Capacitors in Cary PH302 phono amp

I've just bought a S/H Cary PH302 mk-2 phono amp.
I noticed that the 2 caps near front tubes, C15 & C16, appear to be different to the caps shown in the pictures on the Cary website.
Upon closer inspection it appears that these may have been changed by a previous owner. See pic below:
Cary PH302 Capacitors

The substituted caps(?) are Multicap PPMFX types, 1.0uF/200V.
I found a capacitor test that rates these caps very poorly.
My question is what were the original capacitor types and value.
Any suggestions for substitution, other than original?
In my ARC phono stage an upgrade from Multicap PPMFX to PPFXS and RTX was a big step up in SQ. From web images it appears that the original caps may have been Hovland or Auricap. You have room inside for a 630V cap such as ClarityCap MR--but that's just me. In any case, all other things being equal, SOME higher voltage caps will sound better due to considerations of capacitor construction unrelated to operating voltage.

ClarityCap OEM Sales
The MultiCap PPMFX metalized-'propylenes are their entry-level cap; they're not bad sounding, but any of their other caps will sound better. The best MC, the 'styrene RTX, is QUITE-good-sounding and about the least-expensive truly-hi-end cap around IMO.

Hi-end-cap choices are just like opinions--everybody's got at least one and most of us, more than that.

Do you know what the original value was? If you want to go with a REALLY hi-end cap such as the various Teflon-film caps, choosing the correct, SMALL capacitance will save you money and/or allow you to choose a higher-quality cap than otherwise.

So find out what that cap's load resistance is and also the input impedance of your line stage and we can help choose that value.
Thanks for the replies.
I don't know the type and value of the original cap - hopefully a ph302 owner will volunteer the information.
The input resistance of the my SP16 line stage is 50kohms.

Assuming the value of the substituted Multi-cap is correct - I was considering replacing with a 1uF 200V teflon cap, perhaps the Audience Aura T (they seem to get high praise and not quite as expensive as other teflon caps).

My other train of thought is to put it back to original (if I can find out what that is) - I assume Dennis Had would have tested various caps in that position and settled on his choice for a reason (hopefully because they sounded good).
Tobes, My experience with the original MIT caps you have are they are better than the older Hovland & Auricaps which are vague and murky - so I wouldn't go back to original. The RTX are very good, but word of warning, used in speaker crossover we have found the internal impedance/inductance characteristics were drifting. Discussions with Richard Marsh shed no light on why. We have compared these original MIT in both tube pre and speaker xover to Hovland ( H was murky ), Mundorf Supreme ( MIT had much better timing and around the same transparency - therefore MIT at 1/4 the price is way better value, Mundorf Silver and Oil ( this had much better timing than the Supreme and I would rate it better than the MIT ). My view is go for Mundorf Silver/Oil, Audio Note Copper Foil ( if you dont like silver ), or Teflon. Beware if you go Teflon - they take weeks to run in. Cheap option is go to MIT PPFXS.
Hmm thanks for your thoughts Dover.

Seems that MIT RTX caps are well thought of and regarded as a nice step up from the PPMFX. Economical too.

The Cary certainly sounds ok with the current PPMFX caps, but my feeling is that its not uniformly transparent across the frequency range. The caps may have nothing to do with this of course, but I'm curious to hear what a couple of well regarded Teflon caps might do for the sound. These seem to be universally praised for their transparency.
PPMFX is a very good base value capacitor by itself. Dont believe every shoot out that comes along on the internet. Bypassing that cap with an RTX or Russian FT-1 Teflon gets you excellent sound for little money outlay.
To quote J.C. Morrison from his blog: "cary audio does it like radio shack would have… in the 70′s, if they smoked crank and gambled on tractor pulls". My guess from the Cary products I've seen is that the original caps were Kimber Caps.
Well, I'm not sure which way to turn now...too many choices.

Maybe I'll steer clear of the expensive Teflon options and go for something in the middle ground.

In no particular order, looking here and elsewhere, these appear to be worthwhile trying and likely upgrade from Multicap PPMFX:

* Multicap RTX
* Clarity Cap MR
* Mundorf Mcap Silver/Oil

The cheapest option - RTX - would appear to be a 'safe' choice.

