18-04-2025, 04:35 PM
I'm in the process of a S-99 recon and have a general question as to how far do you need to go for a satisfactory outcome?
I have taken the power pcb out and removed all the cap's. The electrolytics are not original (the amp is about 65 years old) made by D.C.C., they are all out of spec by about 40%!. I have taken the lower value 'Hunts' out and a few 'Dublilier', again all out 40/50%.
I will be replacing these with the 'cheapo' black and white & red one's available on mass from Ebay etc. This may horrify the purists but I have always used these and they 'sound' fine (this is the 6th S-99 I have done).
I have generally ignored resistors unless they show signs of heat damage and rarely had to open up again to replace one. However with the pcb out, this time I have measured all the resistors with the following results=
Of the 32 on the board excluding the wire wound which are all good, 13 are within 20%, 10 20-30%, 5 30-40% and 4 way out.
I don't want to 'poke' this board about too much because it's old and I worry about lifting tracks etc. I will replace the one's 40%plus
but what about the others?.
The pre-amp board will be next, that looks a mess, the big plessy cap has split in two!.
An interesting observation is the big 60+75uf cap from the tranny, the previous owner replaced it with a 75+100+100, so he must of, some how wired the 100's in series? but I can't see how he could of done it from the same pot. ( I can't check how he wired it as I've ripped it all out with the power board).
I have a S-99 in daily use for the last couple of years, never replaced a resistor just all the cap's and it sounds a treat!.
I have taken the power pcb out and removed all the cap's. The electrolytics are not original (the amp is about 65 years old) made by D.C.C., they are all out of spec by about 40%!. I have taken the lower value 'Hunts' out and a few 'Dublilier', again all out 40/50%.
I will be replacing these with the 'cheapo' black and white & red one's available on mass from Ebay etc. This may horrify the purists but I have always used these and they 'sound' fine (this is the 6th S-99 I have done).
I have generally ignored resistors unless they show signs of heat damage and rarely had to open up again to replace one. However with the pcb out, this time I have measured all the resistors with the following results=
Of the 32 on the board excluding the wire wound which are all good, 13 are within 20%, 10 20-30%, 5 30-40% and 4 way out.
I don't want to 'poke' this board about too much because it's old and I worry about lifting tracks etc. I will replace the one's 40%plus
but what about the others?.
The pre-amp board will be next, that looks a mess, the big plessy cap has split in two!.
An interesting observation is the big 60+75uf cap from the tranny, the previous owner replaced it with a 75+100+100, so he must of, some how wired the 100's in series? but I can't see how he could of done it from the same pot. ( I can't check how he wired it as I've ripped it all out with the power board).
I have a S-99 in daily use for the last couple of years, never replaced a resistor just all the cap's and it sounds a treat!.
