Help me improve Rega P2

If you choose to upgrade the cartridge keep in mind that you should consider how well the load capacitance the cartridge would see in your setup matches the cartridge manufacturer's recommended range of load capacitance. Your phono stage has a rather high input capacitance of 220 pf. I would guess that the phono cable and turntable wiring adds roughly another 200 pf or so to that, bringing the total to the vicinity of 400 or 450 pf or thereabouts.

While that will be a suitable match for many MM cartridges, it is too high to be sonically optimal with many others. Including the Ortofons that have been mentioned (for which the recommended load capacitance range is 150 to 300 pf), and the Shure M97XE (for which the recommended load capacitance range is 200 to 300 pf). And I would be cautious about choosing any cartridge for which the manufacturer doesn't provide a load capacitance recommendation.

The manufacturer's recommendation for your present cartridge, btw, is 150 to 400 pf, which is a wider range than is usually specified. Just speculating, but perhaps Goldring's standards in deriving that spec are not as stringent as those of some of the other manufacturers.

Good luck. Regards,
-- Al

Thanks, Mesch! I've seen numerous indications over the years that load capacitance recommendations for moving magnet cartridges are based on the total of all capacitances between the cartridge pins and the phono stage input (inclusive of the latter). Which would seem to make sense since the wiring capacitance can vary greatly depending on the particular cable type and its length. And if the turntable has a connector on the rear (which I believe the P2 does not have) it would of course be readily possible for the user to substitute cables and thereby vary the capacitance over a wide range. The 200 pf figure, btw, was just my rough guess in this particular situation, and substitution of a relatively short cable having particularly low capacitance per unit length (were that practical on the particular turntable) could easily cut that in half.

Also, I took a look at the brochure and the user manual for the Blue Point No. 2 at sumikoaudio.net and I didn't see any load capacitance recommendation indicated. But I can't recall ever seeing a recommendation as low as 50 to 100 pf for any other cartridge. Also, the BP2 is of course an HOMC rather than a MM, and while I don't have a good feel for the sensitivity of typical HOMC's to load capacitance, I suspect it is likely to be dissimilar to that of MM's.

Best regards, and happy new year!
-- Al

Correction to my previous post: FWIW, I just noticed this somewhat ambiguous statement in the text of the manual for the Blue Point No. 2:

Note: If your receiver or pre-amp has capacitance loading capabilities, a Sumiko high output moving coil cartridges should be loaded with a value no higher than 200pf, and ideally below 100pf.

My guess is, again, that that refers to total capacitance including the wiring, but given the wording it's hard to say for sure.

Best regards,
-- Al

Thanks, Marty (Viridian). It should be noted, though, that the DB Systems kit, or any other similar kit, can only add capacitance, not reduce it.

But we tend to focus on those things that we can measure, rather than those that we can't.

True enough, in many cases. And I personally have never experimented with intentionally mismatching load capacitance of MM's relative to the manufacturer's recommendation, to see how much difference it would make. But I see it this way: Audio is a pursuit in which many people concern themselves with unexplainable, unpredictable, and often dubious minutiae, even in some cases to the extent of things like which way a fuse is oriented. Given that, why introduce an explainable, predictable, and known inaccuracy into the system, notwithstanding the possibility that it **might** be minor in degree, or perhaps even subjectively preferable? And if it should happen to be subjectively preferable, chances are it is compensating for a problem elsewhere, which ideally and hopefully should be found and fixed rather than compensated for.

Best regards,
-- Al

Matt, Rega may be all about being simple to use. But the unusually high input capacitance of the OP's phono stage makes the use of that phono stage not so simple, if one places any faith in the load capacitance recommendations provided by the cartridge manufacturers.

I doubt that any of us are in a position to characterize the degree to which sonics are likely to be affected by the capacitance mismatch which is almost certain to occur with the 2M Blue (to a greater or lesser degree depending on the unknown capacitance of the phono cable and turntable wiring). But as I said earlier, "why introduce an explainable, predictable, and known inaccuracy into the system, notwithstanding the possibility that it **might** be minor in degree, or perhaps even subjectively preferable?"

Regards,
-- Al

Phasecorrect, the OP's present cartridge has a recommended load capacitance range of 150 to 400 pf. The 2M Blue that was suggested has a recommended load capacitance range of 150 to only 300 pf. My rough estimate of approximately how much load capacitance his equipment presents to whatever cartridge he uses was 400 to 450 pf.

... so I don't feel the cap mismatch is a major issue in this circumstance...maybe in a higher end system...

You may be right, or you may not be. I don't think any of us is in a position to say for sure. My point is why take a chance? There are lots of MM's and HOMC's out there for which the manufacturer recommends higher load capacitances than what is recommended for the 2M, as a perusal of the cartridge listings at NeedleDoctor.com and other sellers will show. The suggestion by Mesch to call them was a good one.

Regards,
-- Al

Thanks Marty (Viridian). I happen to be very familiar with that paper. While it can often be useful and informative, it also oversimplifies and overlooks a number of things.

Relevant to what is being discussed here, it conveys the impression that what will be optimal for a MM is reduction of load capacitance to negligible levels. The rationale being that minimization of load capacitance, in addition to maximizing bandwidth, will eliminate what might otherwise be a resonant peak in frequency response falling within or affecting the audible range of frequencies. What that doesn't take into account, however, are the effects on frequency response of the mechanical characteristics of the cartridge. Specifically, as I understand it, for MM's elimination of that resonant peak will typically result in significant frequency response rolloff in the upper treble region. While if some amount of resonant peaking is allowed that rolloff will be "filled in" by the resonant peak.

At the same time, though, as he indicates too much capacitance can also cause premature rolloff, while also causing the resonant peak to be excessively large and to occur at frequencies that are excessively low. Therefore both too little capacitance and too much capacitance will, for MM's, result in uneven frequency response and/or premature rolloff in the treble region. Which is why the cartridge manufacturers provide, or at least should provide, a recommended RANGE of load capacitance.

Best regards,
-- Al