Sorado Tube socket arcing

[wb5gmk]

My friends son has a SUNN SORADO with factory discrete diodes, the multisection can plus two 20uf CDE 600v axials, all appear original.  His complaint is its no longer clean above 6, must have went higher.  I checked the 6550 tubes GE and RCA on an old Slyvania tester they read in the upper middle GOOD 100, 110 no leaks no shorts. However I noted on one tube socket underneath as white haze and charring between pins 2 and 3 the heater and the plate.  Oddly one socket is slotted pins, the other wraparound pins definitely of different manufacturer, both riveted as original. One doesnt hold the tube real well.

Has anyone had tube socket failures?  Will try to see leakage compare pin 2 to pin 3, socket to socket with a VTVM. If confirmed. With the high voltage, what is best replacement?
Thanks - Mike

[mckinnon audio]

  Hi there,sockets do fail from time to time,mostly due to tube removal,people tend to wiggle the tubes out instead of pulling straight out.The wrap around pin types need to be retensioned every so often.Make sure the power is off and use a jeweler's screwdriver or something similar and insert it in by the pin and twist/pry to retension it.Arcing from the plate to the heater makes me think a tube shorted and damaged the socket.As far as replacments go,porcelin sockets won't arc but they aren't stock in Sunn gear.Look for some heavy duty types at any of the parts wholesale places.Hope this is of some help,good luck,Mel.

[loudthud]

Riveted octal sockets? All my Sunn's have Amphenol wavy washer types. Try to find some ceramic sockets. They won't arc.

[wb5gmk]

I appreciate the replies. Could be it had a very professional repair, as it does have a hammond output transformer.  The rivets look exactly like the rest of the chassis.  I did notice on the pictures on this forum that the sockets were snap in.  Read most of the posts on this forum, most interesting history.

Thanks again.