Driver Tubes 6922

@vthokie83

”There are dozens of versions of the 12AU7/6DJ8 family…”

these are very different families not compatible for a gathering…one is 12v the other 6v to begin with..Also, the op does not discuss or use 12au7??

@tonydennison 
Just my take using them in 2 Amps, phono pre and a second DAC.
So many…so little time and $…Cheers!

12AX7

RCA ‘50-60’s long blackplates (fav)

Mullard 50’s-60’s long plates (close 2nd)

Sylvania ‘50-60’s long blackplates

Amperex 50-60’s long plates or early short plates with large O getter

Telefunken smooth or ribbed plates (less warm)

12AT7

Mullard ‘50’s square getter (fav but rare)

RCA and Raytheon 50-60’s black plates

Brimar 50-60’s Yellow(rare) or white T series

Tungsram or Telefunken (less warm)

Depends on the amount you are willing to spend?  I have a Lab12 DAC 1 Reference that takes 2 6922’s. I prefer old stock tubes on the warmer or neutral side with detail.  My experience rolling:

$- Amperex Bugle Boy 6DJ8 Holland (excellent value with great SQ)

$$- Amperex 6922 Holland

      Amperex 6922 USA

$$$- French Phillips E188cc/7308 labeled RT, RTC, Dario Miniwatt,Mazda=My Fav

        Amperex 7308 Holland (or USA) SQ or PQ label best

        Siemens E88cc/6922 Germany (little brighter)

Talk to and look at Brent Jessee and his website.  Very helpful and informative.  Good luck with it all.  Tom

@tonydennison Kentucky Radio made some excellent tubes.  I had ‘50’s 12ax7 blackplates.  They sound excellent but harder to fine and can be pricey.  I prefer the RCA over them.  Ken Rad made some pewter plates in the 50’s that are even better but I never had any. Ken Rad was bought by GE so GE 12ax7 grayplates from early 60’s are really nice and an exceptional value if cost is a concern.

The order of best impact for me would be the order you listed but all are important.  Cheers!

@tonydennison just curious where are you buying your tubes from? 

@tonydennison one more suggestion that may or may not work out.   I have had excellent results using 12at7 and 5751 tubes in place of 12ax7’s.  They are identical except the gain is lower than the AX’s. (You can go down on gain with these tube types but not up) I have used them on a DAC pre, phono stage and can’t tell a difference and they sound great. Not sure if your mono’s need the extra gain or not. 12AX7’s are becoming much pricier and harder to find now.

Excellent trusted resource to buy tubes.  Cost a little more but you get what you pay for!

@tonydennison yep once you go NOS you never go back…yep that is a failed tube and do not use it to avoid any shorts that could impact your pre.  Brent has a guarantee and will replace it or them.  Old 40-50’s black plate RCA most tube types are fantastic 12at, 12ax, 12au, 6sn7, 6l6….my favs.  I have only had one tube fail on me.  It was a ‘40’s radiotron tube that came with a new preamp from australia.  Tough long trip I guess.  On my second use it had a very loud static then  pop and became a rattle.  

@tonydennison NOS in my view is testing at new level or above used or new.    Tubes age with time even in boxes and handling.  Pins slight bent are normal for used tubes.  Brent tests all tubes with great equipment.  Just a one off is my take.

I have some extra tubes you can try out if you want to see how you like different ones.  Just personal message me if you are interested.  I’m not a seller/dealer just another tuber.

@tonydennison interesting I have not had those kind of noise issues with my many tubes. Any tube noise issue I have had was a sign of a bad tube and didn’t get better with use  …those GL KT 77 are fantastic tubes…no need to replace those until they wear out.  Get some 6922’s first.

Darn shame…I have not had issues like yours in several years of tube rolling. Only two noisy ones and a few  that just sounded dull.  I guess I am The Lucky One.