odd problem with modded 50 watt Ceriatone OTS

[El_Martin]

Hi!

I'd check solderings around the tube sockets. And -of course- the sockets.

Make sure your inserted sag resistor is well connected/soldered, too.

prolly less than 2c...

Ciao
Martin

[pine]

I think I MAY have found the culprit. My plate voltage was 447 Volts, my bias was at 33, no surprises there, it was always like that, but as per Structo's comment about the tubes being the first suspect, I noticed that V1 felt a little loose in its socket. It is an old Telefunken pulled from a Fisher HiFi, and though other preamp tubes seat firmly, the Telefunken does not.

I looked a little closer and it appears that the actual pins on the tube are slimmer than other tubes'. It's a shame because that tube sounds really good in that position, the vibration must have eased it slowly out of the socket. Anyway, the static went away when I replaced V1 with an inferior sounding tube. When I get time I'll try to retension the socket.

Hopefully that was the problem and it's not one of those intermittent Ghost in the Machine deals where the static temporarily went away by coincidence just as I replaced the tube

[Bob-I]

I think I MAY have found the culprit. My plate voltage was 447 Volts, my bias was at 33, no surprises there, it was always like that, but as per Structo's comment about the tubes being the first suspect, I noticed that V1 felt a little loose in its socket. It is an old Telefunken pulled from a Fisher HiFi, and though other preamp tubes seat firmly, the Telefunken does not.

I looked a little closer and it appears that the actual pins on the tube are slimmer than other tubes'. It's a shame because that tube sounds really good in that position, the vibration must have eased it slowly out of the socket. Anyway, the static went away when I replaced V1 with an inferior sounding tube. When I get time I'll try to retension the socket.

Hopefully that was the problem and it's not one of those intermittent Ghost in the Machine deals where the static temporarily went away by coincidence just as I replaced the tube

Been there, yes that can cause what you described. The retension should work fine, but give it enough time to verify that you've fixed the problem.

[Structo]

Glad you found the culprit.
I have read about some tubes having different sized pins, particularly power tubes.
I hope you can use that Tele tube, as they are supposed to be very good.

[pine]

i think in general 6L6's like it cooler so it doesnt emphisize the farty, crappy, loose bass that 6L6's usually have... which is why KT88's are now my favorite tubes

Are KT88s a drop-in replacement for 6L6GCs? Will they work well in a D-Style circuit?

[dogears]

Food for thought.....

I have a half dozen Telefunkens. I do not prefer them in any way in the preamp slots of any of my Dumble circuits.

Many agree btw. Not just my taste.

[pine]

Want to part with a couple of them?

[JD0x0]

i think in general 6L6's like it cooler so it doesnt emphisize the farty, crappy, loose bass that 6L6's usually have... which is why KT88's are now my favorite tubes

Are KT88s a drop-in replacement for 6L6GCs? Will they work well in a D-Style circuit?

Yes and no. My current build is a KT-88 the amp was designed for 2x6L6 or 2XEL34 im upgrading the power and output tranny and from there they should be able to be dropped right in and biased. It depends on your transformers though.

It's possible to drop right in and bias on a 50 watt tranny but you might not get the correct voltage and the tubes or your tone could suffer.