The Pioneer SX-1250 is an incredible receiver. It's a very special unit because Pioneer were not trying to build the "world's most powerful receiver", they designed the world's
best receiver. 1976, and it is, to this day, probably the best "pre power wars" receiver you can buy. It sounds better than their stupendously powerful SX-1980.
And yes, ironically, I have both of them here, right in my lab at the same time. Same owner- and he also regards the SX-1250 as the better sounding unit. The SX-1250 outperforms the SX-1980 in every parameter except sheer power. Happy to show pics if you don't believe me.
As for "refurbishment", that's a tough question. You cannot just replace a bunch of components in an SX-1250 and declare it "restored". Anyone who does, doesn't know what he is doing. It's a huge job. Many hours. Honestly, it's not worth it if you have to pay $80/hr+ parts. You have to pick your battles.
You certainly don't throw a bag of dodgy Fairchild/OM transistors at the unit and expect it to perform well. The Japanese transistors used were infinitely better than the crap people are sticking in vintage gear in 2025. You rebuild the pres, power and PSUs with original OEM transistors or you leave it well alone. Do not second guess the designers. Can you measure the THD, FR and IMD? If you can't, what the hell are you doing in there in the first place? Go mow your lawn, cook a BBQ with some amazing ribs, but stay out of classic HiFi. Put down the soldering iron and walk away.
Too many classic receivers have been destroyed by clowns who couldn't be bothered actually tracking down the proper devices instead of just plugging in a number into "transistors R US" and using totally unsuited and crap "equivalents".
I've banned (refused) repair/restorations on most classic gear unless it is 100% original.
