Tung Sol 6V6GT

[Gene]

What are your experiences with these tubes?

I have several pairs. 1 pair in a 1957 Gibson GA40. It is a cathode biased class AB amp. Another pair in a Princeton Reverb II.

On the GA40, it is running 48ma @ 300V. Above 12 watts but I've seen cathode biased push pull guys run like this fine for a long time. I read somewhere that these new 6V6GT is rated at 14 watts? I am a bit skeptical about changing the cathode resistor value to play around with bias in an amp such as this. Lowering B+ seems to make more sense. But the GA40 has been up and running for hours now and sounds SO GREAT. I think this is the amp sound for me. It over took my favorite Vox 1965 Cambridge Reverb.

The Princeton Reverb II is a fixed bias amp and the pair is at 31ma @ 382V plate.

I suppose I can change the resistor value in the bias supply but the PRII sounds so good at this point. I don't care about having to replace tubes often.

I like the TungSol 6V6GT out of the rest of the new production tubes. I was just wondering how sturdy these guys were.

 

[slider313]

I've had a pair in my Deluxe Reverb running 22ma@425v for a while without a problem. I treat them as a 14 watt tube. The plates are spot welded which, as far as I know, no NOS 6V6 ever had welded plates. The spacers and getter supports look heavy duty.

 

[Gene]

You have yours roughly at 70% at 14w, then.

I was just concerned the amp blowing up from having it too hot but I think I am cool with these specs for now. I'd rather not sacrifice the sound just to save a few bucks.

 

[Blue Strat]

You have yours roughly at 70% at 14w, then.

I was just concerned the amp blowing up from having it too hot but I think I am cool with these specs for now. I'd rather not sacrifice the sound just to save a few bucks.

You're probably ok, but you could take out your OT if the current is too high and/or you short out a power tube. A replaced cathode resistor will seem trivial at this point.

No NOS 6V6s have welded plates? Haven't checked that one lately...not sure how it's relevant to this discussion even if it is true.

 

[Gene]

I need to really learn the theory on why cathode biased push pull amps run the tubes so hot. My 65 Vox Cambridge Reverb is like that with a pair of EL84s. The cathode resistor on this guy had drifted downwards to like 180 ohms and been running hot for 25 years! I recently changed it back up to spec but still runs hot. Never had an issue though with EL84's blowing up. I still have the original Vox tubes from 1965 that came with it although I am using TADs now.

The cathode resistor in the GA40 is spot on at 200 ohms. I'll pick up the coolest running 6V6 pair and see where it sits.