Dozens of other choices, but I fear my head might explode with the options.

Reb, found one of your posts elsewhere, is it your understanding that Cary use MIT PPMFX as stock parts - ie the caps in my PH302 may be stock for the Mk2 model? (The pic I was comparing my unit to on the Cary website appears to be a Mk1 model).
Tobes, I wouldn't lose too much sleep. My Marantz 7 still uses the original MIT caps I put in 10 years ago and it has seen off my ARC and Jadis preamps quite handily. The 3 caps you mention are all well regarded, what I know from experience is that both the RTX and Mundorf maintain the very good timing of the MIT PP... just read heaps and go with your gut instinct. You can always put the current caps back in if you dont like the result.
Can't go wrong with the Mundorf S/O caps IF you want to upgrade.
Ok, I've ordered both the RTX and the Mundorf Silver/Oil - that way I can experiment and it won't cost me the earth.

Thanks for all the helpful input.
Tobes - good luck and let us know how it goes. Will be interested in what you think, as it may be time to give my preamp a birthday as well.

The RTX at 1uf is physically a large capacitor and IME the larger value RTX caps tend to have a noticeable bass overhang. RTX is best used IMO in smaller values ie .15UF-.22uf as bypass capacitors. Your best of using the Mundorf full range and changing the order for the RTX to .15UF and using that as a bypass.
Thanks for the tip Reb.
Do you suggest using the RTX as a bypass on just the PPMFX or trying it on the Mundorf as well?
Maybe I'll get a couple of extra .15uF RTX caps to try with my SP16. It uses ARC branded 1uF Relcaps (labelled PP3MF) at the output.

Ironically, I changed a few things around tonight and have the Cary sounding much more to my liking. When I put it in the system a week ago I sat it on top of the SP16 to make it easy to compare the phono stages. Just tonight I've moved the preamp down a shelf and Cary now rests directly on the top (granite) shelf of my rack. This allowed me to experiment with different footers etc. Currently I have some old (Shun Mook!) steel spiked ebony footers under the Cary and I'm getting a marvelously spacious and dimensional soundstage with much better focus and presence than when it was plonked on the SP16. Probably doesn't hurt that the components are now spaced well apart either.
The Cary is whipping the SP16's phono stage big time now - much more spacious, airy and harmonically complex.

Will still be fun to see what the different caps will bring to the sound.
Hmm...Reb, the supplier I was buying the RTX from doesn't have 0.15uF listed, 0.10uF should be ok shouldn't it? Isn't the rule of thumb 1/10 main cap size?
They do have 0.22uF if you think that's more suited to bypass 1uF.
Tobes, high quality capacitors such as the Mundorf silver-oil in a relativly small 1uf value generally are not "candidates" for bypass as already they perform at a high level. However, this is a hobby and I encourage you to experiment. How else are you going to "learn" what works in a given piece of equipment?

The PPMFX perform as well as any SOA cap when bypassed with the proper bypass capacitor IME.

A .22UF RTX would be more suitable as a bypass on a 3-5UF cap IME. I would go ahead and order the .10UF RTX and use that as a bypass on the PPMFX.

What you should hear with the RTX bypass of the PPMFX is foremost a 3 dimensional soundstage (depth/width/height) That is the sonic signature of polystyrene. Secondly, the bass will take on greater definition and prat. While the highs will sound both more open and sweeter. Lastly, there will be more harmonic overtones and tonal depth.

I make extensive use of both polystyrene and teflon capacitor bypasses in my equipment- signal path and power supplies.
Thanks again Reb, Dover and others. I'll post back how things turn out.
Well I substituted the Mundorf silver/oil for the PPMFX caps - Wow, really nice improvement!

The Mundorf's, with only 10-15 hours of play, are more transparent from top to bottom and have great extension and 'air' while offering more refinement. The Cary sounds gorgeous and seems to have gained more 'speed' and neutrality. Voices sound stellar. Best of all it sounds even more musically engaging.

