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CARY 2A3 CATASTROPHE

gadget73 said:
That wasn't really a comment on the quality of the tube so much as the quality of the socket and the base. No keys, so it relies purely on the pin size to prevent it being plugged in wrong. If the fit is wrong somewhere accidents happen.

I suspect you won't get much noise about this from most of us because somewhere along the line, we've all probably done something similar. If you've never made a mistake in life, you probably haven't ever done much :)
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Gadget is right and i bet that socket is Chinese made. I found that they have a very sloppy tolerance hence you were able to actually install the 2a3 with the pins touching the socket contacts instead of the socket stopping you. You should probably install usa made sockets, still available if you search, and hopefully the rest of the amp is not badly damaged. cheers.
 
That amp may be too old to have Chinese sockets, but on my 2A3 amp, which has Chinese ceramic sockets, I did exactly the same thing, but somehow decided to double check before turning it on because I noticed the logo faced the wrong way.

I have a pair of old stock USA sockets for my next build which look the same as the Chinese sockets, but are way tighter and are impossible to insert the tube wrong into.
 
To the O.P: don't feel too guilty, the problem is not with you but with the poor quality (chinese ?) ceramic sockets. The pin holes are too large and there's allways the possibility to inadvertently insert the tube the wrong way if you exert a little too much force and don't look at it closely. With good quality U.S made (Johnson) sockets this could never happen. This happened to me once (and I consider myself as an experienced tech) when in a hurry I inserted a brand new 300B the wrong way. Results: a few sparks, a dead tube, and two burned out resistors. Since that experience I'm very careful and advise other users of such amps to allways check tube orientation twice before powering up the amp.
As far as the damages to your amp are concerned , it could be nothing too serious (a fuse or burned out resistor) or someting much more severe (damaged transformer...) but the former situation is much more likely. Needless to say, your tube is dead.
 
For homebrew old production really is nice, but I can definitely understand that new mfg can't rely on stocks of old parts. Sometimes there just isn't any choice in the matter. I don't honestly know if anyone is making a high quality 4 pin these days. Seems there could be a market for it.
 
gadget73 said:
For homebrew old production really is nice, but I can definitely understand that new mfg can't rely on stocks of old parts. Sometimes there just isn't any choice in the matter. I don't honestly know if anyone is making a high quality 4 pin these days. Seems there could be a market for it.
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There's a number of quality alternatives which are currently in production.

In the early 1990s the old amphenol sockets were still in production, they were just expensive. No real excuse for using the the Chinese sockets besides cost.
 
The assumption is that these are Chinese made sockets in the OP's amp. Since the amp dates to 1990, there's a better than even chance they aren't M.I.C. Can the OP confirm one way or another?
 
Put a skunk stripe down the middle of the tube base, as you look at it from the front of the amp. This way you will always know the pins are properly aligned as you put the tube in the socket.
 
I am pretty sure that during the 90s chinese made sockets were available. If the tubes were available the tube sockets were also available.
 
bimasta said:
Good idea — but I'm lucky, Peter. I live in LA, a friend is a Cary dealer, does his own servicing, and he said he can fix it for me. No shipping, a "friendly" discount — I'll go to him if I can't fix it myself.
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This seems like a situation where it's hard to make an argument for doing anything but letting the professional fix it. But you should still let us see some photos, because photos are always good.:D
 
Did something similar w SE KT88 (missing guide pin) http://www.tubeaudiolab.com/id177.html
Per Min's suggestion, cleaned socket, replaced tube. As power wires had emitted magic smoke, I removed PT, and inspected the damage.
I was lucky. Re insulated wires and got correct volts.
Had to replace a resister or two, and 50uf 100v lytic, was then back in black.
 
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