BFC tube rolling

[tsutt]

I was just trying some different tubes in my home built bf vibro champ which i had all jj's and i had just check tube bias on the 6v6 and was fine so i put in an old rca i had from an old Knight signal tracer which has had no use . i checked it on my tube tester bk747b which is calibrated. and it tested good. put it in the champ, smoother and creamier than the jj but after a few minutes the tube was getting really hot. a lot hotter than the jj. So i havent checked the bias which i will do but what do you think the best move is?

Todd

[Structo]

bad tube?

[tsutt]

First of i erred it wasnt this amp i checked bias on it was my spit. im easily confused lol. so i just checked it looks like it's at 15 watts pd. time for a correction.

[Structo]

lol

[tsutt]

I sure can be a dumbass sometimes. all fixed pd is now 11.77. but i notice the rca has no rflective coating at the top of the tube like the jj and now the jj sounds better. little better mids. and i learned what a faulty bypass cap solder joint can do. SO i have a question since im an ignorant green horn. Biasing colder give more or less clean headroom?

[Jana]

Hey now, don't be trying to elbow your way into dumbass--I got that covered.

[tsutt]

Maybe it has to do with being a minnesooootan as im also.

[Jana]

colder will give you more headroom--to a point.

[tsutt]

ok nother stupid question. So i went from462 ohm to 723ohm cathode to drop the current do i have to change the bypass cap also? there seems to be just a little hair, fuzz on a strong pic attack. which wasnt there with the hotter bias.

[tsutt]

Well it seems my rectifier tube sovtec went bad during this it jumped 20 volts output why would this happen it tests good, maybe went of scale on the good side. now running a used sylvania from the 50's voltage back in spec.