Ah, quartz is inorganic. It is silicon.
Organic would be carbon containing.
Organic would be carbon containing.
Vintage DD turntables. Are we living dangerously?
I have just acquired a 32 year old JVC/Victor TT-101 DD turntable after having its lesser brother, the TT-81 for the last year.
TT-101
This is one of the great DD designs made at a time when the giant Japanese electronics companies like Technics, Denon, JVC/Victor and Pioneer could pour millions of dollars into 'flagship' models to 'enhance' their lower range models which often sold in the millions.
Because of their complexity however.......if they malfunction.....parts are 'unobtanium'....and they often cannot be repaired.
TT-101
This is one of the great DD designs made at a time when the giant Japanese electronics companies like Technics, Denon, JVC/Victor and Pioneer could pour millions of dollars into 'flagship' models to 'enhance' their lower range models which often sold in the millions.
Because of their complexity however.......if they malfunction.....parts are 'unobtanium'....and they often cannot be repaired.
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Hi lewm, thankyou for your informative post, I enjoy learning, we did listen to a whole lot of equipment to come to our impression's, our goal was to go back in time to hear if anything was as good as today or better, we got frustrated with the notion that newer was better, we'll, the consensuous was wrong!, I suppose that getting jensen or murdof capacitors is inadequate for none signal capacitors for the technics sl 1600mk2 turntable we hand picked out, I would enjoy all the help from you and anyone else, as far as the main system you asked about, it is the only modified krell 700cx out there according to krell that we spent the $11,500.00 doing so back in December 2014, then I'm useing a digital player that we got rid of an ayon cd2s player for called, Vincent cds7 , btw, we run directly to the Krell 700cx amplifier, then, we have taralab's zero gold XLR interconnect between them, speaker cable's are taralab's omega gold speaker cable's, with special order omega 10" speaker jumper's for bi-cableing the 4 speaker post on our jbl L7 vintage speaker's, btw, just bought the mint second pair after selling the first L7 speaker's thinking we would go up to any $25,000.00 new or used speaker's, that expenditure was a bummer, so we looked long and hard and found mint condition jbl l7 speaker's, paid $ 400.00 shipping out of new York city to Mobile, Alabama, useing plycon furniture and automobile transportation group carrier, I also use a taralab's oyaida terminationed Cobalt power cord, with furutech gtx-rhodium NCF outlet's through out the system with dedicated lines we did our self's, so the main answer to your question about the analog turntable, we do not use or have a active pre-amp on main system,cheers. |
So Harry is making his VPI Direct even better... https://www.audionirvana.org/forum/the-audio-vault/analog-playback/turntables/10314-peek-at-vpi-aven... And in the latest TAS, JV talks to Gunther Frohnhoefer of Acoustic Signature on his latest Invictus belt-drive and asks him about the "comeback" of Direct Drive... Yes, I know there has been a little comeback of direct-drive motors. Invictus is a cost-no-object product. If we had thought a direct drive motor was significantly better, we would certainly have made an investment to design it. Yes, you can get better wow/flutter values with a direct-drive motor of high torque. This is the truth and nobody can deny it. Not even me. But at what price? Sounds a little defensive to me.....😎 |
Halcro You have edited out the most significant comment by Gunther Frohnhoefer of Acoustic Signature with regard to wow and flutter But, yes, the direct-drive motor will still produce better wow/flutter values because we use belts, and belts are worse in wow and flutter than a direct-coupled motor.It appears that they use stretchy belts. I suspect they have focussed on lowest noise and the stretch belts are a bandaid. As an aside he claims the 6 AC motors get the 32kg platter on the Invictus up to speed in under 10 seconds. My Final Audio VTT1 which uses one large AC motor can get its 26kg platter up to speed in less than 1 revolution ( 1.8seconds ). So I can only conclude that the Invictus uses weaselly motors and stretchy belts. I also owned a Platine Verdier - weaselly motor and stretchy belt - the replacement of the Verdier drive system with that from the Final demonstrated clearly that low power motors are a source of instability even when using high inertia high mass platters. For best speed stability in belt drives you must have high inertia, high torque stable drive system and non stretchy belt such as silk or kevlar. I also note that he comments that compared with Direct Drive motors he can get high quality AC motors at lower cost. He seems oblivious to the possibility of using AC motors in DD's or Induction motors for that matter. Overall I am not impressed and sceptical about a TT, the Invictus, that has no published specifications on performance nor any technological information available. Furthermore their Tiderfolon bearing is simply an self lubricating material - it is not possible for it to be frictionless as claimed on their website. I use a custom self lubricating polymer bearing in my 1960 Pioneer broadcast idler drive TT ( that blew away the Platine Verdier in speed stability ), its not that radical. |
