Using a metal can 6V6 in a modern amp (VHT Special 6)

[PeanutNore]

I've recently acquired a "Delco" branded metal can 6V6 that I believe was made by RCA and I'd like to give it a shot, but I'm not sure if it's safe to do. The amp that I'd be using it in is a VHT special 6. They make the schematic available here : http://www.vhtamp.com/pdf/VHT_Specia...ic_5-17-10.pdf

I know that the metal can 6V6s have pin 1 connected to the can, while the glass ones have no connection. The amp has pin 1 tied to pin 8 (cathode). Is this a problem? I expect the bias and plate characteristics to be within the limits of the tube, so this is the only thing I'm really worried about besides it possibly getting too hot (but I can always point a fan at it). So basically I'm just wondering if I can leave pin 1 (can) connected to the cathode, or if I should snip it and connect it to ground or just isolate it.

[Leo_Gnardo]

If the B+ is say 350V or less, might get away with it. And the metal shell will be at cathode potential. I've gotten mild shocks from metal tubes. Don't think you have much choice on whether the metal shell is attached to pin 1 or not.

[PeanutNore]

Don't think you have much choice on whether the metal shell is attached to pin 1 or not.

Yeah, my plan is to open up the amp and make the change to the tube socket, either disconnecting pin 1 from pin 8 and grounding pin 1, or leaving pin 1 floating. I'm fairly certain I'll need to disconnect them, though, because if the tube retainer thing touches the metal can it would ground the cathode other wise, and it's a cathode biased amp so that would be pretty bad.

[deci belle]

I just rip pin 1 out of the metal jacket 6v6s before I use them at 370v in a 5E3.

[PeanutNore]

Thought I'd give an update - I pried pin 1 off that sucker (tough S.O.B. too) and it works great. Now the amp breaks up a lot harder, and a bit sooner. At the same time it feels less compressed so even with a lot of dirt dialed in it's really easy to clean up just by easing off with my picking. All in all it's a great little old tube, much better than the chinese glass that was in there before.

[Chuck H]

The only trouble I've had with the metal power tubes is that they tend to go microphonic sooner than glass. That and they are often gassy when I'm digging through salvage and testing them. They're also untouchable (not in a good sense!). Since metal conducts heat better than glass the envelope enclosure can literally leave a blister if you try to touch it bare handed! Other than these precautions... If it sounds good, DO IT!