[Koolind]

Having listened to two RCA 6as7g's; one grey-plate with top-getter and one black-plate with bottom-getter i dont hear that much of a difference i must admit. At least the difference is very subtle i think ?

 

[Skylab]

Yes, that has always been my opinion. The difference between ANY of the RCA 6AS7G's is very, very subtle. What I call the shiny black plate Tung-Sol 6AS7G sounds a little more distinct, IMO. And the GEC UK made 6AS7G sound quite different, but they are physically very different as well. And then of course the 5998 sounds even more different, as it is, in fact, a different tube.

 

[pataburd]

Quote:

Originally Posted by Koolind /img/forum/go_quote.gif Having listened to two RCA 6as7g's; one grey-plate with top-getter and one black-plate with bottom-getter i dont hear that much of a difference i must admit. At least the difference is very subtle i think ?

FWIW, I found the grey plates airier, more expansive, more midrange rich and softer/more diffuse in the bass compared to the black plates. The latter, to me, sounded harder with the 336i. I thought the RCA 6AS7G black plates suited the DV337 better. With the 336i, I liked the Sylvania 6AS7, Svetlana 6H13C and Mullard 6080 much better than the RCA 6AS7G black plates, albeit, I never heard the 5998 with the 336i, though. : )

 

[shiaokun]

this week...interrupting the GE run for:

RCA JAN 6AS7G 69-39 (red text) a grey-plate (thanks to all for identifying it!)
RCA JAN CRC-6SN7-GT (used previously)

just notice there are text etched on the 6SN7 glass:
SPERRY No.
718115

i am guessing these are some sort of supply no. since this is a JAN tube?

 

[Skylab]

Sperry was a computer maker (among other things). Apparently they had that tube in stock at some point.

 

[shiaokun]

thanks for the info. skylab.

i agree with pataburd re: the gray-plate sounds "expansive"...listening to a piano solo CD and it sounds like i am in a music hall.

 

[glitch39]

Quote:

Originally Posted by shiaokun /img/forum/go_quote.gif i agree with pataburd re: the gray-plate sounds "expansive"...listening to a piano solo CD and it sounds like i am in a music hall.

Depends ont the circuit. for this DV336, I think the gray plate is better. for the DV337, I'd go with the black plate.

YMMV, of course. the difference may be subtle, huge or even zero. it all depends on how good your cans, DAC and transport are in discerning those differences.

 

[shiaokun]

received a new package with more tubes! yeah!

since the RCA gray-plate RCA JAN 6AS7G was just put in last week, i am pairing it with a RCA 6SN7 GTB.

there's no date code, so once again go to the pcitures and see for yourselves.

i'd appreciate if someone can tell me more about it.

"LQ"?

 

[glitch39]

that's an RCA 6SN7GT(B) with staggered flat plates and bottome getter (I am guessing D or square-shaped). It's a nice tube for the 336. nice extended highs from this tube.

 

[pataburd]

RCA made a later version, I think, of the 6SN7GTB with orange-ish print. I like the ones with the silverish print better. The RCA 6SN7GT gray glass was one of my favorite tubes for the Darkvoice 336.

 

[Skylab]

That's a pretty typical (relatively) early RCA GTB with flat black "ladder" plates. The GTB was introduced in 1950 I believe. In general, GTB's are considered to be not as good sounding as GTA's, or the older GT's, and of course the GTA and GTB are slightly different from a GT, which can handle less plate current than a GTA or GTB (the latter of which can be used completely interchangeably).

RCA did indeed make several later versions of the 6SN7GTB - that is a very early GTB.

 

[shiaokun]

wow! thanks to all for the info.

just took two more shots for the inner works...

 

[Oskari]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif The GTB was introduced in 1950 I believe.

GT 1941, GTA 1950, GTB 1954.

 

[Oskari]

Quote:

Originally Posted by shiaokun /img/forum/go_quote.gif "LQ"?

Jan 60 shipment date. See RCA DATE CODES.pdf.

 

[shiaokun]

thanks! Oskari.

now here are some off-topic pics.

these are the boxes the latest batch of 6SN7 tubes came in with. i am not so sure that they are the "correct" packaging though. for one, i bought them as used tubes, not NOS. plus, 6SN7 was written on tapes attached to the sides and not printed on the boxes. anyway, some nice vintage tube boxes.