Capacitor Performance ~ High Voltage vs. Low Voltage?

Could someone please advise whether it might be detrimental to sound quality to use a higher than required voltage capacitor in place of a lower voltage one?

I have a nice Philips TDA1541 tube DAC which around the DAC chip has some small 20v 68uF OsCon electrolytic capacitors, and I'm thinking of replacing these with some large 630v 68uF Solen polypropylene types. There is also potential to make this change with caps in the tube output stage.

Someone told me that the Solens could be a backward step due to their large size and high voltage, that there may be issues with lack of saturation or something??

Thanks,

Steve M.
 
In general, OsCon caps are some of the more premium electrolytics around for the very low ESR at high frequencies they offer. They excel in SMPS filtering. Used on lots of PCs.
I don't think voltage rating matters much with respect to film non-polar caps. If this was clear cut, the answer would be easier. Try it and get back to us......
 
Oscon caps have excellent high frequency performance, but not as good as films. The voltage is a minor issue. What I'd worry about is that replacing them with films might cause ringing because the films have such low DF at high frequencies that they'll form a resonant circuit with any inductance. The films will also be physically larger, and that's not a good thing for predictable HF performance. This is a case where, unless you have the test equipment to check it, you should leave well enough alone.
 
Someone told me that the Solens could be a backward step due to their large size and high voltage, that there may be issues with lack of saturation or something??

OsCons are used for decoupling of digital circuits due to excellent ESR and small physical size - small size means low inductance. Your suggestion of large caps is indeed a step backwards owing to large capacitors having significantly higher series inductance. Just as Conrad says, best leave well alone. You might be able to improve on the decoupling performance of OsCons by paralleling some small SMT caps with them, but its a long-shot and a TDA1541 is relatively old technology (read slow digital) so doesn't require super-low ESR and ESL.