Halcro Dover, Unless I was prepared to type out the whole two page interview here...I was bound to leave out many things he said. I think it's debatable what the "most significant comment" may be..? |
Halcro - yes I agree, Acoustic Plan's view on the importance of wow and flutter is a cop out, particularly for a statement product with a price tag to match. Any improvement in wow and flutter must improve the enjoyment of music per se - musical timing is fundamental. They should shed some of the bling and provide a better drive system. Unfortunately I suspect market demand for bling over substance is a driver these days. Go at stand at an audio show and see how many folk make value statements on performance based solely on looks. |
Hi Halcro, On another thread you indicated that you've transitioned from a metal skeleton metal frame plinth to a solid Granite plinth for your TT-101. From the picture, I didn't see holes in the circular Granite to accomadate hardware for securing the TT-101. Is the TT-101 resting on the Granite without being fasten to the Granite? Would you please describe what are the sonic differences? Thank you Norm |
Hi Norm, When I first set up my Victor and armpods, I supported the turntable motor with its own metal shroud on Tiptoes http://i.imgur.com/Xp97BF8.jpg This at first sounded better than most tables I had previously heard but I thought I could do better than this makeshift arrangement. So I designed and had built, a stainless steel cradle http://i.imgur.com/UuEyECm.jpg which had adjustable spike supports and three rubber supporting pads on top to rest the motor assembly http://i.imgur.com/2FH8xGR.jpg This was indeed an improvement in rigidity over the previous model, however after a few years, I discovered that the lightweight nature of this supporting structure allowed for accidental movement of the geometrical relationships vis-a-vis the massive 24lb armpods. So I designed a circular ’plinth’ cut from a single solid block of granite and polished http://i.imgur.com/ouvBGRN.png I lined the inner surface with cork to absorb the electro-magnetic waves bouncing around from the transformer, power supply and motor unit and had the same three rubber ’button’ supports fixed to the top to support the motor unit itself http://i.imgur.com/h673918.jpg The improvement in sound was revelatory and confirmed the fact that Newton’s third law of motion (For every action there is an equal and opposite reaction) applied to the motion of turntables. The centrifugal force of a spinning platter must be resisted by enough ’mass’ to avoid movement. http://i.imgur.com/ddKNHVx.jpg This is more readily seen in a suspended turntable where the centrifugal force is not resisted and must create movement about the sprung suspension. The Kronos turntable with its two counter rotating platters effectively solves this problem for suspended turntables. http://media.tas.zeitpress.com/articles/images/JH%2011%20The%20Kronos%20Sparta%20turntable%20comes%2... With an unsuspended mass-loaded turntable of any kind, that centrifugal force is absorbed and thus resisted by the mass of the supporting structure. The sonic effects of this added mass to the TT-101 in my situation, is a tightening of the presentation together with a relaxed delineation of the entire soundstage and instrumental focus. The detailing snaps sharply and the lower registers plunge solidly with an unwavering pitch and tunefulness. And as a bonus.....the geometrical relationships to the solid bronze armpods remain static 😘 Regards |
Hi Halcro, **The centrifugal force of a spinning platter must be resisted by enough ’mass’ to avoid movement.** Interesting point. Assuming the motor is still coupled with three rubber pads, it's not only the mass of the pod which resists motion, it's also the integrity of the coupling and mass of the motor unit insuring that resistance. I wonder if performance would improve if the motor unit was bolted onto the pod. Regards, |
