Rega are working on new MM PUs

[Craig B]

I agree, could accept a red or green, but looks must be better, they are in sharp competition with Nagaoka who's ugliest ?
In contrast I think Rega MC's looks the business.

Then again, these are like replaceable drill bits, or screw driver bits, how nice must they look in order to be useful tools?

 

[Craig B]

I hope they buck the trend for ultra low capacitance which would make them far easier to partner with a wide range of kit. I notice the Exact is specified as 100pF on the Rega site which is less than some arm leads, i.e. it implies a zero capacitance phono stage, which doesn’t exist! I don’t understand this trend as it is far easier to add capacitance than subtract it and most MMs in the 70s were 350-450pF as I recall.

Interestingly, this is what the Brother's Shure had to say about my first posh MM, the M95ED...

"OPTIMUM LOAD: 47,000 ohms resistance in parallel with 400 to 500 picofarads total capacitance per channel. (Load resistance can be as high as 100,000 ohms and total capacitance can be as low as 100 picofarads with only minor audible change.) Total capacitance includes the capacitances of the tone arm wiring, phono cables, and the amplifier input circuit."
​

I do recall that dear old Dad's Pioneer SX-434 receiver boasted 2.5mV input sensitivity and 50KOhm impedance on phono, however there was no phono input capacitance specified. Must have a look at the schematic some day. Regardless, that old Shure sure sounded good into that receiver to me; 'Tubular Bells' were tubular, and 'Time' was certainly full of clocks! More than that, there always seemed to be a lovely balance on vocals without much in the way of sibilance, nor any 'hissing steam' cymbals above. Certainly, the 0.2mil minor radius would have helped here (at least it more accurately transcribed point contact lines into my grooves!). Makes me wonder if these old cartridge models were just somewhat more forgiving because of there mechanical tuning, more so than what specific electrical loading might bring (or take away?).

Nice thing about Shure back then was that they published both coil inductance and DC resistance. Plugging the published 650mH into Hagerman's cartridge loading calculator returns 9.9kHz for 400pF, with 40.3kOhm suggested as optimum tuning (i.e. lowest amplitude peak). I've often wondered if a lower frequency electrical resonance peak wasn't a good thing when it came to fleshing out the mid-range? After all, the coils are essentially inductors (i.e. low pass filters) with a roll-off that needs countering. Put an audio-technica VM95 through, and it's 550mH coils with a doable 200pF puts the peak at 15.2kHz (with amplitude lowest via 52.4K); could this be a bit thinner sounding well into the upper mids here?

 

[PerF]

.. how nice must they look in order to be useful tools?

Ha-ha, useful and looks are not always compatible

 

[Robert]

Interestingly, this is what the Brother's Shure had to say about my first posh MM, the M95ED...

"OPTIMUM LOAD: 47,000 ohms resistance in parallel with 400 to 500 pico-farads total capacitance per channel. (Load resistance can be as high as 100,000 ohms and total capacitance can be as low as 100 picofarads with only minor audible change.) Total capacitance includes the capacitances of the tone arm wiring, phono cables, and the amplifier input circuit."
​

I do recall that dear old Dad's Pioneer SX-434 receiver boasted 2.5mV input sensitivity and 50KOhm impedance on phono, however there was no phono input capacitance specified. Must have a look at the schematic some day. Regardless, that old Shure sure sounded good into that receiver to me; 'Tubular Bells' were tubular, and 'Time' was certainly full of clocks! More than that, there always seemed to be a lovely balance on vocals without much in the way of sibilance, nor any 'hissing steam' cymbals above. Certainly, the 0.2mil minor radius would have helped here (at least it more accurately transcribed point contact lines into my grooves!). Makes me wonder if these old cartridge models were just somewhat more forgiving because of there mechanical tuning, more so than what specific electrical loading might bring (or take away?).

