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Thread: Sub - chassis isolation bobbins

  1. #41
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    If you are sure, John. Nice to hear of your measurements and use of Audacity. I have used it for many years, the filters are particularly useful.

    Quote Originally Posted by steve195527 View Post
    being able to reproduce it via speakers isn't necessary I was talking measurements, objective rather than subjective effects ,"below meaningful measurement" was what Linn used to claim.
    fair enough Steve, but that statement from Linn is loaded, it was Ivor's insistence that idler drive turntables, Garrard in particular, had a lot of rumble, whereas most of the problems were from turntable mounting, rather than the mechanicals themselves.

    by mass and damping I was meaning the way some methods are used to "control" vibrations, mass can be used but that usually just moves the frequencies that get excited. Damping is not uniform in the way it works, you can damp some frequencies but others will be relatively unaffected by the damping applied and some materials used as damping/vibration absorbance change with time, especially ones using rubber, even sorbothane stiffens/hardens with age
    agreed, mass doesn't (ever) damp, just change the resonance frequencies. And damping is not a constant across the audio frequency range. But good damping materials have, almost by definition, a general level of damping across a large range where it is effective, lower frequencies being controlled by stiffness, and midrange being controlled by mass, but all resonance amplitudes are controlled by damping.

    As for ageing, well, again, I agree, it's a fact of life, but applies to most materials. I still run a few turntables which have their original rubber tyres, idlers, platter mats, grommets and damping, although this week I had to replace the rubber seals on three jars of pickles!
    cheers.....Bryan

    http://qualia.webs.com/

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    You can measure stuff to the nth degree. What about enjoying the music and accepting nothing will ever be perfect?

  3. #43

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    Quote Originally Posted by cat's squirrel View Post
    If you are sure, John. Nice to hear of your measurements and use of Audacity. I have used it for many years, the filters are particularly useful.



    fair enough Steve, but that statement from Linn is loaded, it was Ivor's insistence that idler drive turntables, Garrard in particular, had a lot of rumble, whereas most of the problems were from turntable mounting, rather than the mechanicals themselves.



    agreed, mass doesn't (ever) damp, just change the resonance frequencies. And damping is not a constant across the audio frequency range. But good damping materials have, almost by definition, a general level of damping across a large range where it is effective, lower frequencies being controlled by stiffness, and midrange being controlled by mass, but all resonance amplitudes are controlled by damping.

    As for ageing, well, again, I agree, it's a fact of life, but applies to most materials. I still run a few turntables which have their original rubber tyres, idlers, platter mats, grommets and damping, although this week I had to replace the rubber seals on three jars of pickles!
    what really makes me smile is the way things go in circles, we were forever taking 301's 401's and even the odd td124 in part ex against more modern DD and belt drive turntables,now it seems folk are trying to replace modern(ish) belt and DD turntables with the ones folk couldn't wait to get rid of,as for Ivor,isn't everything he says weighted to favour what his company makes and sells?(understandable in a way!)
    we always found most of the issues with 401's was to do with the motor mounts needing sorting out,they could be as quiet as almost anything with a bit of tlc
    Dom at northwest analogue loves them and he thinks, against current trends, that the 401 is better than the 301!
    Last edited by steve195527; 5th December 2016 at 23:28.

  4. #44

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    Quote Originally Posted by TIU View Post
    You can measure stuff to the nth degree. What about enjoying the music and accepting nothing will ever be perfect?
    I totally agree but was only stating what Ivor claimed about noise produced by the LP12,which in reviews where it was actually subjected to testing did bear this out

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    If I was to change my tt type, I'd go for a DD rather than a belt drive.

  6. #46

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    Quote Originally Posted by TIU View Post
    If I was to change my tt type, I'd go for a DD rather than a belt drive.
    if I was buying one nowadays I would prob buy one of the 2nd hand sp10 mk2's off ebay,my speakers are in completely different room to rest of system so feedback shouldn't be an issue,there are a couple on ebay now for under Ģ2000

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    You can measure stuff to the nth degree. What about enjoying the music and accepting nothing will ever be perfect?
    If I was to change my tt type, I'd go for a DD rather than a belt drive.
    somehow, these two statements seem to go together! (only joking, or am I?)
    cheers.....Bryan

    http://qualia.webs.com/

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    Quote Originally Posted by TIU View Post
    If I was to change my tt type, I'd go for a DD rather than a belt drive.
    You'd be surprised how good belters can be Gary, though I'm talking three motor Voyd here. Yes the motors can be heard when starting up close to the deck ,or when changing records on the fly but whoa the performance is something else! Pure subtlety when needed and dynamics to die for! Truly awesome device.