"With an unsuspended mass-loaded turntable of any kind, that centrifugal force is absorbed and thus resisted by the mass of the supporting structure." I don't want to say "I told you so", but I did tell you so back when that was a point of contention among us. Back when Raul was recommending just sitting the naked chassis on a set of AT pucks that were said to have magic powers. And let me apologize in advance for being pedantic, but this is not a "centrifugal" force at all. This is a force that is described in Newton's Third Law of Motion: "for every action, there is an equal and opposite reaction". Thus it is a force vector that has a direction described by an arc opposite to the direction of the arc of turntable rotation. This is why and how the Kronos works; the lower platter, of mass equal to the working platter, is rotating opposite to the direction of the working platter. and this effectively cancels the forces. Otherwise, the tail wags the dog. And finally, to be even more annoying, there is no such thing as a "centrifugal" force. The force described in that commonly used misnomer is actually centripetal; to keep the object from flying off in a straight line, a force directed toward (not away from or "centrifugal") the center of rotation is generated and required. |
**Thus it is a force vector that has a direction described by an arc opposite to the direction of the arc of turntable rotation.** What force vector is that? If the platter/motor moves it would be in the direction of rotation. There is no force vector opposite to direction of rotation. It's the motor unit coupling to the mass of the pod that resists movement. The mass of the motor is heavy enough to resist, otherwise Raul wouldn't have been able to listen to the table. Regards, |
lewm Lewm, You are wrong when you say there is no such thing as centrifugal force. Centripetal force is that at a right angle directed toward the centre of the axis of rotation. Centrifugal force is the apparent force, equal and opposite to the centripetal force, drawing a rotating body away from the center of rotation, caused by the inertia of the body. Centrifugal and centripetal are opposite sides of the same coin. If you look at the platter from the outside you see centripetal force, if you sit on the platter you feel centrifugal force - get it. Newton’s First Law states that “A body at rest will remain at rest, and a body in motion will remain in motion unless it is acted upon by an external force.” If a massive body is moving through space in a straight line, its inertia will cause it to continue in a straight line unless an outside force causes it to speed up, slow down or change direction. In order for it to follow a circular path without changing speed, a continuous centripetal force must be continuously applied at a right angle to its path. |
fleib Fleib, You don’t seem to understand how a direct drive TT works. Half the motor is coupled to the platter, the other half of the motor is connected to the plinth. If you hold the TT upside down by the platter, then the plinth will spin. The mass of the relative mass of the plinth to the platter is relevant and the rigidity of the coupling of the half of the motor connected to ground affects speed and articulation. Clearly Raul is unable to here the effects of a rigid plinth and motor coupling in his system. |
Hi Fleib, Interesting point. Assuming the motor is still coupled with three rubber pads, it's not only the mass of the pod which resists motion, it's also the integrity of the coupling and mass of the motor unit insuring that resistance. I wonder if performance would improve if the motor unit was bolted onto the pod. The TT-101 merely resting on the three rubber pads is relying on the 'friction' of the motor-unit mass to transfer this motion energy into the granite plinth. I believe it's enough but you're right.....it would be better to mechanically connect it but at this stage, I don't know how? 🤔 Regards |
Dover, Modern physics says centrifugal force is a misnomer. It's called The Victor motor units are relatively heavy containing the transformer and all the electronics. One can spin the platter under power and it doesn't go anywhere. I haven't listened to the table (TT81) under these conditions. Regards, |
Halcro, I wonder if you would hear a difference if the motor unit was bolted on. I'm sure you're aware of the three bolt holes underneath the edge of the platter. This is how the motors were bolted to the CL-P2D plinth. It might be better with the rubber acting as a damper. Of course you could always use rubber washers in-between. If the washers were compressed there should be no movement? With a wooden plinth it's easy to install threaded inserts, but with a stone pod you'd probably have to drill a big enough hole and fill around the insert with epoxy? Regards, |
