MM vs MI vs MC

[Thomas_A]

Looking at the cables in my setup they are specified at 28 pF for the tonearm itself and 100 pF for the tonearm to preamp cable. The Muffsy preamp has a choice to add any extra capacitance but has no capacitor at the moment. This gives 128 pF + a few extra on preamp input. Lower than that is difficult unless you change cable.

 

[dlaloum]

Do you think there's any truth at all to certain claims that lower inductance in itself should make for a better cart? Apart from being less sensitive to capacitance. In the case of the Excel carts (and most others), the low output TOTL body has slightly better channel balance and separation - according to specs - but obviously the separation is equally good here (actually even slightly better on the other channel for the high output)...

I think the market the high inductance cartridges are aimed for, are perhaps less discerning, or just less "picky" about those details...

Also the high inductance cartridges are usually at a much lower price point - mostly I believe, due to the much more basic needle and cantilever fitted... so yes, you are more likely to find channel mismatches, as the QA is probably to lower standards...

With some body types that are readily available for chump change (shures, at's, ortofons) it is worthwhile getting a bunch of them and testing them for channel matching to get the best exemplars... also worth keeping an eye on the off-brand OEM'd versions... eg: Digitrac = OM

 

[dlaloum]

Looking at the cables in my setup they are specified at 28 pF for the tonearm itself and 100 pF for the tonearm to preamp cable. The Muffsy preamp has a choice to add any extra capacitance but has no capacitor at the moment. This gives 128 pF + a few extra on preamp input. Lower than that is difficult unless you change cable.

I used a shorter than standard cable to get capacitance down to circa 60pf total for measurement and experimentation purposes - it also means the phono stage has to be right next to the TT, which is sometimes awkward.

 

[eliash]

I think the market the high inductance cartridges are aimed for, are perhaps less discerning, or just less "picky" about those details...

Also the high inductance cartridges are usually at a much lower price point - mostly I believe, due to the much more basic needle and cantilever fitted... so yes, you are more likely to find channel mismatches, as the QA is probably to lower standards...

...consider the Nagaoka´s great MP500 with 800mH coils (Sh tip/boron cantilever). Not a cheap one, it is around 800bucks.
In addition you need to do everything to bring the cap load down to a minimum to enjoy its performance. Had to build a minimum length low cap cable (from mech. modified RG-180) and kick out all the RFI caps in the preamp to reach a total cart loading of 110pF...

 

[morillon]

I used a shorter than standard cable to get capacitance down to circa 60pf total for measurement and experimentation purposes - it also means the phono stage has to be right next to the TT, which is sometimes awkward.

yes...
my point was modestly just that...
looking a little, low capacitance cable, short length, no input capacitance or very little prephono, it is quite easy to go below 80(-100) cumulative pico.. .
for your measuring batteries " at asr " (essentially mm) seems a good basis....allowing you to really play on these values...
;-)
ps
would be the opportunity to actually observe the impact of these games, the orders of magnitude etc, on these cartdriges of the type of these low inductance excel..interesting....
(ps bis
we once encountered some cartdriges which were rather adapted to 100pico, low, but these were designed for a charge at 100k...)

 

[dlaloum]

ps
would be the opportunity to actually observe the impact of these games, the orders of magnitude etc, on these cartdriges of the type of these low inductance excel..interesting....
(ps bis
we once encountered some cartdriges which were rather adapted to 100pico, low, but these were designed for a charge at 100k...)

I agree, many cartridges do better when you also adjust the resistive load... My experiments ended up with some cartridges optimised as low as 27kohm...

And during the "golden age" some manufacturers specified the resistive load as a range... not simply as 47k

Once you make inductance, resistance and capacitance variable - you then have a lot more flexibility with the tuning of the cartridge, and matching the load to the specific stylus fitted.

P.S.: there can be substantial variations between styli from the same manufacturer and model ... I have 2 Jico SAS styli, and the effective mass is sufficiently different between them to vary the resonant frequency, one is 14kHz the other is 16kHz - and that means that the loading for best response has to be different.... (or in todays age of electrickery.... adjust using electronic EQ instead!)

