Sansui AU-X911dg restoration

[quadmatrix82]

To remove the rod , you'll have to remove faceplate. Then it comes off along with the pushbutton.
Make sure you order all new trimmers. Also bear in mind there are a couple hidden in the front pcb behind the faceplate ,they are preamp dc offset.
The volume knob is hard fixed , but if you insist it will slide off . Don't be afraid of it.
Good luck. It's not a heavy work amp to recap . Actually it's pretty straight forward.

Thanks for the tips! I’ll try remove the plate tonight…the knob was very stuck on but will give it another go. So far looks all original inside and clean

 

[quadmatrix82]

Thanks for the tips! I’ll try remove the plate tonight…the knob was very stuck on but will give it another go. So far looks all original inside and clean

I got the faceplate off the volume knob was very stubborn but came off…as for the rod it seems well placed in the plastic shaft is that piece glued or does the plastic piece come off with the rod? Hard to take a photo due to lack of access…

 

[quadmatrix82]

I got it off needed a force the whole plastic piece comes off for those next time…

 

[quadmatrix82]

Main amp modules done with new capacitors zener diodes and trim pots - should I change the 47ohm resistors? The 1000uf pictured will need replacing as not enough clearance on one side just a few mm too large oh well another mouser order…

 

[quadmatrix82]

I have some Nichicon super gold 15000uf capacitors here - quick eye I think they’ll fit in - are these too large a upgrade from the original 10000uf?

 

[JOMARK911]

I have some Nichicon super gold 15000uf capacitors here - quick eye I think they’ll fit in - are these too large a upgrade from the original 10000uf?

They are fine , once the voltage is ok. You could even quadruple the capacitance bank with no problem.

 

[JOMARK911]

Main amp modules done with new capacitors zener diodes and trim pots - should I change the 47ohm resistors? The 1000uf pictured will need replacing as not enough clearance on one side just a few mm too large oh well another mouser order…

Yes change those , and yes the 47ohm resistors too.
You could even drop in a pair of 1000μf , on the driver board next to the already existing ones. They are just marked , but not used on 911,711.
You will just need to drill a couple of holes on the pcb for the caps to be soldered . It is used on the DR MR and all alphas .

 

[quadmatrix82]

may do the cap upgrade another time! but good to know

Yes change those , and yes the 47ohm resistors too.
You could even drop in a pair of 1000μf , on the driver board next to the already existing ones. They are just marked , but not used on 911,711.
You will just need to drill a couple of holes on the pcb for the caps to be soldered . It is used on the DR MR and all alphas .

 

[quadmatrix82]

Made progress today, the EQ board and DAC board almost finished - found some caps with green legs argh!!

 

[quadmatrix82]

i

Yes change those , and yes the 47ohm resistors too.
You could even drop in a pair of 1000μf , on the driver board next to the already existing ones. They are just marked , but not used on 911,711.
You will just need to drill a couple of holes on the pcb for the caps to be soldered . It is used on the DR MR and all alphas .

ordered some flameproof film caps - I'll change the resistors when they arrive cheers!

 

[quadmatrix82]

Starting on the power supply is this normal? Looks like a yellow wire is cut ?

 

[quadmatrix82]

Looking at the power supply there is a 2200uf muse capacitor - can this be changed with a low impedance or low esr cap? Or should it be an audio grade one?

 

[quadmatrix82]

Making progress! Are the 10e2 diodes worth changing ? The capacitors were all leaky the board looks good other than some dry joints

 

[JOMARK911]

I don't recall the yellow cable. Don't know.
The muse cap is just fine , it is audio grade after all.
You have leaking caps ? funny.
I haven't got time to fiddle with them
Yes if they are leaky go on and change them .

 

[quadmatrix82]

I don't recall the yellow cable. Don't know.
The muse cap is just fine , it is audio grade after all.
You have leaking caps ? funny.
I haven't got time to fiddle with them
Yes if they are leaky go on and change them .

thanks I found a lot of leaky caps - does that audio muse cap really need to be a audio cap given it’s in the power supply? I don’t have any audio caps in this value so wondering if I can use a low esr or low impedance cap instead?

 

[JOMARK911]

If you have to change it yes go ahead.

 

[quadmatrix82]

If you have to change it yes go ahead.

Thanks I ended up placing another mouser order to get a muse cap however more importantly FYI everyone the fuse resistors on the main amp board are 4.7 ohm and not 47 ohm as printed in the service manual.

 

[quadmatrix82]

What is considered the best way to clean the faceplate on these models? Go nec the glossy finger prints is there a preferred solution/application?

 

[Hyperion]

does that audio muse cap really need to be a audio cap given it’s in the power supply?

Not normally recommended to use Audio Grade capacitors in a PSU. (Audio grade usually 85°C, & not low ESR - better if temp handling is higher i.e. 105°C, and for a PSU low ESR /and /or low leakage is a good thing).

I don’t have any audio caps in this value so wondering if I can use a low esr or low impedance cap instead?

Yes, much better.

 

[quadmatrix82]

Not normally recommended to use Audio Grade capacitors in a PSU. (Audio grade usually 85°C, & not low ESR - better if temp handling is higher i.e. 105°C, and for a PSU low ESR /and /or low leakage is a good thing).
Yes, much better.

Thanks Hyperion this is what I thought and was wondering why the original cap here is a Nichicon muse? Location c24…I have a low esr one I’ll use instead