Leestereo's Restoration/Upgrade Of A Sansui AU-717

[Jérôme29]

I checked TR04,08, D02 and TR03,07, D01 they are all good KSC992 ECB in right orientation, anyway i change D01 and D02 with new paire of 1N4148.
For the transistor i put the old one 2SA750 (TR07,08) and 2SA726(TR03,04).
Powered on the amplifier, everythings good and this time the DC offset doesn't move when i crank up the volume pot!!
I put on all the cover and try to play a song but this time no sound.......
mesure the voltage it's better but not enought apparently.... send a picture of mesurement

TR09,10,11,12 are KSC1845
TR01,02,05,06,13,14 are KSC992
Now TR03,04 are 2SA726
TR07,08 are 2SA750

I finally find my mistake, after checking all the resistors R23;24;25;26 were 330K instead of 330R.....
Now with the right resistors everything work perfectly!
Thanks to all guys who helped me
The 717 are back to life

 

[Aleksei77]

I used NOS Rifa 124 PEG 470uf on driver board, bought 8 of them to get 4 ones in specs, sealed them with glue and protected them with tape soldered them and they give a good bass punch and musicality tho lack just a little bit in details but great vintage tone if anyone interested.

 

[Aleksei77]

the rifa peg 124 combined with epcos b41821 33uf 63v sounds great

 

[TupolevFan]

the rifa peg 124 combined with epcos b41821 33uf 63v sounds great

Isn't it peg124 is axial cap ? how the heck you installed it on a 717 driwer board?

 

[Aleksei77]

Isn't it peg124 is axial cap ? how the heck you installed it on a 717 driwer board?

LOL, the legs of the axial caps are quite long, just sand the old oxidated terminals, i wrapped the caps in eletric tape and after soldering and protected the legs with more eletric tape to avoid acidentally toutching other components, i can send a pic. my tech put TOPMAY 1000uf and the amplifier was just sounding horrible. if topmay was a good brand would be called TOPSEPTEMBER, just to add i set the 1k pot and calibrated to 28MV instead of 20mv to get more audiophile sound.

 

[PF Sound]

LOL, the legs of the axial caps are quite long, just sand the old oxidated terminals, i wrapped the caps in eletric tape and after soldering and protected the legs with more eletric tape to avoid acidentally toutching other components, i can send a pic. my tech put TOPMAY 1000uf and the amplifier was just sounding horrible. if topmay was a good brand would be called TOPSEPTEMBER, just to add i set the 1k pot and calibrated to 28MV instead of 20mv to get more audiophile sound.

Not sure I understand the need to do this. There are still plenty of quality radial caps that easily fit the board with no sanding or taping needed. Are you just not able to order those parts?

 

[Aleksei77]

Not sure I understand the need to do this. There are still plenty of quality radial caps that easily fit the board with no sanding or taping needed. Are you just not able to order those parts?

Yes.. live in Brazil difficult to get decent caps for good prize, you only find general purpose here.

but vintage caps are different in some way of new caps.. not saying better they are different.