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Low compliance MM or MC

Discussion in 'audio' started by Mark Packer, Mar 22, 2020.

  1. yeti42

    yeti42 pfm Member

    I Think micro cm/dynes is maybe what is meant.
    I used to run a DV17D2 or 3 for most of the time on my Rock, 15 micro dynes but so light it didn’t cause an issue and wouldn’t even on a Zeta. Have you found the vinyl engine resonance tool by the way?
    I recently got a hifi news and record review test disk in preparation for fitting an SPU Royal N to my Schröder, (13g eff mass with aluminium mount, 18 with brass) which I still haven’t got round to so no recommendation, but I ran my Proteus on the resonance tracks and was surprised to see it wobble at 7Hz, I thought the compliance was around 13 but that resonance only makes sense if that figure is quoted at 100Hz or the suspension has softened, which seems unlikely. I did find that using a lot of magnetic damping was required to get its considerable best out of it and here is my point. As far as I can remember, damping a resonance will change it’s amplitude but not its frequency but with a resonance on the limit it seem to help to have a bit. With the Townshend’s damping you may find you can push the limits a bit more than with most arms so anything from medium compliance up should be OK.
     
  2. stevec67

    stevec67 pfm Member

    Mantra Audio, UK. They have 1022 and 1042, the body is identical.
     
  3. PerF

    PerF Member

    Many thanks !
     
  4. Craig B

    Craig B Re:trophile

    If you are actually using the damping trough then phono cartridge compliance is a none issue.
     
  5. Rockmeister

    Rockmeister pfm Member

    do you have a link to a learned article on this? The silicon fluid provides more lateral damping than vertical...in which direction is a cartridge's compliance most effected? Not doubting you but just interested what figures you have.
     
  6. stevec67

    stevec67 pfm Member

    I haven't seen any figures but this would seem to make sense. AIUI the one channel goes up and down at 45 deg from vertical, the other channel at 45 deg the other way, so the 2 "phases" are 90 deg apart. The point of compliance matching is to avoid the tail wagging the dog in the case of a light arm and stiff cartridge, and if you have a damper on the moving end then the least compliant cartridge in the world will be forced to follow the groove.
     
  7. Craig B

    Craig B Re:trophile

    Good point. Perhaps 'should be' would have been a better qualifier.

    Another way of looking at this is from the perspective of the geometry of the source of energy which is to be controlled. If we consider how the tonearm is driven into resonance via two modulated plains that are at 45º to both horizontal and vertical, then neither vertical nor horizontal can be taking precedence over the other. IOWs, the business end of the tonearm is either well damped or it isn't. Clearly, in the case of Dinsdale's and Bugge's work at Cranfield, the damping must be highly effective compared to that which is applied at 1.45" from the tonearm pivot (i.e. SME and Mission 774).

    The only learned articles I have access to at the moment are SME's FD200 Fluid Damper instructions and the Elite Rock and Townsend Rock III manuals, neither of which make a distinction between lateral vs. vertical damping, only that there will be 'a substantial reduction in the Q of the low frequency resonance' (SME) vs. 'completely damps out arm/cartridge resonances and locks the pick-up arm to the base/plinth assembly and hence to the disc, at audio frequencies' (Townsend). I did have a copy of J. Dinsdale 'Precision Engineering Aspects of Record Player Design' someplace, from back when I had scholarly access to such things, but I've not come across it for some years now. I also have some early Rock reviews within some old magazines back at mine that I'll have a look though if/when the GF lets me out of lockdown.

    EDIT: Turns out I do have an old Dinsdale article from his Cranfield days in Windows/IE .webarchive format. Not something I can open on the Mac here (seen as 'code'), but I do still have a Windows laptop for work at home, so stay tuned.
     
    Rockmeister likes this.
  8. Mike Reed

    Mike Reed pfm Member

    As a highly satisfied Proteus owner, I'm not sure I follow the above; probably because I'm a bit thick or out of touch and don't have test discs which have resonance measurements (and they're old). I believe the Proteus and similarly other Transfig's to be happy on medium mass arms (say, 12 to 18g +/-).

    All I know is that my cart. consistently sounds fantastic with many hundreds of hours on the clock (on a 14g approx. 12" arm). Hence I don't understand your 'research' findings differing from my simple listening experience. Is there a possibility of something else not exactly synergistic, or am I totally misconstruing your post?
     
  9. stevec67

    stevec67 pfm Member

    Was that when they were being pursued by a giant hedgehog called Spiny Norman?
     
  10. Craig B

    Craig B Re:trophile

    Ah yes, the Piranha brothers, born, on probation, in this small house in Kipling Road, Southwark. :)
     
    stevec67 likes this.
  11. yeti42

    yeti42 pfm Member

    It certainly sounds fantastic even after 5 years of at least 500 hours per year use and probably double that some years. The arm was commissioned to carry a Proteus so should be a perfect match, and on paper it is, if the cartridge compliance is quoted at 10Hz. It was a very considerable improvement over an Aro but coincided with a new deck so probably not all down to the arm. The test record results only make sense if the compliance is quoted at 100Hz, it’s a fairly well regarded test record, except for the bias test tracks which are way out. I may get to the bottom of it one day.
    I want to examine the stylus under a microscope given the amount of use its had but the music it makes, makes it’s very hard to take it out of the system.
     
