Quad 303 capacitor conundrum

[kenworthy]

I have recently bought a second quad 303 to go with my existing one. As always I have completed a full restoration all caps,transistors,trimmers changed bias and voltage reset. Anyway being a sunday when I was doing this I was limited for the output caps so bought a set of Samwha for audio 6800uf 63v from Maplin (already had power supply caps Vishay). I was not expecting a great deal but thought they would do the job for a day or two. Anyway to my surprise they sound excellent and better than the VISHAY BC caps I put in my other 303 a month ago. To rule out anything I swapped the caps between the two amps and suddenly the other amp was sounding just as good. The Vishays and Samwhas are the same capacitance and voltage.

Anyway in view of the bad press Samwha have had for failing and leakage in Samsung televisions I want to get a more reliable cap and seek everyone advice on what they have used in their 303's. Apologies for the length of the thread and thanks in advance for any ideas.

 

[neiljadman]

IME the leakage and failure in Samsung TVs is caused by the fact that Samsung used 12/16v rated parts on a 20 v power rail. My son's TV failed at 13 months - almost a month to the day after the 1 year warranty expired. Having replaced the one failed cap with a 25v rated part it is still running perfectly some three years later.

As for the 303, I have had great success with 4,700uF/100v Cornell Dubelier caps and like them in this output application. I didn't find that moving up to 6,800uF provided any additional benefit. But they were no more expensive either. So if you like the Samwhas stick with them - they are more than adequately rated for the job and I see no reason why they should should prove unreliable.