The BEST system you've ever built !!!!

ARC Ref 2 Preamp
ARC 300w monoblocks
Lector CD Player (2 piece system)
McIntosh MR 78 with Modefferi Upgrade
McIntosh MPI-4
Magneplaner Tympani 1Ds
Valhalla interconnects and speaker cables
Square D 300 amp service... Wiring from main house electric service with 3 separate 20 amp lines ( #10 wire) to audio system
Square D Power Surge protection and line conditioner on each of 3 lines
Linn Sondec with supplied arm and Koetsu Onyx

It's what I built over the years...I cannot part with the 1978 Tympani 1Ds...my wife prefers these to the 20.1s

and most important component..the 16 by 20 Cathedral ceiling room with sprung wood 3/4 inch oak floors.

Mr Stark its a bit late to answer your question. In the sacred "Joe's Tube lore" they are described briefly. Anpther militasry Mullard only midrange and rolled of at the extremes probably only for systems that are harsh and would require taming.
I honestly was shocked by these comments. The only reason I have them is my tube Guru in England said stop messing aroud with the 6922s to me they all sound poorly and sonically their is not anything that really sounds different tube.
I thought my old friend had lost it I could easily hear differences poor lousy crappy and please don't go near me with tube again. He said there is one tube in the whole family worth anything it sound different nd is just bettter . This CV2943 he had none to sell but tubemonger had several sub variants It was not muddied and rolled off. Absolutekluy it fell into the clean deatailed category. Finding a matched quad of NOS these were NIB and still had cihgar rolls around them. I had to get them from Sweden. The price was not my idea of a good time but I saw everything in a 6922 with a good reputation cost the same and even a lot more. These tested stronger than new nominal but was only pretty certain they were True NOS. I saw them I said if that isn't as pristine as I had ever seen then their is no NOS. My 6SN7 guy Len had since eclipsed the perfect period box packing and yes the tubes.
You can find them at Kevin Deal's store in mediocre comdition but if you got the moola it is a must try

Proac Response 2.5 DIY clone. Sonic frontiers line 1. Mark Levinson ML-9. Level 1 Mod (parts connexion) Jolida JD-100. NOS TUBES THROUGHOUT, Amperex, Brimar.

so real