Leestereo's Restoration and Upgrade Of A Sansui AU-919

[Hyperion]

Hyperion would you say that polystyrene
(if possible to be found ) is a better option to the C0G/NPO or it doesn’t worth the “hustle” find them ?

Good question - Yes, the 'Noble' polystyrenes being a case in point, but Noble are no more and capacitor companies don't seem to think they are worth making, at least not in wire ended style - so nicely done by Noble who made these capacitors 'radial style' - to reduce lead inductance.

 

[Leestereo]

The original AU-919 pictures have been restored (without the Photobucket watermark).

 

[Heinrich76]

Amazing restoration Lee thank you, I have followed this and now my AUD-907 sounds awesome. I found the MM phono stage volume to be much lower when playing vinyl compared when playing from line-in using the Wiim mini (set to 1vrms for it’s output). Is that normal?

 

[Hyperion]

I found the MM phono stage volume to be much lower when playing vinyl compared when playing from line-in using the Wiim mini (set to 1vrms for it’s output). Is that normal?

Doesn't sound right to me...

Use the AUX input for the Wiim, and compare the signal level at the Flat Amp input (or the main amp input), when using either the Wiim or the MM Phono input - while obviously not identical I believe they should be reasonably similar. (note you can reduce the gain of the system by switching out the 16dB gain provided by the Flat Amp using the 'Jump' switch).

 

[Zaemon]

The capacitors C19, C20, C45 and C46 were originally rated at 3.3µF/63V and their replacements were low ESR types rated at 47µF/63V.

Is this a typo and it should be 4,7uf/63V. Why 47uf if correct?
On driver board.

Edit: I see bigger caps on the finished board. Suppose 47uf/63V is correct then