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Top 5 6SN7’s

post #1 of 19
Thread Starter 
What are the 5 or 10 best sounding 6SN7’s?

Manufacturer / Physical Description / Year

I’m trying to find good sounding 6SL7’s for my EAR HP4 by identifying great sounding 6SN7’s and then trying to locate a corresponding 6SL7. I’m hoping the desirable qualities of the tubes will carry across to tubes in the same family.

I just got a pair of Tung-Sol 6SL7’s with round plates and they sound great. I based that purchase on postings indicating the 6SN7 version was good.

It’s kind of a round about way to identify good sounding tubes.

So far my hit list would be:
- Valvo 6SL7 which Hirsch really liked in his EAR HP4 tube rolling thread
- More Tung-Sol 6SL7 round plates.

I like the GE 6SL7 silver plate side getter and have some Mullard 6SL7’s coming.


post #2 of 19
Tom Hankins posted this in response to a similar question in an Eddie Current thread:

what is THE BEST 6sn7 tube to put with this amp?

TungSol round plate
Sylvania VT231
KenRad VT231 (black or clear glass)
National Union (black or grey glass)
Sylvania 6sn7W metal base
RCA grey...
post #3 of 19
Almost all the older 6sl7gt's have round plates. The older sylvania, ken rad, RCA and of course the tung sols I have seen all had round plates. There is a military verion of the 6sl7 called the vt-229. These can be pricey because of the connection with the vt-231's and there is conflicting opinion whether these vt-229's are really any different or better than std 6sl7's. The best 6sl7 I have found is actually called the 6su7gty. These were a military low noise tube made and screened by tung sol that have round plates, black glass, brown bases and are specially matched between the dual triode sections. I use these in my preamp and they are my personal favorites. There is also another military version of the 6su7gty made by tung sol(maybe others?) called the 6188. These are from a later manufacture and these tung sols have clear glass, brown bases and the plates are different, as in, not round plates. The 6188 is still a very good tube but I like the older 6su7gty better. Jamato here on head-fi swears by the sylvania 6sl7gt. I liked the ken rads a little better than the sylvanias I tried.

I have been hunting for the gray glass RCA 6sl7 and the National Union black glass 6sl7 based on how good these sound as 6/12sn7's, unfortunately, without success so far. In my rankings below note I have not actually heard the NU or RCA 6sl7s. I am basing my opinion on the NU and RCA 6/12sn7's I use. Again, the ken rad black glass 6sl7gt's I have are quite good but the 6su7gty is clearly better all round IMO. I like the sylvania but it doesnt match with my system as well as the other two. From my research the black glass tubes are generally held in the highest esteem with tung sol, national union and ken rad being the pecking order. By the way, the 6su7gty is electrically identical to the 6sl7 so there is no issue using these in any amp that uses 6sl7 tubes. The 6su7gty is a drop in replacement. Like I said, I think this tube is better than any of the 6sl7's I tried.

These are the ones I would look for:

1) tung sol 6su7gty
2) ken rad 6sl7gt/ vt-229
3) National Union 6sl7gt
4) RCA gray glass 6sl7gt
5) sylvania 6sl7gt
6) tung sol clear glass 6188/6su7gty
7) RCA clear glass 6sl7gt

My favorite 6sn7 favorites are different than this list.

For gain tubes:
1) ken rad 6sn7 black or clear glass
2 tie) National Union black glass 6sn7/ tung sol round plate black glass 6sn7
3) RCA gray glass 6sn7gt
4) tung sol clear glass 6sn7
5) Raytheon 6sn7/vt-229

For output tubes:
1) sylvania 6sn7gt/ gta
2) dumont labs 6sn7gt/gta
3) RCA 6sn7 clear glass
4) hytron 6sn7gt tall bottles
5) GE 6sn7gta

Hope this helps.
post #4 of 19
Almost forgot. You might like to look at


I was intrigued by the ratings.

[Edit] Apparently the links feature isn't working. You'll need to copy and paste.

Hope it helps.

post #5 of 19
Thread Starter 
Thanks this will give me something to digest.

These are the ones I just got, not labeled but thought to be Tung-Sol 6SL7 round plates.

Unlabeled black glass tubes seem to be a challenge to identify? With more knowledge I think maybe a person could make a reasonable guess based on the visible / top mica structure. I got a black glass tube for 99 cents- the auction was for a closed box listed as 6SL7. Another adventure.

post #6 of 19
I did like how the brimar cv 1988 sounded in my amp .
tungsol is tops though.
post #7 of 19
Mitch, those are Tung Sols for sure. The question is whether they are 6SN7 or 6SL7. If the top mica have no spacers between the grid posts, then you have a 6SL7.
post #8 of 19
Originally Posted by Len
Mitch, those are Tung Sols for sure. The question is whether they are 6SN7 or 6SL7. If the top mica have no spacers between the grid posts, then you have a 6SL7.
Are my eyes good. I can see sl7/ gt printed on the label.
post #9 of 19
Duh! Always overlook the obvious!
post #10 of 19
Thread Starter 
Yeah but:

“If the top mica have no spacers between the grid posts, then you have a 6SL7.”