PH302 with Mundorf S/O

FYI Reb, I never received a reply to my (email) order for the RTX caps. Perhaps I should have chosen a supplier with online sales(?). Anyway I'm more than happy with the Mundorf caps and I don't think I'd want to play with bypassing the PPMFX now.
Tobes, well done, Just to emphasize Rebs comment on bypassing, I would not recommend bypassing the Mundorf as they are built as 2 capacitors in one body with interleaved windings to minimize inductance. Bypassing would probably negate the design.
Tobes - I just saw your photos - I would suggest you push the caps as far away as possible from the tubes to minimize heat transfer.
Dover, there is more of a gap than appears in the photo, about 4-5mm. I also stood the caps off the PCB - mainly because there is a resistor under their footprint.
Those 6SL7 tubes run really cool, hardly giving off any heat. The whole unit only uses 15W according to Cary (most of the heat seems to come from the 5AR4 rectifier tube). I doubt it gets much above ambient room temps inside the case.
The caps appear to be mounted too close to the 6SL7 tubes as Dover has noted. However, the glass envelope of the 6SL7 is where most of the heat is. The base just houses the pin-out, so your mounting position is probably fine.

FYI- An old trick when replacing passive components that take up room is to mount from the underside of the circuit board. Sometimes taller standoffs are needed to raise the board a sufficient height to fit the part. This would allow you to keep the leads short. ( and mount away from the tubes.
Reb, Dover, thanks for the concern. I had read about the Mundorf caps not liking heat, so I checked things out before mounting.

I've given the caps a little tweak - the distance to the 6SL7 tubes is 4mm. As you noted the caps are opposite the brown tube bases, not the glass envelope, and they approach the round base on a tangent. I think that gives plenty of breathing room.

If we were talking about a power tube in a hot amplifier chassis it might be different, but the envelopes on these tubes only run warm to touch.
You can read the specs for the 6SL7 here.
As you can see the plate dissipation for the tube is 1W max and the heater is using <2W - so <3W total per tube (most of which will dissipate from the glass envelope - which has substantially more area than say a similarly rated 12AX7, hence the lower glass temp I guess).
The PH302 has a rather big case with plenty of breathing room and the case itself gets barely warm...and that's only above the 5AR4 rectifier tube.

I don't believe this environment should pose any issue for any reasonably designed electronic component.

FWIW, the PH302's PCB mounts onto shallow standoffs to the bottom of the chassis - definitly no room to mount a cap like this on the bottom of the PCB.

Once again thanks for the input.
A closer look at the cap to tube distance after a little tweak to the left:

Mundorf silver/oil cap

I would buy a roll of automotive gasket material (the grey multi-ply sheet) Cut a square and stand it up between the capacitor and tube. In a tube cd player mod that I installed Mundorf caps close to the tubes. The gasket material blocked the heat. Without the gasket material, just too hot for the long term.
Hi Tobes - we must sound like a bunch of old women with our comments. Next step if you want to go further would be to replace any Solen's in the signal path. Even the MIT will easily surpass these in speed, timing, dynamics and your pre will just get better and better.

+1 to the above post.

To the left of the Mundorf appears to be a Cary "Audio One" oil capacitor (the long silver cap). That has to go, along with the Solens that are probably bypassing the nearby electrolytic caps.
Reb, Dover - what type of cap would you suggest to replace the .22uF 600V cap (long silver one in the PSU)? - I'd need something with similar form factor due to proximity to the Mundorf and the electolytic on the left. Could a bypass be used here?
Likewise what would you suggest to replace the Solen caps?
BTW, just for curiosity I'll run an experiment next weekend. I'm going to tape a temperature probe to the side of the Mundorf at the closest point to the tube. I'll monitor the temps periodically for 6-12hrs and see what sort of temp change I get. I'm betting it won't be big - probably close to the ambient change in the case - but we'll see.
Just looking in on this thread and felt the need to add my experience to the mix. I have been using Mundorf S/O's within my system in many positions for the last couple of years. Some are deep inside components and hard to reach. One that is very simple to perform a swap is on my hybrid Altmann Dac. The dac has a .47uf cap at the output of each channel. I chose a Clarity Cap MR to replace the Mundorf's.

My entire system is designed and built around the idea of resonance grounding. The MR caps were also designed with resonance control as the core factor to their construction.
Size was an issue as was price.