Nice thing about Shure back then was that they published both coil inductance and DC resistance. Plugging the published 650mH into Hagerman's cartridge loading calculator returns 9.9kHz for 400pF, with 40.3kOhm suggested as optimum tuning (i.e. lowest amplitude peak). I've often wondered if a lower frequency electrical resonance peak wasn't a good thing when it came to fleshing out the mid-range? After all, the coils are essentially inductors (i.e. low pass filters) with a roll-off that needs countering. Put an audio-technica VM95 through, and it's 550mH coils with a doable 200pF puts the peak at 15.2kHz (with amplitude lowest via 52.4K); could this be a bit thinner sounding well into the upper mids here?

One of the problems in having the resonant peak too low is that output falls away rapidly thereafter. So if the peaking is tuned to say 9K you're losing a lot of upper HF response.
I'd really like to see someone develop the Grado Fluxbridger principle which has inductance around one tenth that of typical MM at around 50mH. Fluxbridger generator, nice low mass tapered cantilever, ML stylus profile, compact solid body. What's not to like? - Eh Grado ?

 

[Craig B]

I hope they buck the trend for ultra low capacitance which would make them far easier to partner with a wide range of kit. I notice the Exact is specified as 100pF on the Rega site which is less than some arm leads, i.e. it implies a zero capacitance phono stage, which doesn’t exist! I don’t understand this trend as it is far easier to add capacitance than subtract it and most MMs in the 70s were 350-450pF as I recall.

This has triggered a memory, Tony, now confirmed, that Nagaoka used to list MP series 'Load capacity' as 100pF across the board; this within the old MPxx catalogue (omitted from the MPxxx one). They didn't list coil inductance, however, 'Inner impedance' was.

It makes one wonder if they were simply suggesting an absolute minimum of 100pF.

 

[Craig B]

One of the problems in having the resonant peak too low is that output falls away rapidly thereafter. So if the peaking is tuned to say 9K you're losing a lot of upper HF response.
I'd really like to see someone develop the Grado Fluxbridger principle which has inductance around one tenth that of typical MM at around 50mH. Fluxbridger generator, nice low mass tapered cantilever, ML stylus profile, compact solid body. What's not to like? - Eh Grado ?

Yes, I used to care about what was going on above 10kHz, too.

 

[Tony L]

This has triggered a memory, Tony, now confirmed, that Nagaoka used to list MP series 'Load capacity' as 100pF across the board; this within the old MPxx catalogue (omitted from the MPxxx one). They didn't list coil inductance, however, 'Inner impedance' was.

The thing I don’t understand (maybe Rob can explain) is MI designs like Nagaoka, Grado etc just don’t seem to care. My MP-500 seems happy with anything from the 39pF of my modified Quad 34 board up to whatever the Verdier has, which I suspect is about 400pF (as it sounds great with vintage Shure, awful with modern Ortofon). The modern MMs really seem to need careful dialling in whereas MI doesn’t based on my limited experience. In hindsight I’m sure this is why I preferred many other things (e.g. Nagaokas) to Linn’s AT-derived designs back in the ‘80s. I always disliked the K9 despite all the raves, it just sounded thin and toppy to me, and I bet that was a capacitance mismatch to Naim’s 470pF MM stage.

 

[Yank]

Wish list:

Low inductance (so cap insensitive)
Square body, like a Denon 103 but a bit smaller/slimmer for nice easy alignment
Green - it's the Rega signature colour after all. Make it a nice bottle green translucent perhaps
Namiki ML stylus profile on at least one of them

Replaceable stylus assembly

 

[Robert]

The thing I don’t understand (maybe Rob can explain) is MI designs like Nagaoka, Grado etc just don’t seem to care. My MP-500 seems happy with anything from the 39pF of my modified Quad 34 board up to whatever the Verdier has, which I suspect is about 400pF (as it sounds great with vintage Shure, awful with modern Ortofon). The modern MMs really seem to need careful dialling in whereas MI doesn’t based on my limited experience. In hindsight I’m sure this is why I preferred many other things (e.g. Nagaokas) to Linn’s AT-derived designs back in the ‘80s. I always disliked the K9 despite all the raves, it just sounded thin and toppy to me, and I bet that was a capacitance mismatch to Naim’s 470pF MZm stage.

