Hi, do you remember the values of each Mylar bypass caps you used for the six 470uF ones? Did you use another value for these? And are you using metallized polypros to bypass the smoothing caps (uF value?) for 18V Zeners and for regulators, too? I see they are 100nF/100V, but did you keep same stock values for the electrolytics?
I remember I once used a couple of 39nF Mylar caps bypassing C605, C606 in one 317 that I used for experiments, but it was a while ago.
Hi
@Karl vd Berg, dont remember the exact values, but as I mentioned to
@MRPerformance, these were common values. did not change the electrolytic values much or at all. Sansui picked pretty good values for low ripple.
The main thing I did was make sure I was using genuine Nichicon UPW caps and not some fake, there are many out there. The UPW type is ultra low ESR and high ripple. I installed new Zeners too, since that was cheap insurance.
Should also note, on the Sansuis, where the glue had not eaten through the cap lead, some of the factory installed power supply caps still tested quite good (ESR and capacitance meas). So would speculate storage conditions would have a lot to do with how well the caps age or don't age.
As I side note, should add I have a few Sansui Au-217s. One of them, I use for my computer audio speakers on an internet machine. Have an audiophile 192 PCI card I route the analog outputs to the aux input on the 217. I recapped that 217 seven years ago. Since then, its has been on 24/7, with not a single issue from it. I also added all sorts of bypass caps to it, maybe even more than the 317s I have done, and its a sweet sounding amp as long as you use it within its power range. If I can find the pics, anyone who is interested in upgrading their 217, will be happy to pass along.
best
