I had Audio Classics update my vintage tube tuner/preamp, they work on lots of brands, perhaps write them with questions, then call if you like their response. I dealt with Ryan there.
https://www.audioclassics.com/cat?cat=Amplifiers
aside from a resistor here, alignment there, the best thing they did for me was replace all the old corroded rca jacks with new gold plated ones.
https://www.audioclassics.com/cat?cat=Amplifiers
aside from a resistor here, alignment there, the best thing they did for me was replace all the old corroded rca jacks with new gold plated ones.