crisping a tube socket?

[madwing]

i continue with the rebuild of my pilot sa-232, and have removed all the parts from one of the 12ax7 sockets. i've also removed all the extra solder, and the wire bits left from clipping the wrapped wire ends.

there seems to be a lot of dark brown gunk at the base of each pin. it *looks* like cooked rosin, and flakes off the tube socket easily (i will take a brush and a blower to it tonight). the thought occurred to me it could actually be the socket material, and that by heating the pins with my 40-watt ratshack iron i crisped the socket (melted it, singed it, whatever).

is this possible? or is it probably cooked rosin from the original soldering job?

 

[RetroHacker]

I would bet on the cooked rosin. Tube sockets are made from pretty hardy stuff. Is this a bakelite socket or phenolic wafer? The phenolic wafer sockets can sometimes discolor and get "crummy" and burnt, but it's hard to do. Do the other sockets look like this? I've seen sockets get burnt and crumbled, but never from a soldering iron - only from prolonged heat from tubes. And the 12AX7 is just a dinky little dual triode - it doesn't generate enough heat by itself.

Why have you removed all of the components from it? Are you having problems with the socket? If you have any doubts about the socket, go ahead and replace it now, while you have all the components off of it.

-Ian

 

[jrsh92]

This happens to me all the time, but it's never caused a tube socket to stop functioning. I think it's rosin.

 

[madwing]

I would bet on the cooked rosin. Tube sockets are made from pretty hardy stuff. Is this a bakelite socket or phenolic wafer? The phenolic wafer sockets can sometimes discolor and get "crummy" and burnt, but it's hard to do. Do the other sockets look like this? I've seen sockets get burnt and crumbled, but never from a soldering iron - only from prolonged heat from tubes. And the 12AX7 is just a dinky little dual triode - it doesn't generate enough heat by itself.

Why have you removed all of the components from it? Are you having problems with the socket? If you have any doubts about the socket, go ahead and replace it now, while you have all the components off of it.

-Ian

ian, thanks. there's similar dark browning on all the other sockets, but just not as much. i think it's a bakelite socket, brown and looks like it would be.

i removed all the components because i am replacing them all. resistors and caps, plus some crispy wires. now with your answer, and the other above, i have no doubts it's the rosin.