Mystery Of Red Plating

The most common cause is the tube itself fails.

Sometimes the socket fails with the tube. If high voltages (+500V) are involved, sometimes the socket can develop internal arcing. This is why ceramic sockets are used in higher power situations, as they are immune to this problem. Of course a socket that is arcing must be replaced.

Good luck with the repairs!

I had to wait 8 months to get in line at ARC. I think the repair cost with shipping was $3,000. The Audiogon Blue Book says my VT130 is only worth $3000.  Gee thanks! 

The ARC guy told me since the spamdemic "everybody" was taking their old gear out of mothball and sending it in for refurb- hence the wait. ARC must be making a killing on restoring old gear.

A musician buddy of mine told me to call the music store in at the local mall. They would know of local technicians that worked on tube amps (Fender mostly). 

Lo and behold they were right!  A dude named Matt Garcia had a store front repair shop called Garcia Amplification in old Myrtle Beach SC. He fixed the unit for $300 all in!  What a deal!  Moral of the story: Support your local electronics man.

2 Sylvania NOS 12BH7As $60

2 5K ceramic resistors       $5

Materials and Supplies     $25

Diagnose, test all 14 tubes, replace 3 resistors, 3 tubes, bias L&R, $210

Total cash out the door $300.  It took him a week.  

I had an amp red plate and it’s scary.   That’s why you should never leave a tube amp on if you’re not close by.   

Awesome ending.   There are still some good local techs , it’s finding them that’s a challenge