The 6SN7 Identification Guide

[sennfan83261]

I can't believe that 11 year old post is still one of the de-facto definitive guides to 6F8G comparisons. But yeah they are still spot on. It's funny, doesnt matter what variant/type of tube it is, Ken-Rads always seem to evoke a mixed reaction, and GEs (genuine GE made not rebranded) almost always suck the most.

Maybe time for a 6F8G/VT-99/6C8G/VT-163 lovers thread?

 

[Ranger Ron]

I can't believe that 11 year old post is still one of the de-facto definitive guides to 6F8G comparisons. But yeah they are still spot on. It's funny, doesnt matter what variant/type of tube it is, Ken-Rads always seem to evoke a mixed reaction, and GEs (genuine GE made not rebranded) almost always suck the most.

Indeed. I have 6f8g labeled KenRads that have T plates, the staggered flat plate, and round plates.

 

[sennfan83261]

Indeed. I have 6f8g labeled KenRads that have T plates, the staggered flat plate, and round plates.

Yeah, I've seen the same variation with my 6F8G Ken Rads, probably some of them rebrands. Kind of like the clear glass 6C8G Tung-Sol shown below. It looks exactly like my RCA two-mica meatball logo 6C8G expect that the round plates on the Tung-Sol feature wider separation than the round plates of the RCA. I have another clear glass 6C8G Tung-Sol with support rods between the two mica. I never seen a clear glass Tung-Sol for a 6C8G, as I thought all of the Tung-Sol 6F8G/6C8G's had black glass. I think that my Tung-Sols are rebrands, but from where? I took a flyer on them because they were cheap and I'm pleasantly surprised that I like them more than my Ken-Rads and National Unions 6C8G's [clearer sound, better technicalities (e.g. layering), widest soundstage, kind of more forward sounding than the others]. The Tung-Sols certainly sound way different to the more closed-in, dry sounding RCA 6C8G's on my CTH. I have a black glass Tung-Sol 6C8G on the way and I hope it isn't microphonic. Damn, I thought I left tube-rolling behind when I ventured into the world of planars, but somehow it always draws me back, lol.

 

[sennfan83261]

Below is a visual aid to what I talked about earlier (6C8G's L to R: RCA, Tung-Sol, National Union). The other Tung-Sol 6C8G not pictured (because it is in my CTH while I'm listening to it right now ) bears a closer resemblance to the pictured National Union 6C8G than the RCA and Tung-Sol below, but yet they sound dissimilar to each other. As far as I know, the Tung-Sol's could have been silk-screened on the base. The Tung-Sol not pictured has a date code that I don't jive with: 322613 (1961? Unlikely... 1946, 13th week?); the one picture is without a date code on the base. Whatever, they were cheap and they sound great!

Circling the wagons back to the 6SN7's, I remember buying a Jackson 6SN7GT with mouse-ears that looked like a clone of my Tung-Sol 6SN7GT mouse-ears. I thought it was a rebrand and it was a few bucks, so why not? The Jackson 6SN7GT was probably towards its end of its life because it sounded like ass compared to the branded Tung-Sol mouse-ears.

 

[JKDJedi]

Below is a visual aid to what I talked about earlier (6C8G's L to R: RCA, Tung-Sol, National Union). The other Tung-Sol 6C8G not pictured (because it is in my CTH while I'm listening to it right now ) bears a closer resemblance to the pictured National Union 6C8G than the RCA and Tung-Sol below, but yet they sound dissimilar to each other. As far as I know, the Tung-Sol's could have been silk-screened on the base. The Tung-Sol not pictured has a date code that I don't jive with: 322613 (1961? 1946, 13th week?); the one picture is without a date code on the base. Whatever, they were cheap and they sound great!

Circling the wagons back to the 6SN7's, I remember buying a Jackson 6SN7GT with mouse-ears that looked like a clone of my Tung-Sol 6SN7GT mouse-ears. I thought it was a rebrand and it was a few bucks, so why not? The Jackson 6SN7GT was probably towards its end of its life because it sounded like ass compared to the branded Tung-Sol mouse-ears.

