As long as they physically fit, not a problem at all. They'll give your power supply a little more power reserve when you play your music loud.
Thanks babblefish! Following your advice today I replaced the old main filter caps C501 - C502 (original 8000uF/50v) by 10,000uF/50v EPCOS. Distance between +/- original pins is 15mm and the new ones 9mm. I drilled new holes, with new caps in position pins were bent and they matched the +/- copper paths. No sweat! just solder them! Tested and no smoke!!!
Also, following the advice of user ccheath on thread: SX-780 recap list? (02-25-2009, 03:20 PM )
http://www.audiokarma.org/forums/showpost.php?p=2533561&postcount=9 suggested:
Replaced all the caps outside the signal path: No difference.
Low Filter (also a coupling between preamp and main amp)
Replaced C227, C228 0.22/50 & C229, C230 2.2/50: Little noticeable difference
Preamp:
Replaced C207, C208 1/50: There is very noticeable difference.
Replaced C217, C218 4.7/50: There is very noticeable difference.
Loudness:
Changed from stock ceramics to WIMA film
C203, C204 330pf & C205, C206 0.022uf: Sounds smoother while ceramics sounded fuzzier.
So I went and replaced only the Preamp caps as follows:
- Preamp C207- C208 (orig 1uF/50v) by 1uF/63v
- Preamp C217 - C218 (orig 4.7 uF/25v) by 4.7/50V
Also, just in case, and following other threads advice:
- Resoldered Q25 2SD712 regulator transitor
Before closing the unit did:
- DC balance of power amplifers VR5(left channel) Pin9 & GND / VR6 (right channel) Pin6 & GND : about 8mV volt each with no speakers connected, volume at zero and aux (with no input connected), couldn't get 0mV. Tricky pots to adjust! :scratch2: Guess 8mV is a good value.
After that checked:
- DC speaker output voltage measured. Left the receiver on for 30 minutes with speakers not connected, selector in aux input and nothing connected, tone at mid position, no loudness, balance at center, vol at minimum. Used to digital meters connected to speaker outputs. Volatges measured:
left channel 9 mV , right channel 5 mV :thmbsp:
Again, according to other thread:
0 - 15mV: Damn good!! If you read '0V', you may have a capacitor output, or your meter is set wrong
16mV - 50mV: An acceptable value, especially at the lower end of this range. 2nd harmonic distortion is probably twice to four times what manufacturer's spec calls for at higher frequencies. Probably not audible, as the distortion is mostly in the upper octaves. At the upper end of this range I begin to raise an eyebrow.
50 - 85mV: Something is certainly amiss, and while this is not enough to put your speakers or equipment in jeopardy, the amp is running nowhere near where it should. I'd venture to guess that most of the DC-coupled amps that are in use by forum members here fall into this range.
100mV to ?: A high enough voltage will cause the DC protection to kick in. This happens at a level determined by the designer, but is usually equivalent to about a diode drop (600mV)or so. Needless to say, if you are listening to an amp with 100mV or more of DC offset, you have no idea what the amp really is supposed to sound like. Indeed, some amps without a differential input are actually designed to have a bit of DC at the outputs, but this is triple-rare, and I don't think anyone here owns one. (in my book it's piss-poor design, but if you can sell it WTH..)
My notes:
-It seems eveything is working fine.
-Changing those caps on the preamp section improved bass and treble quite a lot a lot!
-New filter caps (2x 10,000uF) somehow gave a better and clearer output, also no light trembling at high volume.
-The only thing I'm not satisfied is the loudness section, perhaps should change caps also. There's little difference turning loudness on. It's there but not as impressive as I remember when the unit was new (32 years ago!!! ;-)
That's all for now. All comments, advices, remarks, will be greatly appreciated!
Regards and thanks! Andy.