    Trouble is they are huge, rare and costly, spares can also be difficult, but mine is reliable and it stays in tune - they bounce with utter precision and the means of isolation is truly on the button. A Linn would never get there!

    It also makes me laugh when Linnes talk about spring compression on the rear arm side of an LP12 chassis, have you seen the size of LP12 springs? With the Voyd the three tension springs are approximately twice the diameter of a Biro spring with a wire diameter not much thicker and it takes SME V's with ease! Guy Adams, Guy Sergeant with collaboration from Les W (and of course Philip Voyd) :roll eyes certainly knew what belter performance could result in when designed properly. But the top end Reference model was nearly Ģ7k toward the end of production. Mine is merely an entry level three motor Voyd, but I love it.

    Oh remember when Linn (and some others) said an SME IV or V arm is too heavy for the LP12 well that too was BULLSHIT! The latest Ekos SE is heavier than the SME V!

    I also have an original SL120 Technics that I have experimented with. I've filled the top ally plinth with epoxy resin loaded with glass beads & lead shot and also Kingspan foam. The original plastic base is loaded with epoxy resin, plywood , glass beads and lead shot. The original feet are not used, I use three Sorbothane hemispheres directly mounted to the base. For what it cost me it's a superb performer

  9. #49

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    Quote Originally Posted by John R View Post
    You'd be surprised how good belters can be Gary, though I'm talking three motor Voyd here. Yes the motors can be heard when starting up close to the deck ,or when changing records on the fly but whoa the performance is something else! Pure subtlety when needed and dynamics to die for! Truly awesome device.

    Trouble is they are huge, rare and costly, spares can also be difficult, but mine is reliable and it stays in tune - they bounce with utter precision and the means of isolation is truly on the button. A Linn would never get there!

    It also makes me laugh when Linnes talk about spring compression on the rear arm side of an LP12 chassis, have you seen the size of LP12 springs? With the Voyd the three tension springs are approximately twice the diameter of a Biro spring with a wire diameter not much thicker and it takes SME V's with ease! Guy Adams, Guy Sergeant with collaboration from Les W (and of course Philip Voyd) :roll eyes certainly knew what belter performance could result in when designed properly. But the top end Reference model was nearly Ģ7k toward the end of production. Mine is merely an entry level three motor Voyd, but I love it.

    Oh remember when Linn (and some others) said an SME IV or V arm is too heavy for the LP12 well that too was BULLSHIT! The latest Ekos SE is heavier than the SME V!

    I also have an original SL120 Technics that I have experimented with. I've filled the top ally plinth with epoxy resin loaded with glass beads & lead shot and also Kingspan foam. The original plastic base is loaded with epoxy resin, plywood , glass beads and lead shot. The original feet are not used, I use three Sorbothane hemispheres directly mounted to the base. For what it cost me it's a superb performer
    Some of the stuff repeated about the lp12 is bull,some of it perpetrated by linn and their dealers in the hope of steering punters towards an all linn front end ie only linn arms can bring out the best in a lp12 and vice-versa, linn cartridges bring out the best in their arms and turntable,improving your turntable(ie buying a lp12!) is by far the most important thing in improving your system,how folk fall for it is beyond me
    I am pretty sure that when linn started selling cartridges they had them voiced to suit their isobarik speakers,because they only ever sounded reasonable with a linn cart feeding them

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    Itīs true John The latest Ekos SE is heavier than the Sme V and the most of that Linn says about this itīs not true, but as always they have some thing that is worse that in the competition to something else they claim that is doesnīt work on a Twelve.
    I have now built my third Lp 12 with Sme V and they sounds fantastic. In the latest one i have the Sme V ( D ) detachable headshell , than you also can set the azimuth witch is a plus on a Lp 12.
    Funny that they have a Kore for Sme and they dont work ??

