View Full Version : 6SN7GT tube - best of vintage and substitutes


seanrr
12-01-2012, 09:22 PM
I have a 300B amp that has a Russian made Tung-Sol 6SN7GT tube as its driver. It sounds very nice, but I can't help thinking that a vintage replacement could make it sound that much better. Since I am new to this tube (all my other tube amps are EL84 based), I have no idea what to look for. So.... I have the following questions for the gurus here:

1) What can one use in place of a 6SN7GT tube? Do regular 6SN7 tubes work? Can one use a 6SN7GTA or 6SN7GTB? What about the European replacement tubes for the 6SN7, like the ECC33?

2) Are there certain 6SN7GT tubes that have particularly good reputations for sonics? For example, I have found that I love the Mullard 12AX7 driver tubes for EL84 based amps. Might there be an equivalent for the 6SN7GT? I would not mind a tad more sparkle in my top end with this amp - so, are there certain driver tubes that might do that better than the Russian one I am now using? Thanks in advance for advice.

gadget73
12-01-2012, 09:59 PM
The GT in this case just means Glass Tubular. It differentiates it from a metal 6SN7 which should also work fine. There is also the 6SN7GTA and 6SN6GTB which will work fine for you. The GTA is a slightly revised 6SN7 to handle higher voltages. The GTB is a GTA with controlled heater warmup, which is really only important in series string circuits.

seanrr
12-01-2012, 10:18 PM
Ooops...I made a mistake, it is actually a 6SL7GT tube. Are those interchangeable with 6SL7GT tube?

battradio
12-01-2012, 10:43 PM
With 6SL7GT and 6SN7GT , they never made a metal tube or st shape in vintage tube . The Made GT's , GTA's and GTB's all interchangeable for audio purposes , some early TV's it made a differance .

I like the sound of the Slyvaina 6SL7GTB myself , i also have very nice sounding early Tungsol .

sony6060
12-01-2012, 10:52 PM
Ooops...I made a mistake, it is actually a 6SL7GT tube. Are those interchangeable with 6SL7GT tube?

6SN7 is not interchangeable with 6SL7. A great 6SL7 are vintage Tung Sol round plate.

jbryant_77
12-01-2012, 11:03 PM
Jan CRC-5961 built like tanks for the space program very nice 6sl7.......
Also the 5692=6sn7
Both are very nice sounding
Jason

kcline
12-02-2012, 06:26 AM
Try some Raytheon JAN 6SU7 GT This type is a 6SL7 selected for matched sides, most 6SU7 found match each other!!

bobrown14
12-02-2012, 06:34 AM
Jan CRC-5961 built like tanks for the space program very nice 6sl7.......
Also the 5692=6sn7
Both are very nice sounding
Jason

6SL7 = 5691

Check out RCA 5691 tripple mica version - 10,000 hr tube same build "type" as the RCA 5692 (6SN7 premium) should be the best of the lot of old stock w/ triple mica and extra support rods.

Cheers,
Bob

cries55
12-02-2012, 04:33 PM
I have a quad of rabbit ear nos 6sn7gt's that test like new. If interested pm me.

Skylab
12-02-2012, 05:24 PM
The Tung-Sol black-glass, round-plate 6SU7GTY is the best 6SL7 I've heard, and I own several dozen different varieties.