Hi Halcro, I should begin by saying, “nice job on the granite plinth”, which I neglected to mention on my earlier post. The black granite matches the armpods beautifully. Thank you for the in-depth explanation to my inquiries. The reason for my curiosity is because I’ve recently joined an exclusive” Are we living dangerously?” club. My JVC/Victor TT-101 was sold to me with a CL-P2 plinth and acrylic dust cover. The Victor CL-P2 plinth is made from particle board with a veneer clad, faux Rosewood, as with most plinths made from this era. The plinth itself is quite heavy and comes with four large plastic footers. The TT motor is evenly secured with hardware to the wood plinth. I’m looking for ways to improve on this plinth; whether it is a custom plinth as you have done or tweak the existing CL-P2. An Elgar 6000A line conditioner is used to feed 100VAC to the TT-101. I’ve dialed down the Elgar to the lowest possible voltage of 105VAC to best meet TT-101 requirements. I need to shuffle my equipment around to accommodate the TT-101 before spinning any vinyl on this TT. Since my inquiry on how your custom granite plinth is coupled to the TT-101 motor, several posters have commented to your approach. To me, it seems intuitive to mechanically fasten the motor to the plinth for best sonic results. What was the rationale to have the motor “sit” on the rubber points rather than have it bolted in place? I noticed the metal skeleton plinth also used rubber supports. Did you experiment both ways before concluding that this was sonically the best approach? It seems intrinsic that the plinth material selected has a lesser degree of importance when the motor just “sit” on the plinth as opposed to mechanically coupling the motor to the plinth. Furthermore, is it possible the granite plinth sounds better than the open metal skeleton design because the granite design encases the TT and is able to shield air borne vibrations reaching the motor? Regards, Norm |
halcro🤔 Pretty much as fleib mentioned, the way to go and its not that difficult would be to start by getting 3 threaded inserts, 1 diamond bit [hollow core] that is slightly larger than the insert od drill at low speed with water lubrication. Partially fill the hole with an epoxy, tape over the bottom of the insert to prevent epoxy filling the insert. Place the 3 fasteners in the rim of of the TT, lower the table and start the fasteners into the threaded inserts while the epoxy is still setting up there by centering the inserts to the fasteners. Use a slow setting epoxy to give yourself more time, and have an extra set of hands, one to lower the TT into position but not all the way down, and another to start the aligning threading operation. |
Fleib, Centripetal comes from the latin words "centrum" - centre and "petere" which means to seek. I can assure you that when using centrifuges the contents do indeed fly away from the centre, not towards. If you have any doubt, at the next carnival you can attend, take a ride on a horizontal spinning wheel and leave your seatbelt off. Then you can report back to us whether you flew back towards the centre or indeed away from the centre. |
Dover, Although I don't attend carnivals I have no argument with that. The question here is, does the rotation of the platter have enough force to overcome the mass coupling of the motor unit? Evidence suggests, the weight of the motor unit is enough to resist movement depending on the coupling to the pod, but is there micro movement which might not be readily obvious? That brings up another question. If the motor unit is bolted to the pod, would it be better to damp the coupling with rubber washers? A compressed thin rubber washer might not allow movement and provide a degree of damping which Halcro now has? Regards, |
Welcome to the TT-101 club Norm 👏 It seems to be growing at a great rate.... What table did you have before? I've listened extensively to a TT-71 mounted in a JVC wood plinth and whilst sounding good, it does not quite have the solidity of focus nor the reach into the lower sonic regions that the heavy granite plinth endows. The crystalline shimmers of the upper frequency harmonics are also clearer and more delicate with the granite. And Fleib is right.....the rubber dampening between the aluminium motor unit and the granite base is essential, as listening with the motor unit in direct contact with the granite was a drain on the emotional content. Direct contact to wood is a different kettle of fish...🐠🐟 I think you're correct in the assumption that with the rubber supports, the actual 'material' of the base assumes lesser importance than its 'mass'. And that was the motivating force in directing my design to 'stone'. Other than brass, bronze or steel....stone was the densest material for that form of plinth. I don't however agree with your thoughts on air-borne vibrations affecting the motor unit. What tonearm are you intending to use with your turntable?...or did it come with one already mounted? And have you checked that all the functions work correctly on the notoriously complex TT-101? Regards |
