I do repairs and check ups of vintage audio equipment in Raleigh NC, however I don't know particular upgrade you're talking about. If upgrade menu provided, I'll certainly be able to implement it. I've also never been dealing with remote customers. It was all local the whole time.
You can PM me for more info
Other than that, I'd go for repairs to either Guitar Center or smaller local music store where they have techie that services guitar amps. Your Golden tube is much less sophisticated than guitar amp.
You can PM me for more info
Other than that, I'd go for repairs to either Guitar Center or smaller local music store where they have techie that services guitar amps. Your Golden tube is much less sophisticated than guitar amp.