Is really helpful.

I’ve been buying small lots of 6SL7 tubes on Ebay looking to match up some good ones so the more information on how to identify them the better.

I’m waiting to receive these now with my eye on the Tung-Sol:

post #11 of 19
In the HP4, the only good correlation I got between what I had been hearing with 6SN7's in the ZOTL (at that time), and the 6SL7 was Sylvania. Syl VT-231 and VT-229 were almost identical in their respective amps. There was almost no "house sound" that I could pin down for any other brand I can think of. I've listened to a lot of 6SN7's in the Supra since then, but what I heard rolling 6SL7's in the HP4 has not been very predictive of the sound of most 6SN7's at all.

Look for GE or Amperex 6SL7's with a filament going across the top (same tube, those Amperex 6SL7's were GE production). IIRC those were a nice tube. Some of them had a short enough bottle to fit in HP4 (similar tubes were made with both short and tall bottles).
post #12 of 19
Hey all,

Well, this is my first post here. I stumbled upon this site just today,
whilst doing some research on some tubes I was thinking of buying.

I happen to have a lot of recent experience with both 6SL7's and 6SN7's
and have formed some opinions of the ones I have bought lately.

Naturally these are taken from my listening to my amp and results may
vary for other amps.

First, 6SL7's (and equivalents).

- Best: Sylvania 6SL7WGT Gold (JAN-CHS-6SL7WGT). Brown base, gold print
on tube, chrome top. As one review says, it puts you front and centre -
like the main instruments are just a couple of feet ahead of you -
forward of the speakers. Excellent depth and detail and solo
instruments and classical music just come alive. A real eye opener when
you listen to these. And can be obtained NOS&NIB for a bargain price on
Ebay (as in under US$10!) if you keep an eye out.

- 2nd best: Sylvania 6SL7WGT. Brown Base, green text. Just about
idential to the ones above in sound.
- Equal Second best: Sylvania JAN CHS 6SL7GT/VT-229 (actually says both
on base). Tall bottle, chrome at the bottom, black base, white writing.

3rd best: Raytheon JAN VT-229.

The 2nd and 3rd best ones are similar to the best one: front and
centre, very clear and pronounced. The best one only edges them out by
a tiny amount.

- Mullard ECC35. These are GREAT for really clear voice and have good
detail (a little better than the tubes above), smooth and flowing (good
jazz style tubes) but the clarity, the focus just isnt like the first
three. I can live with these but for certain kinds of music the ones
above just win hands down.

5th: RCA 6SL7 smoked glass. Sounds pretty good all around, but just
doesnt stand out like some of the others.
Ones Im not so impressed with:

- Tungsol Round Plate 6SL7GT. Black base, black glass: too quiet and
innaccurate compared to the ones above.
- Red Base RCA 5691: I have a perrrrrrrfect NOS NIB pair of these and
am not very impressed. They just dont have the depth or detail. I think
its best summed up by one site that says "they lack bandwidth".

For 6SN7's:

First: I prefer 1940's Sylvania 6SN7W (JAN-CHS-6SN7W). Black base,
chrome top. (Pretty expensive).
Note, I havent heard RCA Red Base 5692's yet, nor one particular kind
of Tung Sol Id love to try.

2nd: Standard sylvania chrome top 6SN7 GTs (GTA/GTB etc). There are the
best cheaper alternative, and can be picked up for a bargain.

Third: Tung Sol "Mickey mouse ears" 6SN7GT. Clear glass, grey plates.
Extra round support things at the top. Not bad. Quite clear, but not as
well defined as the others.

Fourth: GE 6SN7GTB, grey plates black base. Sound OK. Nothing to get
too excited about but they do the job.

Anyway, just my thoughts. I have more that I have tried over recent
months, but the text above is a first go at summing up my findings of
some of them.

post #13 of 19
He, this was an old thread.

Anyway, the top 6SN7's

1. Tung-Sol 6SN7GT, black-glass/round-plate.
2. Hytron 6SN7GT, black-base (< ~1955).
3. Sylvania 6SN7GT, "1952-vintage".
4. RCA 6SN7GT, <1949.
5. Sylvania VT-231.

It is difficult to mention one universally good 6SN7GT, since one usually gets the best result by combining different ones for the driver and for the out-put's. Hence, the Sylvania VT-231 is a very good out-put tube in the MPX3, but it needs a very bass-strong driver to excel. It is simply not good enough in it self. The KR and Sylvania VT-231 combination is, as far as I am concerned, still a very strong combination.

The Sylvania 6SN7W (black-base/short bottle) is still collecting yet higher prices, though the worst craziness seems to have slowed down. IMHO, it is not significantly better than an early 6BX7GT to warrant that kind of prices. They are both about the same principle: A larger than life, vigorous, vivid and dynamic sound.

The BRIMAR CV1988 (6SN7GTY) should be in the top 5 as well I think. I am just not sure where, because of its quite different character.
post #14 of 19
Double post I guess...
post #15 of 19
Hey, tripple post. I am sorry.
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