Certainly the Grado designs have very low generator inductance. Not sure about the Nagaoka.

Mechanical damping is likely a factor also, some carts have little, some much more and this will impact severity of the tip mass resonance.
In addition to the electrical resonance you have that caused by the tip mass against the vinyl compliance.

 

[Robert]

Replaceable stylus assembly

Wash your mouth out

 

[davidsrsb]

Some experiments I have been making with my Clear Audio Concept show that the inductance is very variable with frequency - no surprise there.
I want Rega to do a MM that isn't a few dB down above 5 kHz before a big peak at 15 kHz
I would be happy to sacrifice a bit of output to do this, some recent cartridges are so high that some RIAA circuits will clip

 

[Craig B]

Certainly the Grado designs have very low generator inductance. Not sure about the Nagaoka.

Mechanical damping is likely a factor also, some carts have little, some much more and this will impact severity of the tip mass resonance.
In addition to the electrical resonance you have that caused by the tip mass against the vinyl compliance.

There is a German Audio magazine comparison review of three Nagaoka built Goldring 2000 series models, plus Nagaoka's own MP150 and MP300. They appear to have tested the 5 models for both internal impedance and inductance, with impedance varying between 810 to 902Ω and inductance between 613 to 710mH. I'm not sure how much experimentation they did with loading, however, they recommended 47kΩ/<150pF across the board.

http://www.nagaoka-deutschland.de/pdf/TESTBERICHT AUDIO.pdf​

 

[Tony L]

FWIW here’s my old Nagaoka MP-500 thread. I stand by my findings which if anything align more closely with the analysis on TNT. I can’t explain it technically, but I certainly don’t have any treble-spiking using what I suspect is quite a high capacitance phono stage.

 

[MusicMiles]

Over the years there have been lots of speakers made of alternative materials from concrete to plastic and metal. None of them have caught on.

It seems Magico and Wilson Benesch are doing ok with aluminum and carbon fiber.

 

[Tony L]

It seems Magico and Wilson Benesch are doing ok with aluminum and carbon fiber.

I’d cite the JR149s as a spectacular early example as they managed to produce a radical low-mass and non resonant cabinet design at a fairly budget price. They remain one of the best small speakers regardless of price to this day IMO. Stunning things, The cylindrical tube is just a bit of flat aluminium that’s been run through some metal rollers to form it, no vastly expensive moulds needed like Genlecs, Neumanns etc (Jim Rogers initially trained as a metalworker apparently).

 

[Yank]

Wash your mouth out

I do that every day, but considering how many other MM carts, better than Rega, manage to work with replaceable stylus assemblies, there's no excuse not to include the feature which would make ownership much more convenient.

 

[MusicMiles]

I’d cite the JR149s as a spectacular early example as they managed to produce a radical low-mass and non resonant cabinet design at a fairly budget price. They remain one of the best small speakers regardless of price to this day IMO. Stunning things, The cylindrical tube is just a bit of flat aluminium that’s been run through some metal rollers to form it, no vastly expensive moulds needed like Genlecs, Neumanns etc (Jim Rogers initially trained as a metalworker apparently).

A sentimental recollection from another Era I'd assume as I had to do a little research to get a brief background on the Rogers JR149. A novel design approach and apparently well regarded. History is full of alternate approaches to materials utilization and design.

 

[Craig B]

If we are going to have replaceable stylus assemblies, can we at least agree to go back to knob-less?

 

[Craig B]

Well, Rega's subtle clues and hints are all in and have been collated and analyzed. As such, I feel confident in suggesting that Rega's impending new phono cartridge will be an induced magnet design that logically employs an axially magnetized permanent ring magnet.

The Ortofon VMS is dead, long live the Rega <summat>.

 

[Fudgemaster]

Just hope it's affordable for those of us with limited resources.