Sony TA-8650 filter cap replacement?

[vintagejapan]

I would check heatsink temp, not top cover.
Can you hold your hand on it with 100mv bias?

There is 6 Vfets in each heatsink. The size of the heatsink is almost the same as that of one Vfet of Yamaha B-1 and even with the chimneys will not cool them adequately
From my experience Sony manuals are full of errors. I cannot hear any difference in sound if biased 100mv or 30mv.

 

[Andriyol82]

yes

 

[vintagejapan]

Sony updated the bias settings for 4560, 5650 and 5550.

 

[stillastills]

I am looking for some ideas on removing preamp power supply double capacitor to replace with new caps. (I was able to remove the power amp power supply cap in preparation for replacement.) The clamp that holds the preamp power supply cap has a screw to loosen that I am not able to get the required grip (with different sets of needle nose pliers), and the screws that hold the clamp to the chassis are not accessible. The only thing I can think of is to cut into the clamp screw with a dremel.

I would also like to know if anyone has rebuilt the electronic speaker protection (Muting circuit shown on schematic??).

Any help is appreciated.

 

[Nashou66]

use a socket i would guess.

Nashou

 

[stillastills]

use a socket i would guess.

Nashou

That might work, I will check my socket set. The screw shaft is pretty deep, perhaps I can cut it down first w the dremel. Will let you know.

Ok. Used 9/32 socket with pliers to loosen the screw so that I could remove the capacitor from the clamp. Socket wrench itself would not fit in the space available.

Thank you.