  12. Mike Reed

    Mike Reed pfm Member

    Thanks for that, Yeti. I am both amazed and pleased that your Proteus has 2500 hours approx. and still sounds good. I've got about 850 hours on mine for about 5 years. I've long had a feeling that the tip profile and stylus in general is way above average, as it rarely needs cleaning, even though my records are all RCM cleaned.

    likewise, I'm loth to take mine off the arm, even though I'd like to re-mount my K. Urushi Vermillion after 3 years in my drawer. The P is currently on a 12" PU7. I've tried it on my 12" Ace Anna unipivot, and it's different, but that was a long time ago. The K prefers the gimballed arm (understandably), and probably a heavier mass arm, which I had been thinking about (before the virus hit!)

    Which arm/deck/amplification/speakers are you using? Mine is a N.A. Dais, E.A.R. top pre. with 509 mono's feeding Quad 2905 ESLs.
     
  13. Mike Reed

    Mike Reed pfm Member

    Sorry, thought I'd quoted you for my comments above.
     
  14. yeti42

    yeti42 pfm Member

    Deck is an Artemis SA-1 with a Schröder Reference. The rest is all DRed Naim, Supercapped superline, 500 series into passive NBLs.
    The deck is a Frank Schröder design built by a firm in the States (since gone bust). My example was used by Frank Schröder for demonstration purposes and was sold with the offer to jump the waiting list for a Reference arm, which still took 4 month to build. The arm has a lot of fine adjustment, and needs it, but no verniers. Tuning it in takes some time, a good ear and a light touch with an allen key. There was a fairly steep learning curve which still has a little bit of a slope to it.

    I’ve had a SmartTractor on order for over a month now, waiting for that is my excuse for not changing out the Proteus as I’ve left my Feickert in France but with all this time on my hands I may not wait much longer.
     
  15. Mike Reed

    Mike Reed pfm Member

    Thanks for that. I've just looked up your arm, which is a bespoke item and I wonder which length and eff. mass you chose. I didn't see whether it's a unipivot or a gimballed arm though. As you've an Aro, I guess the latter. I set mine by my original Dr Feickert; the SmartTractor is nice (but pricey !) and apart from the mirror (handy!) I don't think there's much effective difference.

    The arm I had in mind to replace the 12" Ace Anna is the Reed 3P which weighs in at around 19g. Lovely looking thing with a good rep. (and local dealer friend) and of course it's my namesake !!!!! Thought of chopping out my Koetsu for a Miyajima but this pandemic has put a hold on everything, quite apart from stock market paper losses and an empty flat which is going nowhere anytime soon and costing.

    Have to ask; which combo do you prefer; the Aro/Proteus or the Schroder/Proteus, esp. if that latter is not a unipivot ?
     
  16. yeti42

    yeti42 pfm Member

    The Schröder hangs by a thread, with a very strong magnet pulling it down. I asked Frank Schröder to make me an arm to suit a Proteus and to put BNCs on the end of the cable but left the details up to him, the result claims an effective mass of 13g as supplied with an aluminium cartridge mounting plate and is around 10” long.The magnet gap is adjustable, as is just about everything else. The arm wand starts out as wood but is treated in some way to stabilise it. There is a choice of woods but it’s made for the desired effective mass, Schröder claims the choice doesn’t effect the sound once treated. It’s fussier to set up than an Aro but gets out of the way more once it is. Nothing like a gimballed arm.

    We were planning to move to France after I retire in the summer, at least before the end of the transition period. I’m pretty well done for upgrades now except maybe speakers once we’ve moved if the NBLs don’t suit the new room. The pandemic has made everything less certain, even survival.
     
  17. Mike Reed

    Mike Reed pfm Member

    Thanks for that; I hadn't read that bit, so very interesting; esp. the 13g as optimal for the Proteus. The Reed I have in mind (a unipivot) has a choice of wooden arms; an aspect I favour.
     
  18. yeti42

    yeti42 pfm Member

    If you have a friendly local dealer you’re well placed to try one out. It will be interesting to see how you get on with it, set up looks very flexible and precise.

    I came across this site while I was researching the SPU Royal N
    https://medialux.blog/author/querstrommotor/
    Mostly blogs about valves and cartridges, using Schröder arms.
    There’s a survey of some of the Koetsus in there somewhere, including the vermillion which should help you calibrate his findings.
     
  19. Mike Reed

    Mike Reed pfm Member

    Gosh but what a long and rambling account. From valves to cart's to speakers and back to valves etc. This was very interesting, Yeti, so many thanks. One thing occurred to me reading this (as he compares internal resistance) and that is that the Proteus' internal figure is one ohm ! Apart from Audio Note, unparalleled, I believe. It just so happens (without any scientific nous) that I believe this figure to be symptomatic of a great cart.

    It's made me want to try out my Vermillion again, but unfortunately, the Transfig. will have to come off !
     
  20. yeti42

    yeti42 pfm Member

    I’ve heard the io one on a WT Versalex (and a 400 Royal) and really enjoyed it (unlike the Benz LPS that preceded it), it did remind me a bit of the Proteus in its dynamics. Not really suitable for a superline however, it would need a 1:5 SUT to get the level up, not sure if that would even work (what would a SUT feeding a rather RF sensitive 64dB gain amp do for noise?) Rebuild costs on an io makes it almost tempting but I suspect it would end in a complete change of system and I’m not finished with the Naim yet.
    The Vermillion is a possibility but I’m trying to avoid high rebuild cost if I can.
    Anna Mighty Sound say they can rebuilt a Proteus with “original parts” for around 40% of what I paid for the cartridge so I will probably give then a go if they’re still in business when the time comes. I asked Goldring and they won’t do it, not sure about the Expert Stylus Company or Northwest Analog but the latter seem to fit a Gyger to everything judging from their web site.
     

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