Capacitors in Cary PH302 phono amp

Interesting comments regarding the Mundorf S/O caps.
I'm not hearing the same inconsistency with dynamics in the Cary phono amp.
Perhaps the caps have degraded over time(?)

The Clarity MR caps are supposed to be very good - if I were not getting such superb sound with the Mundorfs, I might be tempted to try them.

FWIW, I did conduct the temp measurement experiment that I mentioned above.
Ambient temp was 20ºC.
My phono amp reached stasis after about 1.5hrs. - the temp measured at the cap surface (closest to the tube) was then 32ºC. The probe hanging in free space inside the phono amp case was 29-30ºC (a bit higher than I thought it would be, given the coolness of the exterior).
In any case, I don't think 2ºC is significant enough to warrant looking into heat shields etc.
I also removed the top cover to measure glass temp on the the 6SL7 - but as soon as the lid was removed all temps dropped and the glass only read 28-29ºC.
For comparison the (exposed) 6NIP driver valves in my power amp had a glass temp of 47ºC and the (exposed) 6550A power tubes had a glass temp of 72ºC(!).
The Cary phono amp offers a relatively benign environment for electronic components....if the Mundorf's can't survive here then, IMO, they probably don't belong in any active devices.

The Mundorfs like the Clarity Cap MRs were mounted to the spruce board that is essentially the chassis mount for the Altmanm Dac . The whole assembly is then mounted to and tensioned to a custom one off Sistrum platform. All the components of the Altmann including the coupling caps are in free air. Temperature variation in an environment like this would be nill even though the MR's have a higher temp rating by 15 degrees C. I doubt the Mundorfs broke down in free air use after only 2 years. The Clarity MR's maybe superior in their dynamic presentation because of their design and construction based on resonant energy transfer. That's how I hear and see the stage in front of me. Tom

Tom, my note on the temp experiment was meant to address Reb and Dover's concerns above - not meaning to draw any conclusion regarding your setup.
That said, I have read some reports where users have stated the Mundorf S/O sound has changed after extended use >300hrs - not necessarily related to heat. Who knows?
In any case I have heard nothing but good reports regarding teh Clarity MR caps, they were on my shortlist and something I may try in the future.
Cheers - Paul

Paul

I saw that your setup is tubed based and mine is not. The reference to maximum temperature rating was in reference to the 2 caps in proximity to high heat exposure. Your measurements predict that your cap of choice will work just fine. Cool. Good listening.
Tom

I debated about posting this as it may be of limited general interest, but thought it may be of use to owners of the Cary PH302.

Following Reb and Dover's advice above I finally got to swapping out the Cary Audio 1 oil cap in the PS of the 302. While I was satisfied with the sound of the Cary with the output caps substituted, it did have a softness on transients that wasn't entirely to my liking. The integrated phono of the ARC SP16 was superior in this regard.
I was curious about whether this cap (not directly in the signal path) would have much effect. Due to space requirements choice of substitution caps was somewhat limited. The Multicap PPFXS (polypropylene/tinfoil) I chose fit easily and had a fairly good rep for PSU use. I used the same value .22uF/600V, though the voltage rating is overkill in this application.

The improvement in sound (after run in) was beyond my expectations.
Transient reproduction is massively improved - but without etch or over-emphasis. The soundstage is more open and tranparent with instruments and performers much more lifelike and 'in the room'. The phono amp retains its engaging beauty but now has realistic attack and decay.

There doesn't seem to be any downside, but agressive recordings don't get the same 'massaging' as they did with the oil cap in place. I don't think there is any doubt that the Multicap produces the more accurate and realistic sound in my system though.

Thanks again to Reb and Dover for the heads up regarding this substitution.