 

[dlaloum]

...consider the Nagaoka´s great MP500 with 800mH coils (Sh tip/boron cantilever). Not a cheap one, it is around 800bucks.
In addition you need to do everything to bring the cap load down to a minimum to enjoy its performance. Had to build a minimum length low cap cable (from mech. modified RG-180) and kick out all the RFI caps in the preamp to reach a total cart loading of 110pF...

That is a very high inductance for an upper end MM!!
Do you have any measurements of it? I would love to know where the cantilever resonance sits... and whether it is a heavier stylus than one would expect given the boron cantilever, and therefore the higher inductance to balance? From a design perspective, a high inductance would result in a rolled off high end, if the cantilever resonance was well up outside the audible zone... but if there is a strong resonance within the audio range that needs to be tamed, then the high inductance might make sense....

Curious...

 

[melloncolliecat]

Official Nagaoka measurements can be found here: https://forums.stevehoffman.tv/threads/nagaoka-frequency-measurements-of-all-6-carts.776313/

 

[morillon]

I agree, many cartridges do better when you also adjust the resistive load... My experiments ended up with some cartridges optimised as low as 27kohm...

And during the "golden age" some manufacturers specified the resistive load as a range... not simply as 47k

Once you make inductance, resistance and capacitance variable - you then have a lot more flexibility with the tuning of the cartridge, and matching the load to the specific stylus fitted.

P.S.: there can be substantial variations between styli from the same manufacturer and model ... I have 2 Jico SAS styli, and the effective mass is sufficiently different between them to vary the resonant frequency, one is 14kHz the other is 16kHz - and that means that the loading for best response has to be different.... (or in todays age of electrickery.... adjust using electronic EQ instead!)

funny ..I was looking this morning at the data from a large Denon Mi 70s integrated...one mm input at 50k a second at 30k..(and one mc 150ohm)....
(too bad no 100k that we sometimes encounter)

 

[USER]

Official Nagaoka measurements can be found here: https://forums.stevehoffman.tv/threads/nagaoka-frequency-measurements-of-all-6-carts.776313/

I wonder what test record they used. All other measurements I have seen show something quite different. Simulation also agrees with them.

MM vs MI vs MC

Even worse, vinyl playback is loaded with cues anyway. I see a difference in FR, it's just really small. We're also not seeing what's happening above 15k as the charts are cutoff for some reason. Last, I don't have a baseline for your loading. 0-100 may seem like a large change, but what if...

audiosciencereview.com

Nagaoka MP-500 and MP-50 Generators - Page 2- Vinyl Engine

www.vinylengine.com

MM vs MI vs MC

Nice MM vs MC vs MI illustrations I found

www.audiosciencereview.com

 

[eliash]

That is a very high inductance for an upper end MM!!
Do you have any measurements of it? I would love to know where the cantilever resonance sits... and whether it is a heavier stylus than one would expect given the boron cantilever, and therefore the higher inductance to balance? From a design perspective, a high inductance would result in a rolled off high end, if the cantilever resonance was well up outside the audible zone... but if there is a strong resonance within the audio range that needs to be tamed, then the high inductance might make sense....

Curious...

Regarding measurements I did go only until 10KHz with my old dhfi test record. Beyond, this one, an old RCA and a new HiFi news record show completely different HF results, so I would not rely on any of them...but up to 10KHz the dhifi measurements sound credible in comparison with digital listening, no significant frequency response deviation measured here (around 2dB range).
Going that low in capacitance has its reason in Nagaoka´s 150pF recommendation and some RLC simulations, which should be buried somewhere in this thread month ago. Actually its high inductance is hidden quite well by Nagaoka, the 800mH base on my own (verified) measurement, not disturbed by the coils´ large ohmic resistance...anyway, tracking at decent force, distortion, performance over temperature and channel separation are fine, it sounds exactly like digital with comparable mastered material on a SME309 9" arm @1.5g.

Btw. Thanks for the freq. response link @melloncolliecat!

One late remark, a generic Sh tip shows a slight HF (>16KHz @33rpm) drop compared to a MR tip at inner record radii, could be that Nagaoka tunes this drop a bit by the LC resonance.