tubes. I have been putting off my decision of who to buy the tubes from, but I guess I’ll give Andy a call on Tuesday.

I am running a Musical Design Chameleon preamp made by John Hillig.  The same well known and respected person that has made many people ecstatic with their systems.  The Chameleon has several daughter boards that snap onto the motherboard and provides an easy way to compare differences in tubes and tube types.  I find the 6sn7 board with my Tung-Sol 6sn7GTB provides a good soundstage and a rich tone that you can listen to for hours.  I swap different boards and tubes.  Presently I am using a board with 2 Telefunken 12au7 tubes.  I really enjoy the outstanding sound and flexibility this preamp provides.

@sjackso1 "...I find the 6sn7 board with my Tung-Sol 6sn7GTB provides a good soundstage and a rich tone that you can listen to for hours. I swap different boards and tubes. Presently I am using a board with 2 Telefunken 12au7 tubes. I really enjoy the outstanding sound and flexibility this preamp provides."

This is an interesting ability to compare the two tube types using the same preamp.

Are you utilizing new "re-issue" TS 6SN7GTBs to compare to vintage Telefunken 12au7s?