Hi Halco, My primary TT is the Scheu Premier with Verus Rim Drive and Talea II tonearm sitting on a Minus K. I also have a Technics SP-10 Mk2a in a DIY plinth and EPA-100 arm. I will audition the TT-101 with a SAEC WE-506-30 arm. Eventually, all three tonearms will be heard with the TT-101. My end goal is to have multiple tonearms on one TT. I have put the JVC TT-101 through its paces and verified everything works as it should. The KAB Speedstrobe confirms its speed stability as well. Thanks for sharing your thoughts on the JVC wood plinth and its short comings. You will agree I have a tedious task ahead of me to determine if the TT-101 truly merits a place on the Minus K. |
To all Victor TT-101 owners: I’m hearing a “hum” when I press my ear up to the platter mat. Sounds like a transformer hum. Doubt very much this is normal. Would other JVC DD table owners please chime in and comment on this? All the electronics are original. Will replacing the caps in the PS board eliminate this hum? Or is it something more seriously wrong? Like a bad/noisy transformer? The wall voltage measures between 102-103VAC. Plans to replace all the electrolytic caps are in the works. I’ve also noticed on several occasions the speed briefly jumps from “33.33” to “33.32 or 33.34” during lp playing. Is this normal? Playing one side of an lp, this may occur once or twice, or no at all. Halcro, is this what you mean by “Are we living Dangerously”? |
Halcro, is this what you mean by “Are we living Dangerously”? Kinda....😩 The TT-101 is just more complex electronically than any other deck I know of. I've never heard a 'hum' with mine however. Apart from replacing the electrolytic capacitors....the most critical thing I found with my TT-101 are all the 35 year-old solder joints. There can be micro cracks which are invisible to the naked eye. The best 'fix' is to flush them all out and re-do the lot. The most critical ones (especially if the speed indicator changes) are the joints under the control panel. I would strongly recommend that you send your deck to jpjones (if he is willing) who is somewhat of a 'guru' electronically and was able to fix Lewm's intransigent Victor where others had failed. Once fixed....I believe you can look forward to years of NOT living dangerously..👀 Good luck... |
Lucky enough to procure not one but TWO Denon DN 308 Direct Drive tables from Mexico. Now there is a DD table, had one some years ago which I restored, its now spinning Records at kftool s place on the east coast. These two will be "GrooveMastered" too, somewhat of a challenge as the motor is the size of a gallon paint can but I'm sure I can figure out something aesthetically pleasing. Good Listening Peter http://pbnaudio.com/audio-components/audio-turntables/groovemaster/groovemaster-vintage-direct |
Norm, A few questions: When you press your ear to the platter mat, I presume that the platter is not rotating. Correct? (It would be quite a trick to put your ear down on the mat with the platter up to speed.) The hum: is it a constant or intermittent? You say the "wall voltage" measures 102-103 VAC. I presume you mean this is at the output side of a 120 to 100V step-down transformer, if you live in the US or any other country with 120V standard. If not, what? And in connection with the last question, are you sure your TT101 is set up to receive 100V? Most are, but at least a few (mine included) were sold with selectable taps on the power transformer primary such that one can feed the motor with 240, 120, or 100V. Check that the wall voltage and the transformer voltages are copacetic. |
Hi Lewm, Yes, the platter is stationary where the constant hum is travelled up to the platter mat. I'm in Canada where 117v is standard. I'm using an Elgar 600A power conditioner adjusted to the unit's minimal output voltage setting of 103VAC. There is a diagram on the TT-101 transformer depicting 100vac as primary and 2 x 16.5vac / 1.2a, and 10.0vac / 1.0a as secondaries. I've replaced all the capacitors (8 in total) on the PS board in hopes of curing the hum. No luck. However, the speed fluctuation that I was experiencing earlier seem to have disappeared with the new caps. Following other TOTL DD designs, I've decided to move the xfmr into an external chassis. I'll post my results when this is done. |
I'll leave this to JP or someone else with more expertise, but I have to wonder whether using a power conditioner and not per se a step-down transformer could have anything to do with causing the hum that you perceive. Obviously, yours is a standard 100V unit. In the longer term, you would want to replace ALL the other electrolytics, as well as those on the Power Supply board. |
norm, Are you certain the Elgar unit is working correctly? I see that it's advertised as having sine output. I'd try a simple step-down as a sanity-check, à la https://amzn.com/B000WMK6QY. According to the literature the transformer in the 101 is a potted toroid. If that's vibrating, something is VERY wrong. JP |