    /L
    Tangerine Audio Stiletto, Plateau, Skorpion, SME V ( D ), Dynavector DRT XV 1S, Linn Cirkus, Linn Radikal Klimax.
    https://www.linnarts.se

  11. #51

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    Linn used to claim the LP12 would sound better than any other turntable in A/B demos using any arm,are they now saying only works properly with certain arms,possibly folk trying to use the Dynavector on them changed the "any arm" claim:-that one was/is a bit on the heavy side for the LP12

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    John,
    With all the talk about motor vibration,I have been trying different gaskets with the Mober DC motor and I would like to give your plattamat2 ago.So could I get some from so I can make a motor gasket.
    I have been using a gasket made of sorbothane. I like plattamat2 record mat I'd like try it for motor gasket I bet it's better than sorbothane.
    Last edited by rkay5; 18th December 2016 at 23:44.
    Robert
    SE LP12/Sole SubChassisVIII/SSP12/Hercules-Mober DC&PSU/Roksan NimaUnipivot+sKale/ZYX R50 Bloom L/Whest PS30R /CambridgeAudio Azur 851A/MerlinTSM/Mytek St192DACTascamDA-3000

  13. #53
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    I'll have a look for some off-cuts for you Robert, 4" x 4" should do it yeah?

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    Couple questions...

    1. I long ago read that direct drives, relative to belt drives, deliver a vibration right to the platter (presumably idlers too?), and while that vibration itself is below audible frequencies, the sub audible shake-rattle-roll of it compromises the cartridges ability to capture fine details (because the record is made so much more of a moving target).

    2. Was motor noise a factor in the design of your inSole bobbins, John, or is it just one more source of vibation they eat up to keep the platter moving in only one plane?

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    It appears to be a misconception that idlers input rumble into the transcription of signal from the drive motor and bearing of these TT's.. When things are bad I am sure they do,but when components are in good order I certainly do not find this to be the case with my Lenco 75. In fact my Lenco 75 is pretty much silent. Its drive system is one of the best designed in my opinion, it does not impart side thrust on the platter and its idler wheel contact patch is tiny. The secret of the Lenco is its wedging effect between the motor spindle and platter underside, the consequential effect on then torque given by this design is a very powerful and dynamic presentation not unlike a three motor Voyd TT. However, getting the drive spot on with a Lenco takes patience

    All sources of potential vibration are considered with the "In Soles" Tubey, but mostly that of feedback from the listening environment itself, springs will vibrate from room excitation (airborne vibration) structures will vibrate too as a result, harmonics will be a consequence of vibration so in a TT it's best to eliminate the source - the springs themselves.

    The room is the most important factor in achieving top performance from your system including the TT itself. In Soles also prevent the sub-chassis from moving around within the plinth and we find this significantly reduces instability in extended notes especially that of piano.

    The best measuring devices in determining if any modification is successful is ones own ears. In Soles told me in no uncertain terms that in my system/room they beat the springs significantly.

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    Quote Originally Posted by Tube Nube View Post
    Couple questions...

    1. I long ago read that direct drives, relative to belt drives, deliver a vibration right to the platter (presumably idlers too?), and while that vibration itself is below audible frequencies, the sub audible shake-rattle-roll of it compromises the cartridges ability to capture fine details (because the record is made so much more of a moving target).

    2. Was motor noise a factor in the design of your inSole bobbins, John, or is it just one more source of vibation they eat up to keep the platter moving in only one plane?
    Surely reproducing 'fine detail' (whatever that is) is dependent on cart, tonearm, phono stage, amp, speakers, the whole chain.

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    Quote Originally Posted by TIU View Post
    Surely reproducing 'fine detail' (whatever that is) is dependent on cart, tonearm, phono stage, amp, speakers, the whole chain.
    Agreed. But let me re phrase it " fine detail " as any detail or information will be more challenging to retrieve when a jack hammer is applied to the platter, versus better isolated from it. Bit of an exaggeration--I just like the visual of it.

    John, thanks for the tutorial on idlers! More to these than I reckoned -- goes to Tiu's point about the whole package.
    Last edited by Tube Nube; 10th December 2016 at 20:59.
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    There has been no real developments in record playback since the main drive types were established. Many people have returned to the idler drive system, now recognising its advantages. I have had belt drive turntables and direct drives, in particular the highly regarded Sony PS-6750. I don't agree with the premise that the idler drive system has the inherrent faults mentioned. As John said, it depends on the implementation.

  19. #59

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    what is td124 classed as?belt?idler? or belt/idler? with that model the motor is isolated from the idler wheel by a belt so in theory it incorporates the best of both types,as long as things aren't worn then it will incorporate the worst of both types!

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    But the TD124 has superb engineering build on its side Steve, it's a class act.

    My assumption is parts will last a very long time before they wear out, but when they do it'll let you know in no uncertain terms
    Last edited by John R; 11th December 2016 at 12:02. Reason: Punctuation.

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