[jimbones]

Hi I am currently using RCA VT231 GG and absolutely love the mids. I also own the Shuguang BT CV181z which is no slouch. I'd like to add to my collection that is still warm in the mids (yet different to the GG). Recommendations are appreciated. Thanks.

[woodsyi]

Some people love the RCA 5692 red base for the legendary warmth and some think it's mush.   I like them in otherwise a bright system. 

[DaveC113]

The 5692 is very good and imo they are all the same... no need to buy only the red base RCA. These are the quietest of the 6SN7s...

Also the Soviet metal-base 6H8C, the best are them have black plates with holes and 1578 markings, then the same without the 1578, then no holes, no holes + grey plates...  I have the no-holes black plate version and they are very good, balanced and clear.

Pretty much all 6SN7s are good... even the cheapest NOS tubes are pretty good.

[dminches]

Here is a good resource.  http://www.dehavillandhifi.com/6sn7_vt.htm

[JackD]

Another good read.

http://www.head-fi.org/t/117677/the-reference-6sn7-thread

[toddc2]

Some people love the RCA 5692 red base for the legendary warmth and some think it's mush.   I like them in otherwise a bright system.

I prefer the RCA 5692 Red Base over the RCA VT-231 although I think they both sound great.

[rbbert]

Remember the 5692 can't be used in all 6SN7 applications (it's a lower voltage tube).

[ssglx]

Sophia Electric 6SN7's made a distinct improvement in my pre-amp. More robust sounding afterwards.

[rotarius]

I have tried many 6sn7 tubes over the years and the ones you might want to get for warmth and sweetness are Ken-rad 6sn7GT. I also like the CBS/Hytron for a more balanced presentation. 

[jimbones]

I was considering the Ken Rad but someone said they "are the opposite of the RCA GG". I found that odd because stuff I read said it had good bass and mids.

[rotarius]

Ken-rads are quite easy to listen to and with nice bass.  Typical of tubes from 40's to early 50's.  RCA GG are perhaps more midrangy with a roll off at both ends.

[paul79]

The 5692 is very good and imo they are all the same... no need to buy only the red base RCA. These are the quietest of the 6SN7s...

Also the Soviet metal-base 6H8C, the best are them have black plates with holes and 1578 markings, then the same without the 1578, then no holes, no holes + grey plates...  I have the no-holes black plate version and they are very good, balanced and clear.

Pretty much all 6SN7s are good... even the cheapest NOS tubes are pretty good.

Absolutely agree here. All 6SN7's are very good. After using these in previous tube gear, then switching to amps that use 12AU7's, I have only found one 12AU7 that is as good as the best 6SN7's, and that is the CBS 7318...

6SN7's don't vary near as widely and wildly as 12AU7's.

[JackD]

The Ken-Rads are more similar to the RCA's than different, just more difficult to find as years of production were less.  The Raytheon VT-231 is another to consider. 

[jimbones]

Well, I made a left turn. I purchased a set of Brimar 6SN7GT Clear Glass. I have read good things about them and understand they are quite hard to find. I hope they sound good!

[jimbones]

I just got the brimars. They are very good. Warm sounding but lighter than the rca gg. Better hi end extension.  Lighter in the bass. I'll need more time listening but I can see why these get such rave reviews

[RPM123]

Remember the 5692 can't be used in all 6SN7 applications (it's a lower voltage tube).

Good point! Here is a quote and a link to an older 6SN7 review:

"I will again caution everyone that various 6SN7 types have different voltage and plate dissipation ratings. The voltage rating refers to voltage across the tube's plate and cathode. To ensure good tube reliability you should probably run a tube at 70% or less of its maximum plate dissipation.

5692 - 275 Volts maximum & maximum 1.75 Watts per section
6SN7GT/WGT -- 300 Volts maximum & maximum 3.5 Watts per section
6SN7GTA/GTB - 450 Volts maximum & maximum 5.0 Watts per section

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."

http://www.dehavillandhifi.com/6sn7_vt.htm

[Syrah]

Mildly off topic, since we're talking NOS here, but I like to keep a pair of Tung Sol 6sn7s on hand - http://www.thetubestore.com/Tubes/6SN7-Tube-Types/Tung-Sol-6SN7GTB

It's a great sounding tube that's very neutral, and a total no-brainer for the price.  I like it as a good base by which I can compare other 6sn7s.

[Justinuthadude]

Kentucky Radio (KenRad) was bought by GE and immediately changed the name. You can tell if they are KenRad or GE by the fact that GEs have side getters and KRs don't. I've bought several Kenrads that were labelled GE, and since KR has a better reputation (and better tubes) than GE, you get them for much cheaper.

[FullRangeMan]

Here is a good resource.  http://www.dehavillandhifi.com/6sn7_vt.htm

Great link:
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.

[J-Pak]

6F8G is a direct 6SN7 substitute and has the same electrical parameters. You can get the adapters on Ebay.

I've replaced most of my high priced 6SN7 with various 6F8G's.