Tried a new step-down transformer. It is now 98% hum free. A BIG improvement over the Elgar. Which confirms I have a broken Elgar. With ear pressed against the platter mat, I am still able to detect a difference between on/off. Would other TT-101 owners check this with their units if they can detect any difference between on and off? Thank you. |
I have not had the time to complete the TT-101, its rebuilt but have a counter problem that with the help of JP we might just have solved just last week. Other than focusing on production of all the other fun Audio Equipment we make I just last week got delivery of my Denon DN308-F broadcast tables (2 of them) that I'm going to spend some time on too. Thinking a large Slate plinth 4 - 5" thick on a solid aluminum platform possibly with some Still Point or similar isolation between the two, or a Minus K platform ? with the aluminum stand housing the electronics and possibly one of our PXi phono preamps as well. Suggestions from everyone greatly welcomed, if you were to own a no compromise DD table what would you like to see on it ? Ill let you know as soon as I have it (TT101) done - with the counter problem hopefully solved it'll be sooner rather than later. Good Listening Peter |
For the most part belt drives are simpler, so I guess all of us spinning DD could be considered to be living on the edge. Complexity does come with its share of bugaboos. Started my journey with an idler driven Dual back in 76 I believe. Then thinking like a lemming I jumped on the DD band wagon in 78 and a plethora of cheap tables followed in an attempt to get my lost music back. Fast forward to the early 90s when I picked up an AR XA at a garage sale for the grand total of $15. Contacted AR, they still had replacement belts so I ordered two. Purchased a Grado Platinum, modified the headshell to accept a top mount cart and my music was back. Later putting together a bedroom system I found mysdlf needing a table again. Purchased a Thorens TD166MKII, installed a Pickering XV15 1200E / D1200 cartridge stylus combo and thought I was set. I’m not sure what happened to find me looking for another table, but for some odd reason I decided to give DD another go. Purchased the big Kenny, installed the Grado Platinum and was blown away by how much improvement I was hearing over both my other tables, both belt drives. This lead me to my next Kenny table, the KD770D, and what a table it is. Currently running a Clearaudio Concept V2, nice quality cart I could live with, but it’s obvious the table cries out for more. So, are we living on the edge with our vintage DD tables? I say, "who gives a flying ......" when they sound this good for just a song and a dance. |
There has been quite a few posts in this thread about platter mats, especially for DD turntables. For my SP10mk3 (Krebs 2 mod), I have tried
Boston Mat 1, Micro Seiki CU180 and the TTM Mat with Matching Oil filled clamp (http://www.usaudiomart.com/details/649203862-ttm-mat-2-and-oil-damped-stabilizerweight-combo/). Amongst these 3, the TTM was the best and after I introduced it to Albert Porter, he too thinks it's the best for the Sp10mk3. However, I have found an even better platter mat taht I would like to share with the group. It's Acoustical Systems SDP (http://www.arche-headshell.de/accessoires/sdp-the-sonically-most-effective-upgrade-for-every-turntable/). SDP stands for Special Decoupled Platter. This is not just a mat but an additional platter that decouples and isolates the bearing and spindle from the stylus. While most mats offer some isolationa dn decoupling of the platter, this is the only mat I know that also decouples the spindle. It stands head and shoulders above all the other mats. In fact, for me, the improvement it brought to my SP10Mk3 was greater than the Kreb mods. It's expensive and requires the arm-boards to be raised but it's worth the trouble IMHO. Especially for DD turntables where you have the motor directly connected to the spindle (in most designs though there a few that are decoupled), it makes sense to decouple not only the platter but the spindle from the LP. Hence, SDP probably makes more improvements for DD turntables than Belt drive truntables. FWIW. |
Actually, I don't see this as off-topic. There have been many posts on this thread about mats related to DD turntables.
It's all about wringing the best out of vintage DDs. And I happen to think that the SDP is perfect for DDs and may help to resolve one remaining disadvantage of DDs over belt drives i.e. motor vibrations going up the spindle. That said, I'll be happy to answer any questions you have on the SDP. |
Phew! I'm so glad I moved my SDP platter post to a new discussion. That started a whole new discussion and can of worms. @theophile is correct and I stand corrected. Back to vintage DDs. Anyone tried putting EMI/RFI shield on the platters? I refer to this link for L-O7D: http://www.l-07d.com/tweaks.htm In the link, they use thin mu-metal shield for EMI and ERS paper for RFI shielding. |
