Pioneer SA 9500II Weak right channel

[haggy38]

Hi Guys,

I need some expert advice here, my Pioneer sa9500II has developed an estrange behaviour, when is cold the right channel is weaker compare with the left one, after 10 minutes when the amplifier gets warmer, it gets even. This symptom happens in both A and B speaker selection, any idea where to start looking?


Gustavo

 

[markthefixer]

Deoxit all the switches. Especially the tape monitors. classic symptoms.

You COULD experiment and see if toggling (rapidly - i.e. exercising) the front panel switches (tone on/off, filters on/off, muting and all the Tape) pinpoints the CURRENT culprit.

ALSO pull, clean and reinsert the pre-out to power amp-in jumpers in the back.

 

[haggy38]

Thanks, will deoxit and exercise all switches.



Gustavo

 

[KingBubba]

Hopefully your volume control is not scratchy and in need of a cleaning also. The Alps pots are well built, but a bit of a PITA to get into. To do it correctly, the pot should be removed from the unit and disassembled. This was way too much for me when I redid my 9500II. The body is a series of plates held together by four full length bolts. What I ended up doing was to very carefully loosen the bolts ever so slightly; just enough to be able to get my Deoxit into each of the layers. It worked for me. Unless yours is scratchy, I would not mess with it. If it is scratchy, then go at it slow and carefully. Good luck with a great old integrated amp. I hope the issues are helped by the cleaning.

 

[haggy38]

HI,

The amplifier sounds pretty good without any scratchy sound fortunately, Ill just use deoxit everything. Thanks.


Gustavo

 

[Jon1982]

While not an expert, I would suspect a capacitor... seems that one of their failure modes is to gradually come 'back to life' a bit as they warm up / get some current passed through them.

 

[haggy38]

Well guys,

I've cleaned everything with deoxit, still the same symptom, probably a bad cap or transistor?... where?..


Gustavo