Metal Can 6V6Y ?

[greg788]

I assume it's safe to use a metal can 6V6Y in any 6V6 application -- plug and play? I read something about one pin internally tied to ground, might as well confirm before wasting $50 ... anyone try these - what do they sound like? Vacuum Tube Valley (magazine #10) wasn't too complimentary about them for hi fi or even guitar applications but I'm always one to try anything

[Paul Birkeland]

Really really old 6V6s have pin 1 tied to the exterior metal of the tube.  This would put about 12V DC on the metal portion of the tube which isn't the end of the world and there's an insulator on the bottom of these tubes so that can't touch the chassis.  If you're concerned about it, the white wire that goes to pins 1/8 can be altered to just go to pin 8, then run a wire from pin 1 on each socket to one of the center lugs of a 5 lug strip touching the chassis.

Most often pin 1 on a 6V6 connects to nothing, so this isn't a concern. 

[Mucker]

I posted some relevant information I am sure you will read in another thread. A question for Paul. It seems a metal tube would offer better immunity from outside interference than a glass tube. Is this plausible?

[Paul Birkeland]

The metal envelope may indeed do just that.

[Doc B.]

I'll throw in that some old glass 6V6s have Aquadag - a conductive graphite coating - inside the envelope. This was done for shielding and, at least in CRTs, it also created a path for the return of the electrons being shot from the gun.

[Mucker]

Ah, very interesting .....

[Mucker]

Thought these look interesting. Clean and good printing.

https://tubeworldexpress.com/products/recommended-pair-6v6-rca-metal-can-nos-1976-38ma-and-39ma

[adeep42]

Fascinated by the threads on Black metal 6V6s. Got a pair of NOS RCA's on eBay. They've been running for several days. I'm quite pleased. The sound is very smooth and lush.

[Mucker]

Looks great! They are fine tubes IMO.

[greg788]

I bought a pair of early 60s RCA 6V6Y. My subjective evaluation is that they're very "solid state" or "modern" sounding, meaning transparent and resolving. Strings "pop" a bit, for example, like solid state amplification tends to do. I expected that going in because the metal cans are low distortion typically, plus no microphonics since no glass.

But, they're smooth sounding, not ruthless. They're worth a try since they veer so far to an extreme.

Overall, various 6V6, at least the ones I've tried, sound more similar than dissimilar over different vintages, manufacturers, etc. Word on the street is that the current Russian 6V6, esp. Tungsol and Gold Lion, are also pretty good (never tried them)

[Mucker]

Found a pair of NOS Motorola tubes for cheap on eBay. They sound great, as good as any of the glass I have. I don't find them to sound solid state at all.