Using the general audio application of 250 plate volts, a bias of 8 volts results in 9ma of current and a plate dissipation of 2.25 Watts, we find:

5692 - runs 43 % over maximum rating – It isn’t a 10,000 hour tube when you run it this HOT!
6SN7GT - runs 64% of maximum – coasting and liking it
6SN7GTA/GTB - runs 45% of maximum – Hardly turned on, may outlast you.

When in doubt check with the manufacturer of your equipment. If they provide a schematic with component values and voltages, it's easy to use Ohm’s law to calculate the current and dissipation. There really is no reason for manufacturers not to provide this information.

Here are the rankings. If you have anything to add, email me and I will add it to the list.

Tung-Sol Round Plates, VT-231 or 6SN7 - Clean, fast, the best in everything, wide bandwidth, great resolution. If you can’t find the Music, it’s not the tube’s fault.

RCA VT-231, black plates, rich harmonic structure, beautiful timbre and voicing, wide soundstage

6SN7W or WGT Sylvania black plates – Tied for second and came in first if your system sounds a little laid back, especially some single ended amplifiers – Excellent low level detail resolution, very immediate sounding with a lot of Slam. There are three types of these tubes, two large bottle types, one has a metal ring and one smaller bottle with  smaller plate structure. The smaller one has better low level detail and the larger ones have more slam.

Raytheon VT-231, black flat plates - like the Tungsol a little sweeter, nice balance of detail and timbre

Ken-Rad VT-231, flat black plates - Great Bass, drive, sweet midrange, good bandwidth althought micrphonic tendencies on preamps.

Sylvania VT-231, black plates, wide bandwidth, well balanced, excellent sound stage and air.

 

Sylvania 1952 JAN-CHS-6SN7GT bottom getter: construction identical to the earlier VT231 but sonics are not, exceeds the VT231 in every respect, real bad boys excell in every area, big tight bass, warm detailed mids, extended smooth highs, very open

National Union VT-231 - good drive and great midrange, softer bass and a touch euphonic

Tung-Sol 6SN7WGT, Black Plate, brown base – Sounds similar to the Tung-Sol VT-231, not as clean

Tung-Sol 6SN7WGT, Black Plate, brown base – Very good bandwidth, bass, detail and soundstage,

CBS/HYTRON 6SN7GT, Black Plate, quiet and musical, the best of the non-military tubes

Ken-Rad6SN7GT, black base, bass a little tubby, but clean with great ambiance and air

Sylvania Green Label 6SN7GT, first top getter on the list, non-fatiguing, smooth, with good detail resolution and bandwidth, plus its easy to find and afford.

RCA Black Plate 6SN7GT, still a side getter, rich harmonic structure and maybe a little too sweet.

Sylvania Green Label 6SN7GTB, rich harmonic structure, good midrange, decent soundstage

General Electric Black Plate 6SN7GTA, the great driver tube? Fast, wide bandwidth, smooth sound at the expense of the of low level detail. Along with the Sylvania 6SN7GTB, a great “fourth” tube in Atma-Sphere amps.

Sylvania Green Label 6SN7WGT, Top Getter, “silver top” , very clean with great detail resolution and speed. Bass can be a little tubby and midrange a little congested.

6SN7WGTA, Sylvania black base green label, clean and fast with great drive, good bass

CBS-Hytron 5692, fast, good dynamics, lot of air and great timbre

RCA Red Base 5692, very warm sweet sound, great on voices and jazz

RCA 6SN7GTB, rich midrange, warm sound, likes being combined with other 6SN7 types, likes the Atma-Spheres

G.E 6SN7GTB, Gray plates, work horse, lacks refinement, a good tube

One thing became clear based on customer feedback, combining 6SN7 types seems to work better than using all 6SN7s of the same type. With so many preamps and amps using this tube, you can end up with Six 6SN7s per channel. It appears combining tubes like the VT-231s as voltage amplifiers and 6SN7Ws or 6SNGTA/GTBs as driver tubes you gain the strengths of all. Using one type seems to accentuate the tube’s weaknesses.