Solarus tubes

[Valvehead]

Im working on a 69 Solarus . This one is wired for the 7199 / EL34 combo. 60 watts ?

I do have a 6an8 and 6550 pair here , but i dont want to re-wire that socket....one reason is neither scem matches the amp , which Im told is kinda normall for old Sunns ?

My question is , at 530vdc plates (with el34s in there ) are modern el34s ok with that kind of voltage? I have several brands here . Would it be safer to go to 6550 , even though i think they draw more current ??

Has anyone swapped these ? Tone difference ?

[Leo_Gnardo]

FWIW there are pin-scrambler adapters that let you run a 6GH8 or 6U8 in a 7199 socket. Expect about $20. Antique/Tubesandmore is where I got mine. I get best results generally from 6GH8A, and find I have to select for lowest noise.

As long as you alter your bias supply so it can provide voltage needed by 6550 you can use them. Or KT88 for a real treat.

[Valvehead]

ok thanks----looks like i would have to dremel off the tube shield base , to use that adapter ?

[Leo_Gnardo]

ok thanks----looks like i would have to dremel off the tube shield base , to use that adapter ?

I s'pose, thems the choices. Maybe just as well to replace the socket entirely. Whichever tube you use, it's an inverter/drive section for your power tubes. Having a cover over the tube won't make much difference as far as noise/hum. OTOH I have run across plenty of humming 7199's. 6GH8A, not so much.

About the other choice, 6AN8, they were commonly used in a similar way to 7199, an inverter/drive system. I noticed they were also getting scarce about 10 years ago.

[Enzo]

They used the 6AN8 with the KT88 amps, and the 7199 with the EL34 amps.

[Valvehead]

Yep, I have a 7199 on the way. If its noisy i will go with the adapter and a 6an8 / kt88