46 more like it... heck maybe even 36! For sure not a 61, Have an RCA 6F8G (flat plates) I haven't rolled yet, maybe this weekend.

 

[attmci]

Below is a visual aid to what I talked about earlier (6C8G's L to R: RCA, Tung-Sol, National Union). The other Tung-Sol 6C8G not pictured (because it is in my CTH while I'm listening to it right now ) bears a closer resemblance to the pictured National Union 6C8G than the RCA and Tung-Sol below, but yet they sound dissimilar to each other. As far as I know, the Tung-Sol's could have been silk-screened on the base. The Tung-Sol not pictured has a date code that I don't jive with: 322613 (1961? Unlikely... 1946, 13th week?); the one picture is without a date code on the base. Whatever, they were cheap and they sound great!

Circling the wagons back to the 6SN7's, I remember buying a Jackson 6SN7GT with mouse-ears that looked like a clone of my Tung-Sol 6SN7GT mouse-ears. I thought it was a rebrand and it was a few bucks, so why not? The Jackson 6SN7GT was probably towards its end of its life because it sounded like ass compared to the branded Tung-Sol mouse-ears.

All my TS 6C8G has black glass.

 

[sennfan83261]

All my TS 6C8G has black glass.

Which is why I said that it may be a rebrand in my earlier post, as I'm accustomed to seeing TS 6C8G RP's with black glass. So, I was and still remain a bit skeptical. IIRC, Tung-Sol and RCA made tubes for each other in the 1930's and/or 1940's. However, there are marked differences between clear glass "TS" shown in my post and the RCA 6C8G (meatball logo, two circular micas) pictured alongside it: larger gap between the RP's and different sized rivet holes. More important than the eye test, they pass the ear test, as the TS clear-glass sounds completely different to the RCA and better (to me) than my Ken-Rads, National Unions, and RCA's. My other clear glass Tung-Sol has 322613 stamped in its base, 322 indicating that Tung-Sol manufactured it. Still, who knows if the EIA code goes back to the late '30s or '40s? Or if the code was fraudulently silk-screened on the base? If someone tried to pull one over me for $15-20, they should have picked a crappier sounding tube. I guess what remains is the comparing the clear glass TS to the black glass TS 6C8G that's on my way.

 

[bcowen]

Damn, I thought I left tube-rolling behind....

There is no cure. Trust me -- I've read the internet from start to finish looking for one.

 

[JKDJedi]

Which is why I said that it may be a rebrand in my earlier post, as I'm accustomed to seeing TS 6C8G RP's with black glass. So, I was and still remain a bit skeptical. IIRC, Tung-Sol and RCA made tubes for each other in the 1930's and/or 1940's. However, there are marked differences between clear glass "TS" shown in my post and the RCA 6C8G (meatball logo, two circular micas) pictured alongside it: larger gap between the RP's and different sized rivet holes. More important than the eye test, they pass the ear test, as the TS clear-glass sounds completely different to the RCA and better (to me) than my Ken-Rads, National Unions, and RCA's. My other clear glass Tung-Sol has 322613 stamped in its base, 322 indicating that Tung-Sol manufactured it. Still, who knows if the EIA code goes back to the late '30s or '40s? Or if the code was fraudulently silk-screened on the base? If someone tried to pull one over me for $15-20, they should have picked a crappier sounding tube. I guess what remains is the comparing the clear glass TS to the black glass TS 6C8G that's on my way.

Please. Chime in with that comparison.

 

[sennfan83261]

Please. Chime in with that comparison.

