For audio purposes, not much. The GTB just implies appropriateness for certain other uses (typically durability is the relevant factor, afaik)
Depends on who made it and when. Assume basic interchangeability, but there are differences in distortion and gain from manufacturer to manufacturer.
The 6SN7GTB is a special with a higher 450 volt plate voltage rating! You can use these for drivers where you need lots of shwing.
So in a pre amp other then manufacture sonic difference they are the same except for plate voltage. One could use a GTB in place of a 6sn7 but probley should not go the other way if the unit was designed for the GTB, is the correct?
You are correct sir! If you get a copy of Morgan Jone's book "Valve Amplifiers", 3rd edition, you will see extensive analysis and comments including distortion measurements on 6SN7's and the 6J5 (same size bottle but only half as filling).
I only found this tidbit of knowledge out recently during a visit to my establishment by the author Mr. Jones in the flesh. He was perusing through my audio valves inventory and saw some NIB 6SN7GTB Hit-Rays. He specifically suggested that I not waste them wherever I need merely a 6SN7 and explained why. I had previously assumed (mistakenly) that ALL 6SN7's had the 450 volt plate rating.
I only found this tidbit of knowledge out recently during a visit to my establishment by the author Mr. Jones in the flesh. He was perusing through my audio valves inventory and saw some NIB 6SN7GTB Hit-Rays. He specifically suggested that I not waste them wherever I need merely a 6SN7 and explained why. I had previously assumed (mistakenly) that ALL 6SN7's had the 450 volt plate rating.
The only difference between GT, GTA and GTB is controlled heater characteristic (for series-connected heaters in ratios and televisions). It has absolutely nothing to do with the sound.
Tim
Tim
I have the book on order so should have it by the end of the week. This should take care of my winter reading for sometime.
6SN7 & GT = 300V, GTA & GTB = 450V
According to the datasheets at Frank's Electron tube Pages for the 6SN7, 6SN7GT, and 6SN7GTA and GTB, the 6SN7 and GT have a max plate voltage of 300V, while the GTA and GTB have a max of 450V. The GTB differs from the GTA in that the former has a controlled heater warm-up time.
According to the datasheets at Frank's Electron tube Pages for the 6SN7, 6SN7GT, and 6SN7GTA and GTB, the 6SN7 and GT have a max plate voltage of 300V, while the GTA and GTB have a max of 450V. The GTB differs from the GTA in that the former has a controlled heater warm-up time.
Ontario Audiophiles living in the GTA (Greater Toronto Area) might like to think that the 6SN7GTA was a special made just for them! 😀
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