Hi all,
I have a couple of questions stemming from the restoration of a QRX-9001 and would welcome any input, especially from Quad Bob, since he has first hand knowledge of reworking this beast.
First off, I am fully recapping this unit (first of four that I own) and have hit a snag - there are eight 4.7uF bi-polar electrolytics with a rating of 80(!!)WVDC on the power supply board.
A search of the usual suspects (Digikey, Allied, Mouser, MCM) shows that nobody stocks bi-polar 'lytics rated over 50WVDC. MCM and Mouser have non-polar rated at 100VDC, but (and I must admit my ignorance here) I'm unsure if a non-polar can be subbed for a bi-polar. Anybody here have a definate anwer to this one, or a source for bi-polar caps rated at >80WVDC?
Ok, second question. As far as the decoder boards, I am contemplating replacing all the electrolytics with polypropylene caps, so I don't ever have to worry about the caps going south again.
As well, I've heard (although I'm not yet convinced) that poly caps improve the audio quality over electrolytics. I would be interested in any comments on whether this claim holds water, and if there is a particular brand of cap I should consider for it's superior characteristics.
TIA for any input
Kevin / The Sansuiman
I have a couple of questions stemming from the restoration of a QRX-9001 and would welcome any input, especially from Quad Bob, since he has first hand knowledge of reworking this beast.
First off, I am fully recapping this unit (first of four that I own) and have hit a snag - there are eight 4.7uF bi-polar electrolytics with a rating of 80(!!)WVDC on the power supply board.
A search of the usual suspects (Digikey, Allied, Mouser, MCM) shows that nobody stocks bi-polar 'lytics rated over 50WVDC. MCM and Mouser have non-polar rated at 100VDC, but (and I must admit my ignorance here) I'm unsure if a non-polar can be subbed for a bi-polar. Anybody here have a definate anwer to this one, or a source for bi-polar caps rated at >80WVDC?
Ok, second question. As far as the decoder boards, I am contemplating replacing all the electrolytics with polypropylene caps, so I don't ever have to worry about the caps going south again.
As well, I've heard (although I'm not yet convinced) that poly caps improve the audio quality over electrolytics. I would be interested in any comments on whether this claim holds water, and if there is a particular brand of cap I should consider for it's superior characteristics.
TIA for any input
Kevin / The Sansuiman