The MR is a much cleaner and more neutral cap in my particular device than was the S/O it replaced. The MR is much quieter yet insightful and more musical. The bass is smoother and more detailed and controlled. Vocal placement and outline is more defined but the biggest difference in these two caps are the dynamic contrasts. The Mundorf seems to have a staggering mind of its own. In the course of a recording I seemed to be grasping for the volume control wanting to turn it up or down depending on the sonic impulse. It was if I were waiting for someone to rap on the door or a drummer to knock over his cymbal all in the course of one recording. In contrast the MR is much more linear and stable in its tracking of the sudden impulses in the music is not at all compressed. The staging on the MR is more defined and detailed almost with a three d affect all with no perception of phase shift or crawl. I will be installing MR's in those other locations when time allows. Tom
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

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.
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.

Tobes, just for me to get it clear. You removed the $90 Audio 1 oil capacitor from the PSU and put instead a $5 Multicap...Cary is now promoting upgrades to older equipment and one of them is replacing in older tube preamps the original Kimber coupling capacitors with the .22uF 600V oil Audio 1's (two of them)....I gather, given your experience, that the Audio 1's are not optimal or suitable for power supply use but, it appears, they may work rather well as coupling capacitors (with some kind of bypass, I would assume). Love to hear what Rob and Dover could comment on this.
Tobes' findings didn't surprise me at all. I bought several Audio 1 oil caps from Cary many years ago and never found a place where I liked them. They had all the worst traits of oil caps (softness on leading edges, loose bass lacking in impact, and overall murky sound) without any benefits. In my opinion, etc. I am not a big fan of oil caps generally, but Jensen copper/oil caps sounded a lot better than the Audio 1s.
Yes (I think those PPFXS tin foil caps actually cost around $10).

And it was a much bigger improvement than changing the coupling caps to the Mundorf silver-oil.
Its baffling that a capacitor in the power supply could effect the sound so much. From the midrange up the sound is so much more realistic: more transparent/faster/cleaner. The oil cap dulls transients and softens/veils the sound.
NOTE: I've only heard the PS cap change with the Mundorf output caps - ie I didn't go back to assess the PS cap change on its own.

If you do some googling I think you'll find quite a few people don't like the Audio 1 oil caps for coupling duties either.
If they really cost $90, maybe I should put mine on ebay - that would pay for the Mundorfs!
Thanks, guys. Tobes, you are right, it is $5.44. for the 400V version, $8.45 for the 600V, at Parts ConneXion. You can see Audio 1's $90 price (charged by Cary,instalation extra) here:

Selectric,your negative experience with Audio 1's, was with Cary equipment, wasn't it? As you can see in link, Cary's pitch for them is quite forceful (being cynical, a sizable unused stock, perhaps? [wink]). Otherwise, afer all this years, would it be possible that Cary discovered some positive synergy using Audio 1's as coupling caps in early Cary tube preamps? As you can see in link, Cary is also offering the coupling cap mod using the Jensen copper/oil caps you mention (in my case it would be for a stock SLP 98 Cary tube preamp)...any further thoughts?

Thanks again!
FWIW, I could have used the 400V PPFXS but decided to replace with a cap of the same spec. Overkill in my application.

Cary have offered the Audio 1 oil caps as an 'upgrade' for some time - I think it was even an option on the SLP98. Again, try Googling for some results - I think you'll find reports of the same type of signature mentioned above.
Unless you like artificially softened transients/veiling, I'd steer away from those caps - there are plenty of other (cheaper) options to experiment with.
Thanks a lot, Tobes. Your input is most appreciated. Clearly, your experience has to be interpreted within the context of your basically analog/tube system,your speakers, your room, and within the frame of your very own preferences regarding sonic attributes.We both can have the exact same sonic attribute preferences but differences in our system components and room may warrant different tunig/tweaking, be it tube rolling or capacitor rolling, and any resulting possible combination of both, whether at the phono=pre, the preamp, the power amp, or any of the sources...not to mention the cable thing...maddening, isn't it!! I gather that if I combine your findings and advice with Upscale Audio's current promotional literature for the SLP-98 Formula 1 Edition (reading between the lines), the way for me to go is no coupling capacitors at all(the cheapest alternative!):
The F1 version will have the all features listed above. Factory-upgraded capacitors, hexfreds, and wiring. Next, we can get yours either with coupling caps or direct coupled. The typical SLP 98 you have read about in reviews has coupling caps. If you make it direct coupled, you will get more pop and snap at the top and bottom and the preamp will be extremely fast. While still tube, it will give you better bass slam. Better than any solid state preamp and will kick the snot out of these $10,000 "reference" preamps from other companies. Want a smoother, more textured sound? Keep the[oil] coupling caps and you will be in heaven.