Sure thing! So I received my TS black-glass round-plate (BGRP) 6C8G the other day, and what was immediately apparent was the large soundstage and clarity provided by it to the CTH (most preamp TS tubes that I've tried seemed to be more on the clearer side of things rather than reverby). Other TS pre-amp tubes that I've tried include the 6SN7GT mouse-ears (black plates and gray plates) and the 6SN7GTB in my Darkvoice. With the clear-glass (CG) branded TS 6C8G's, the clarity was there, but a touch less than the TS BGRP, and the soundstage was just as large. The TS CGRP's were also slightly less forward than the TS BGRP and maybe a touch warmer (really too close to tell since I only have one CTH and can't immediately switch back and forth to compare). Both the TS BGRP and the TS CGRP 6C8G's exhibit nice layering capabilities due to their large soundstage and clarity and are both head and shoulders over the RCA meatball logo, round-micas 6C8G pictured below, the latter of which is rather dry sounding and lacking technicalities. Since my three TS 6C8G's cost between $14-25 a piece, I'm not going to be too chuffed if the TS CGRP's are a rebrand since they seem to be produced more towards to Tung-Sol's specifications, at least to my ears.

BTW, how is the RCA gray glass flat-plate 6F8G? Did you roll them into your DV336? My DV336 that I left behind in my city apartment is driven by an RCA gray glass (RP or FP? I forgot) 6F8G too.

6C8G's pictured below (L to R): RCA (S4E), TS CGRP, TS BGRP, TS CGRP (322613), National Union

 

[JKDJedi]

Sure thing! So I received my TS black-glass round-plate (BGRP) 6C8G the other day, and what was immediately apparent was the the large soundstage and the clarity provided by it to the CTH (most preamp TS tubes that I've tried seemed to be more on the clearer side of things rather than reverby). Other TS pre-amp tubes that I've tried include the 6SN7GT mouse-ears (black plates and gray plates) and the 6SN7GTB in my Darkvoice. With the clear-glass (CG) branded TS 6C8G's, the clarity was there, but a touch less than the TS BGRP, and the soundstage was just as large. The TS CGRP's were also slightly less forward than the TS BGRP and maybe a touch warmer (really too close to tell since I only have one CTH and can't immediately switch back and forth to compare). Both the TS BGRP and the TS CGRP 6C8G's exhibit nice layering capabilities due to their large soundstage and clarity and are both head and shoulders over the RCA meatball logo, round-micas 6C8G pictured below, the latter of which is rather dry sounding and lacking technicalities. Since my three TS 6C8G's cost between $14-25 a piece, I'm not going to be too chuffed if the TS CGRP's are a rebrand since they seem to be produced more towards to Tung-Sol's specifications, at least to my ears.

BTW, how is the RCA gray glass flat-plate 6F8G? Did you roll them into your DV336? My DV336 that I left behind in my city apartment is driven by an RCA gray glass (RP or FP? I forgot) 6F8G too.

6C8G's pictured below (L to R): RCA (S4E), TS CGRP, TS BGRP, TS CGRP (322613), National Union

Loving it! An all day tube. Rolls well with the 7236. Nice width. Would love to have one of them Tung Sol. Nice collection there.

 

[highstream]

Anyone seen this Psvane tube version before? Recognize what the name on top is?

 

[Slade01]

Anyone seen this Psvane tube version before? Recognize what the name on top is?

I believe this may have been stock tubes for the OldChen tube amps. example: (https://www.hifi-amplifiers.com/en/...eamplifier-bass-adjustment-preamp-p-5541.html)

 

[sennfan83261]

I believe this may have been stock tubes for the OldChen tube amps. example: (https://www.hifi-amplifiers.com/en/...eamplifier-bass-adjustment-preamp-p-5541.html)

From the description of the amp: "1. With the direct amplification function of ordinary bile preamp, and adding a moderate high and low tone adjustment..."

Oh, Chingrish...

Anyways, those tubes look like tubes even a grandma would love, who could probably ID 6SN7's better than we can, lol.

 

[highstream]

Thanks. I saw them on eBay, but the gd-parts site link for the tube goes to AliExpress, where it says they have a 1000 pairs.