I purchased a ~1970s vintage 8500 II Pioneer Amplifier from Japan. I am wondering if anyone here does restoration on older equipment and has recommendations on replacing the transformers vs using it on a step-down transformer. The Japanese unit is designed for 100 vac at 150 watts. I assume I can run the unit on my Variac and see what I think.
It looks like (from the service manual) I could replace the existing transformers with 120 to 35-volt transformers (I'll verify the voltage when I have a unit). Using Anetk toroids would be pretty cost-effective if they fit. I don't know if there is an advantage of one option over the other. In any case, I would keep the existing transformers in case I want to put it back to stock.
Any advice would be appreciated. I do plan to re-cap the electrolytic and fix whatever else I find. I'll probably preemptively replace a few transistors that are known to fail as well.
It looks like (from the service manual) I could replace the existing transformers with 120 to 35-volt transformers (I'll verify the voltage when I have a unit). Using Anetk toroids would be pretty cost-effective if they fit. I don't know if there is an advantage of one option over the other. In any case, I would keep the existing transformers in case I want to put it back to stock.
Any advice would be appreciated. I do plan to re-cap the electrolytic and fix whatever else I find. I'll probably preemptively replace a few transistors that are known to fail as well.
Original transformers from US based sellers are available on eBay - I would place those and have a unit as near as possible to its original state.
Should I decide to go for replacements (toroidals etc) I would consider placing them in an external box - less noise inside the amplifier.
Should I decide to go for replacements (toroidals etc) I would consider placing them in an external box - less noise inside the amplifier.
I do like the idea of keeping it as original as possible. Is there any reason to believe the original transformers would be quieter? I always thought toroids were better in this regard.
You might find this old thread interesting, about converting a 100V Japanese to 120V, using a relatively small conversion transformer.
https://www.diyaudio.com/community/...tage-change-100v-to-120v.393989/#post-7224651
https://www.diyaudio.com/community/...tage-change-100v-to-120v.393989/#post-7224651
He mentioned rebuild and these older Pioneers make outstanding platforms for very high end new amplifiers and turntable RIAA Eq.