Using 6L6 type power tubes

[crunchee]

I LOVE old Fender Blackface tube amps (mid '60's models), but they often call for 6L6GC type power tubes/valves. NOS JAN (Joint Army-Navy, i.e. military grade) USA-made Sylvania/Philips 6L6GB/5881s are cheaper, and I've heard of people using them with no big problems in amps that call for 6L6GCs. These articles seems to bear this out, more or less:

http://thetubestore.com/6l6templeton.html

Kinda a old article ($60.00 for a Mullard GZ34/5AR4?!? I don't think so, not anymore! ) but still kinda useful for info:

http://acruhl.freeshell.org/mga/main/tubes.html

But then I see something like THIS:

http://www.vacuumtubes.com/6l6.html

No affiliation, I'm definitely not endorsing this guy, but you can see what I mean, and this shows my question as clearly as anything else could. NOS US made 6L6GCs are freakin' expensive in comparison to the NOS US made 6L6GB/5881 types. Yeah, I could settle for Eastern Euro, Russian, or Chinese 6L6GCs, but why should I HAVE to? Any recommendations or tales of experience? TIA!

[ArnieZ]

The SED winged c 6l6 GC is an excellent sounding tube and can be bought for about $85 a matched pair. If you change tube type you will have to be careful about bias and plate voltage. If you're comfortable with that you can try the other tubes and see how they respond. They may have shorter life.

ArnieZ

[crunchee]

Cool info, and useful to be sure, but it still has me wondering, and back to the original question: Can I use NOS JAN Sylvania/Philips 6L6GBs/5881s, in place of 6L6GCs in a old Blackface/Silverface Fender amp? The guy with the store says no, and that I should buy his more expensive 6L6GCs instead. The Fender amps I'm planning to use them on don't have a plate voltage higher than 470V according to their schematics, they're often a bit lower depending on the model, usually in the 450V range. So, what say ye?

Also a secondary question: How can I find out how much voltage is coming out of a power supply? Power supply for a house is supposed to be 110V, or 117V, depending on who you listen to: but I've heard that it can be as high as 125V, and the variance will sock more (or less) power to your power tubes accordingly.

[murkat]

Ask Adam, the all knowing fender guy.

http://www.tungstenamp.com/

great guy for info on what you may need.

Make a great amp as well.

Love my 12" Mosaic. (9 watts of pure hell)

[Brewmaster]

Cool info, and useful to be sure, but it still has me wondering, and back to the original question: Can I use NOS JAN Sylvania/Philips 6L6GBs/5881s, in place of 6L6GCs in a old Blackface/Silverface Fender amp? The guy with the store says no, and that I should buy his more expensive 6L6GCs instead. The Fender amps I'm planning to use them on don't have a plate voltage higher than 470V according to their schematics, they're often a bit lower depending on the model, usually in the 450V range. So, what say ye?

Also a secondary question: How can I find out how much voltage is coming out of a power supply? Power supply for a house is supposed to be 110V, or 117V, depending on who you listen to: but I've heard that it can be as high as 125V, and the variance will sock more (or less) power to your power tubes accordingly.

The guy is full of shit and such a blatant lie says to me to avoid him like the plague.

First off the NOS Jan Philips are 100% compatible, you have to adjust the bias anyway so no big deal. Do be aware though that the amp will break up sooner, i.e, not as much clean headroom. I've seen voltages in excess of 470 in some amps. Remember, the schemo voltages are from the 110v era and readings will now be higher. Also be aware that the voltage variance is + to - 20% on top of that so there is lots of wiggle room.

The JAN NOS tubes can handle the higher voltages. Many of the modern tubes cannot regardless of the

"GC" "WGC" ""GB" designation with "WGC" and "GB" being rated for lower voltages anyway. There is no true 5881 being produced right now. The Sovet and Tung Sols with the 5881 designation will fail at about 425 V on the plates. I learned the hard way rebuilding a couple of real 59 Bassman. That being said the Tung Sol 6l6GC STR, the TAD 6L6WGC-STR and JJ 6l6GC will cut the mustard in most BF/SF era amps.

Hope this helps.

[crunchee]

Thanx TONS, Brewmaster! That is what I figured, but was needing a bit of reassurance. Thanks again!

A P.S.: regarding the secondary question, why HAS US wall current increased over the years? Just curious. I'd think with all the emphasis on energy conservation nowadays, a lot of people would wonder about that.

[Brewmaster]

Back in the day 100-110v was adequate for the radio's, light bulbs, and small appliances that were being used. After WWII and the resulting manufacturing boom by the late 1950's household appliances, bigger refrigerators, Color TV, etc demand for higher voltages over longer distances increased tremendously. There was a debate between using 120 or 220 or so like the Euros but 120 was chosen because it is more efficient. There is a lot more to it than this, I'm just giving an overview off the top of my head.

[crunchee]

Cool, that makes sense! Thanks again, Brewmaster! I remember when I was stationed with the Navy on the W. coast of Japan, power there was 100W 50Hz. I didn't seem to have problems with wattage that I know of, but the Hertz (being 50Hz on the W. side of Japan instead of 60Hz...which apparently it is on the E. side of Japan, don't ask me why!) made my US market digital electric clock run MUCH slower, it lost about 2 hours a day. At least, that's what I remember it being the reason, I may be wrong about the Hertz business. Tombo was stationed over there, he may have run into this as well, too.