Traynor 7027 sub?

[drewl]

Retubing/refurbing an old YBA3 Custom Special Traynor which I believe came with 7027's originally, or so the schem says.

Which you think I should go with, EL34's or 6L6's?
Thanks.

[Enzo]

You can buy reissue 7027s these days - I think they are just repackaged 6L6s. A 6L6 could plug into a 7027 socket, but since there are extra inner conections on the 7027, the chassis could be wired expecting them. For example, the screens in a 7027 connect to both pins 1 and 4, instead of just 4. The amp could be wired with the screen supplyto pin 1. Also, they could send the screen supply to pin 4 like always, but then runa wire from pin 1 to the other socket's pin 4.

You should be able to tell visually in a couple seconds if any wiring is different. 6L6s would be closer than EL34s. Or just get 7027s.

[drewl]

The sockets are okay, I was just wondering which would match the output tranny better.
Someone had already put 4 1k screen resistors in and it had 2 EL34's so I was thinking of going with some 6CA7's like the later versions.
Some even used 6K6's.

[Rob Mercure]

Drewl,

The SED 6L6GCs would be a good choice as long as the socket connections match as Enzo stated. But if it's wired for an EL34 then the 7027 should produce fireworks. And I suspect that the circuit would quickly eat up a 6K6 which is more 6V6-"ish."

Rob

[jrfrond]

7027's were design for B+ voltage ranges of 600+ VDC. New 6L6GC's can take about 525VDC, and I would not trust a 6V6GT or even 6V6GTA, the ruggedized version, to go over 400VDC. So, depending on your B+ requirements, you can use 6L6GC, or even 6550. I am almost positive that the "reissue" 7027's are just repinned 6L6GC's anyway.

[Gtr_tech]

I think he meant 6KG6 which the early Traynor Super Custom Specials used.

[Gtr_tech]

Oh...and JJ 6L6s work great in place of 7027s. I put them in Ampegs all the time and they hang just fine. My YBA3 specs Sylvania 6CA7s....but rawks hard with EL34s. I'd prefer the 6CA7s but...you know the rest.....

[drewl]

I think he meant 6KG6 which the early Traynor Super Custom Specials used.

Yes, the early ones had 6K6's according to the schems, I know most of the Traynors had 6CA7's for their classic sound but since this version of the YBA3 had 7027's I was wondering which would match the impedance best.
This thing only puts out about 80w.
anyway, thanks for the opinions.

[Gtr_tech]

6*KG*6, not 6K6. A 6K6 is a small octal pwr tube akin to a 6AQ5, but not as heavy. They look like 6V6s. They were used as a rev pan driver in the old Fender stand alone reverb units. A 6KG6 is a large heavy duty TV sweep tube with a plate cap connection on top like an 807 and a novar base. Not even remotely compatible.

https://www.tubeworld.com/6kg6.jpg
http://www.gstube.com/photo/3276.jpg

[Robert M. Martinelli]

if it's wired for an EL34 then the 7027 should produce fireworks.
Rob

If rewiring for EL34s IMHO it is mandatory to put a label close to the tubes' sockets with a warning that clearly indicates that the amp is now wired for EL34s and it cannot accept 7027s any longer, otherwise, as Rob said, someone could eyewitness an anticipated 4th of july.....

Hmmm.... I was wondering....what about a switch on pin one to be able to change tubes' type without rewiring? It would need to be located in a "hidden" or recessed area to avoid unwanted switching, and properly labeled, but it could be a good idea, just in case one doesn't have 7027s handy.

Regards

Bob