The Reference 6SN7 Thread

[Jon L]

I would like some feedback on the difference in sound between 1940's era RCA 6SN7-VT231 and Sylvania 6SN7-VT231 if at all possible. Right now I'll using Sylvania 6SN7GTB in the late 50's early 60's era.

Are you talking about RCA black glass or grey glass? I prefer the Sylv VT231 to the RCA black glass, but RCA grey just sounds more "special" (colored, colorful, whatever).

Back in the day, I swapped with somebody some of my Tung Sol VT231 roundplates for his Syl VT231, a poor decision investment-wise, but I do prefer the sound of Syl to Tung Sol.

 

[tdadawa]

I always wondered if tube microphonics is the same thing as a system sounding toobey and if tube dampers, like o rings, would solve the problem.

 

[tdadawa]

Are you talking about RCA black glass or grey glass? I prefer the Sylv VT231 to the RCA black glass, but RCA grey just sounds more "special" (colored, colorful, whatever).

Back in the day, I swapped with somebody some of my Tung Sol VT231 roundplates for his Syl VT231, a poor decision investment-wise, but I do prefer the sound of Syl to Tung Sol.

Good to know Jon, I guess black or grey glass, I'm trying to figure out what I want to buy to sound better than my Sylvania Baldwin 6SN7GTB.

 

[steve468]

I believe H4E is 1944 Jul-Aug as from 1947, RCA started using all numbers for dating. Dont mind me, have you checked for microphonic? I asked because I have multiple pairs from 1942-1944 and they dont sound harsh on 2 amps I have tried so far. One thing I have observed is this RCA smoked glass is slightly microphonic if placed in certain socket position but not in another. They are a bit sensitive to micro-vibration when current passes through. Just a thought.

I’m aware I’m in the minority in that assessment. It could also be my inability to properly describe what I’m hearing. But cymbals go shtshhh instead of ting.

 

[Ranger Ron]

Good to know Jon, I guess black or grey glass, I'm trying to figure out what I want to buy to sound better than my Sylvania Baldwin 6SN7GTB.

You could try Westinghouse GTB’s, they are found fairly cheap and sound very good. Raytheon GTB sound decent too and again reasonably priced.
I’ve also had good luck buying Australian made tubes from Australian fleabay sellers. Great sounding tubes again at real world prices.

 

[Renexx]

You could try Westinghouse GTB’s, they are found fairly cheap and sound very good. Raytheon GTB sound decent too and again reasonably priced.
I’ve also had good luck buying Australian made tubes from Australian fleabay sellers. Great sounding tubes again at real world prices.

Did you grab a pair of a 40s AWV vt-231 smooth plates or a nice pair 50s pair with staggered plates ?

Westinghouse and Raytheon GTB would be only a side grade.

Good to know Jon, I guess black or grey glass, I'm trying to figure out what I want to buy to sound better than my Sylvania Baldwin 6SN7GTB.

Sylvania GTB is a great performing tube for a fair price.

Depends to your budget and your sonical preferences. For sure RCA vt-231 will be a fine upgrade.
RCA never made a black glass 6sn7.

 

[Ranger Ron]

Did you grab a pair of a 40s MWT vt-231 smooth plates or a nice pair 50s pair with staggered plates ?

Westinghouse and Raytheon GTB would be only a side grade.


Sylvania GTB is a great performing tube for a fair price.

Depends to your budget and your sonical preferences. For sure RCA vt-231 will be a fine upgrade.
RCA never made a black glass 6sn7.

AWV Radiotron
The pair with the support rods are very special.

 

[Renexx]

AWV Radiotron
The pair with the support rods are very special.

Australian tubes are lovely and quite overlooked by the community.
Ah the support rods are used in the 40s version also. Your tubes are labeled as GTA. Never saw that before.

The Staggered plates version sounds nicely warm. Earlier version is more balanced.

 

[Ranger Ron]

Australian tubes are lovely and quite overlooked by the community.
Ah the support rods are used in the 40s version also. Your tubes are labeled as GTA. Never saw that before.

The Staggered plates version sounds nicely warm. Earlier version is more balanced.

I agree. I bought the three GTAs for a pair of AtmaSphere M60’s, they run one of the 6SN7’s at

Australian tubes are lovely and quite overlooked by the community.
Ah the support rods are used in the 40s version also. Your tubes are labeled as GTA. Never saw that before.

The Staggered plates version sounds nicely warm. Earlier version is more balanced.

Australian tubes are lovely and quite overlooked by the community.
Ah the support rods are used in the 40s version also. Your tubes are labeled as GTA. Never saw that before.

The Staggered plates version sounds nicely warm. Earlier version is more balanced.

Those bottom two tubes are from the 40’s. They are GT’s. I bought the three GTAs for a pair of AtmaSphere M60 amps. They run one of the 6SN7’s harder than GTs can handle.
I agree, lovely tubes

 

[Renexx]

I agree. I bought the three GTAs for a pair of AtmaSphere M60’s, they run one of the 6SN7’s at


Those bottom two tubes are from the 40’s. They are GT’s. I bought the three GTAs for a pair of AtmaSphere M60 amps. They run one of the 6SN7’s harder than GTs can handle.
I agree, lovely tubes

Oh my pair has support rods also

The early vt-231 version has round mica and unique smooth plates. Unobtanium treasures.

 

[Ranger Ron]

Oh my pair has support rods also


The early vt-231 version has round mica and unique smooth plates. Unobtanium treasures.

I want those! Beautiful. Thank you for sharing. Do they sound any better than the two in your first photo?

 

[Renexx]

I want those! Beautiful. Thank you for sharing. Do they sound any better than the two in your first photo?

Well I didn't listen to the vt-231 very long. They are so pristine in NIB condition. I'm scared to actually enjoy them They rival the vt-231 American variants.

The staggered plates pair sounds wonderful warm with less resolution than smooth plates. These are quite balanced. I should give them a listen again.

 

[TLO]

Oh my pair has support rods also


The early vt-231 version has round mica and unique smooth plates. Unobtanium treasures.

The one with supporting rods remind me of Raytheon VT-231 flat plate.

 

[Renexx]

The one with supporting rods remind me of Raytheon VT-231 flat plate.

Sonically it's sounds warmer than a Raytheon vt231.
I think Mullard had a factory in Australia. There is a Mullard labelled 6sn7gta version that was build in Australia. Sadly I can't find a picture of those tubes.

 

[TLO]

Sonically it's sounds warmer than a Raytheon vt231.
I think Mullard had a factory in Australia. There is a Mullard labelled 6sn7gta version that was build in Australia. Sadly I can't find a picture of those tubes.

Yes, I would think so when you commented this sounds really good and warm as I always find Raytheon sounds too thin for my taste. Thanks for sharing.