6SN7 vs 6SN7GTB

[MarkC]

Are these two tubes basically drop in replacements for each other?
I know the GTB has a slow warmup characteristic but if I had a
schematic which called for the GTB tube, could a regular 6SN7 be used without mods to the circuit? Thanks in advance for the info. Mark

[erichayes]

Hi All,

For the most part, Mark, the 6SN7 will work in audio applications where the plate voltage is less than 300 VDC. The GTA and GTB versions were developed when it was found that the 6SN7 made a great vertical oscillator in the early TV days, but needed to be beefed up to handle the increased stress put on the tube. A lot of 6SN7 afficionados think the old WWII vintage Sylvania and Tung Sol versions are the paradigm. I personally think the Electro Harmonix 6SN7EH gives them a pretty good run for their money. Sovtek and Sino 6SN7s make wonderful omnidirectional microphones.

[MarkC]

Hi All,

For the most part, Mark, the 6SN7 will work in audio applications where the plate voltage is less than 300 VDC. The GTA and GTB versions were developed when it was found that the 6SN7 made a great vertical oscillator in the early TV days, but needed to be beefed up to handle the increased stress put on the tube. A lot of 6SN7 afficionados think the old WWII vintage Sylvania and Tung Sol versions are the paradigm. I personally think the Electro Harmonix 6SN7EH gives them a pretty good run for their money. Sovtek and Sino 6SN7s make wonderful omnidirectional microphones.

Thanks Eric...The EH 6SN7 is what I have...
after researching several different designs,
I've decided to go with one that called for a 6SN7GTB so, I should be good...Thanks for the info...Mark

[dhuebert]

Sovtek and Sino 6SN7s make wonderful omnidirectional microphones.

I just bought a couple of Sovtek 6SL7 to use as phase invertors in my guitar amps (don't ask why). Have you found these to be very microphonic as well? The one bass amp I built this way seems OK so far.

Don

[erichayes]

Hi All,

Don, I bought a couple of Sovtek 6SL7s about seven years ago and they weren't any more microphonic than the NOS RCA and Sylvania samples I had. The only thing remarkable about them was that they were rather dark sounding. I have a hunch that they were the Russian "equivalent" of the 6SL7, as they bore little physical resemblance to US manufactured 6SL7s.