Funny, Tobes, I think what you call "artificially soften transients/veiling," they call it "smother, more textured sound." Positive language,no doubt, for those that don't see any nagatives in such preference.
Ceph44, I don't have direct experience using the Audio 1 oil caps for coupling (though my impressions of the cap in a PS application seems to mirror those who have).

I'm sure they would be 'smooth' if that's what you're after - I was initially beguiled by the sound of the stock PH302.
However, if my experience is anything to go by, I'm guessing you'll eventually grow disatisfied with the sound because at the end of day it makes music sound less real. YMMV.
Thanks, Tobes. Your input is truly appreciated. I think we are on the same page...I don't like my sound unnaturally smooth, I go for tri-dimentional, accurate, transparent, natural sound, no extra detail, no euphonic colorations. After all the name of the game in its origins was--and still is for me--"Hi-Fidelty." A lot of gourmet, a la carte audio,away from ultimate fidelity, aimed at obtaining a sound that pleases (sounds nice)to the listener's is out there under the "audiophilia" banner.

In my particular case,I have several bona fide hi-end preamps (3 tubed and 2 solid state) and amps (2 tubed and 4 solid state, as well as DACs (1 tubed and 4 solid state). So, besides potential tube/capacitor rolling (not into op-amp rolling yet), I can mix and match components approching that evasive ultimate fidelity, gradually, like a shooter hitting the target and approching the bulls eye from different directions. I dare to surmise that you had initially too much of the tube recipe, and removing the oil capacitor's added "smothness" out of you Cary phono-pre, your main source, improved significantly for you the whole downstream performance of your very fine tube-centric system.

All the best, Cep44
06-21-11: Theaudiotweak
.....The MR is a much cleaner and more neutral cap in my particular device than was the S/O it replaced. The MR is much quieter yet insightful and more musical. The bass is smoother and more detailed and controlled. Vocal placement and outline is more defined but the biggest difference in these two caps are the dynamic contrasts. The Mundorf seems to have a staggering mind of its own. In the course of a recording I seemed to be grasping for the volume control wanting to turn it up or down depending on the sonic impulse. It was if I were waiting for someone to rap on the door or a drummer to knock over his cymbal all in the course of one recording. In contrast the MR is much more linear and stable in its tracking of the sudden impulses in the music is not at all compressed. The staging on the MR is more defined and detailed almost with a three d affect all with no perception of phase shift or crawl.......Tom

Tom, out of curiosity I tried the Clarity cap MR's - in both my SP16 preamp and the Cary PH302.
I didn't have the quirky dynamics you report with the Mundorf SIO but other than that I pretty much agree with your assessment.
I do find the Clarity caps more explosively dynamic than the Mundorfs as well as being more transparent, open and neutral. Soundstaging - width, depth, imaging, reproduction of space is no contest - Clarity caps all the way. I can't think of a single area where the SIO outperform the MR's but the former do exhibit a certain seductive liquidity that the Clarity caps don't have. However I much prefer the transparency and realism of the Clarity caps. The MR's also sound great - smooth, detailed and very open - from the start and even better after 10-20hrs - no long breakin required.
I wouldn't have thought it previously, but the SIO sound a bit colored and opaque by comparison.

Thanks for the heads-up.
Cheers, Paul

I have a Ph 302 MkII and was surfing the forums and came across your discussion of capacitors for the PH 302 -- in the end what modifications did you do to your Cary phono and please describe the changes --

I'd appreciate the info.

You can also send this to my email as well: