I responded to K's post over on his own thread. Suffice to say I too am very grateful to JP, for his work on my TT101 and eventually for replacing the so far no problem MN6042 in my Mk3 with his discrete circuit. I've posted here on my interaction with JP in the past.
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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I posted this as a new thread, but thought it would be helpful here too. I've owned my Technics SP-10MK3 for several years now. During that time, 3 or 4 of the vintage MN6042 chips have failed in the control unit. My chips have failed altogether, rendering the table unusable, or partially failed, rendering the pitch control unusable, but the table otherwise works. 'Works" may be unfair, since its wow and flutter figures (using the Analog Productions test record and iPhone Feickert app) worsen significantly, but are still good enough to embarrass many turntables. This chip drives the quartz synthesizer pitch control and LED display. As any owner of the MK3 will tell you, this is the Achilles heel of the turntable. Many owners have invested considerable sums of money in these magnificent direct drive tables, and before now, the fear of losing the table altogether due to a chip failure loomed large. The table will not function properly without it and the chip has not been available for some time. As a result, many have squirreled away donor Technics tables which use the same chip, like the MK2 versions of the SL-1300, 1400, and 1500. JP Jones of Fidelis Analog, who has written in the Audiogon forums, spent the time to design a replacement for the MN6042. The most recent failure of my vintage chip was some months ago, such that the table played, but without pitch control and higher wow and flutter. Rather than using a backup MN6042 chip, I decided to try the Fidelis Analog replacement. JP says that he has never seen a vintage MN6042 operate correctly, even when they appear to be, and he's measured nearly a dozen now. JP also adjusted all other parameters in the control unit per the MK3 service manual AND looking for adjustment clues elsewhere, as well as utilizing his own processes he’s developed. According to JP, the service manual is wrong or incomplete in some cases. What I notice is that the turntable responds better at startup; i.e., it doesn't start with that incredible torque, overshoots, and then corrects. By the way, JP is fantastic to work with - a consummate professional who does what he says he will do. For quick background information, my MK3 has the excellent Krebs modification, which I've written about on these forums before, and the excellent Porter plinth. I alternate different cartridges in the SME V-12 and 12" Graham Phantom 3 Supreme tonearms. I received the control unit back. After spending time listening to many records, it's clear that my MK3 has been sick for a very long time. It now sounds fantastic. I've never heard this table sound so good. It has analog tape smoothness. (I have several reel to reel machines and master tape dubs, so this is not a throw away comment). I've always liked that about the MK3. When it has a healthy vintage chip in it, it has this smoothness. Even more so now. Now what is blowing me away is this incredible, unassailable energy and drive. This table is unfazed by anything. I can hear and follow complex rhythmic structures like never before. And it has the huge soundstage and incredible detail to go with it. Massive, perfect-pitch bass. I'm loving it! This chip breathes new life into the Technics SP-10MK3. |
I now realize that you guys may be referring to the area UNDER the platter. Yes, mine is painted in that area. Only the exposed outer rim of the circular escutcheon is brushed alu or chrome or whatever. I remember going to visit Julius Futterman, in 1979, in his 2-room factory just off Broadway on 72nd St. There to pick up my new pair of H3aa amplifiers. I envision you toiling away in a similar space. I'm from New Haven, by the way. I'd never give up my L07D. How does the PS-X9 stack up among these great DD turntables? Best-groove, I don't know if you were referring to me having both a Mk2 and Mk3, but I sold off my Mk2 when I bought the Mk3. I don't own a Mk2. I do own a Denon DP80. |
Hi Lew, I don't have any pictures of yours that show the finish, but I thought it was painted. I've had a couple TT-101 through here since yours. This one seemed like a nice candidate for refurb. I'm not sure what its disposition will be as I've a PS-X9, L-07D, and a second MK3 in the refurb queue for my personal collection. I hope you had fun in NYC. It would've been fun to meet you regardless, though I was at our house in CT over the holiday. I'm working on some other improvements to the MK3 controller, so waiting may be in your favor :) |
Wow big turntables Technics mk3 and also mk2. I finished these days to restructure my Mk2 working about 18 months but only in limited time ....... but I'm happy because everything is back exactly like new.After a while I will also restore the TT-101 and aesthetically and electronically have big problems and is not perfect. |
Congratulations, JP. Perhaps having my TT101 in your shop had something to do with your pursuing the new purchase. So far as I can tell, the finish on your escutcheon (the decorative rim that shows above the plinth and bears the switch panel) is the same as on mine. Yes? I'll check my SN and report it here. My TT101 was an "export" version, in that it can be adapted to work on 100V, 120V, or 220V, by selecting among power transformer primary windings. I read that these were sold to US service men stationed in Japan, probably among many others who needed other than 100VAC. Although my TT101 was not NOS, it obviously had had very little use prior to my purchase of it. Possibly this is because the tiny crack in the PCB, that was causing it to fail intermittently, plagued all previous owners, as well as me, until JP identified the problem and repaired it. I was in NYC for Thanksgiving and several days thereafter, and I thought about bringing you (JP) my SP10 Mk3 PS, so you could install your chip and re-calibrate it, but in the final analysis I figured it was best to send you the PS, when the time comes. Meantime, I have no problems with the Mk3. |
Hi Halcro, Not NOS, but rather good shape considering. The main bearing in this one is in spectacular shape - extraordinarily smooth. Yes, we're talking about the same area. The exposed bit is brushed, and the inside bit is unprepped. The full piece is anodized and therefore protected. On the other two TT-101 I resurrected that area was painted. |
Hi JP, It's so valuable seeing a complete NOS boxed TT-101.... Just like a vintage car 'barnyard' find..... The finish I'm referring to is INSIDE the casing with the turntable removed where you can see on mine there is no tarnishing on the aluminium? It would be great to hear the full story of how you came upon this 'virgin' example...👀❓ I hope I don't get reprimanded like Lew did for using that word....😎 |
JP and I had a conversation regarding his TT-101 outer rim not being painted but brushed, where as mine and others we have seen are the painted version. His serial # is shown in the pic's so I'm curious if anyone has a later serial # than that shown and is painted. Unfortunately the location is awkward to see if mounted in a plinth. |
Hi Halcro, The top on this one isn't painted like most - it's brushed and anodized. The discoloration you see is what the raw casting looks like. http://fidelisanalog.com/wp-content/uploads/sites/3/2016/11/IMG_2102.jpg |
Having mentioned seeing some pictures of a boxed TT-101 some time ago and confirming the leather type mat being a originally supplied item, member JP has publicly posted pictures of his find. http://fidelisanalog.com/2016/11/25/barn-find-victor-tt-101/ |
Halcro was/is very clever at posting his photos on one of the on-line websites and then quoting the URL here. Others have done the same. Probably that is what we should do too. Or one could possibly put the photos on the System page here on Audiogon; I tried that a few months ago but could not make it work. I already do have some old photos up there. Yes, UA7045 is 9-incher. There is also a 12-inch version with a different numeric designation, maybe 7085, as you suggest. Someone on the Analog Forum mentioned that the 7045 has a relatively low effective mass, suitable for high compliance cartridges. Artisan Fidelity make some beautiful stuff, so I imagine your plinth is quite nice. PBNs plinths for Denons are fantastic too. |
lewm I must have missed any previous mention of your plinth adventures regarding the QL-10/TT-101. My new plinth for the TT-101 is a modified Artisan Fidelity "style" CLD design with sub plates to raise the 2 arm boards done in Rosewood. I'm really enjoying getting back into woodworking. Unfortunate that this site is stuck in the dark ages when it comes to some of the common niceties like pictures, messaging etc etc. No experience with the UA7045, that is the shorter of the series the other being UA7--85 or something? |
Dear Totem, I was unaware that you already own a TT101. One is enough for most of us. I bought mine in context with a QL10. Thus, I got a UA7045 plus the QL10 plinth, which probably has its own unique part number. Having already commissioned the creation of four different slate or partly slate plinths in my audio life (for Lenco, SP10 Mk2, Mk3, and Denon DP80, respectively), I was loathe to go through that process again. Plus, I was for 2-3 years uncertain that my TT101 would ever function properly, until I found JP Jones on another website. So, what I did was to re-enforce the QL10 plinth with one-inch thick pieces of aluminum that pretty much cover the available space flanking the hole in the plinth that accommodates the turntable chassis; I bolted them to the wood laminate very firmly, to create a CLD effect. Then I ditched the stock MDF armboard in favor of a machined piece of aluminum that exactly fits the rectangular space in the plinth; this alu armboard is in turn firmly connected to a second piece of aluminum running below it under the wood plinth proper. This seems to work quite well to create a very neutral chassis for minimal cost. If I knew how to post photos here, I would. I use an SAEC SS300 mat on my TT101. Mainly because it was sitting around unused. Tonearm is FR64S with B60 base. So, perhaps my tinkering days are over. I put this all together as described. It's sounding great with an Acutex LPM320 cartridge, and I am not inclined to mess around with the package. Even though another mat might sound a little better. Even though the mating of the Acutex with the FR64S might seem to be a mismatch. Is there any feedback here on the UA7045? Is its effective mass really so low as claimed by one source? |
lewm It has not been placed on the market as of yet, and mine is in very good nick so seems unlikly I would take the plunge. This is the first time I have personally seen an original boxed TT-101 with all the bits I also have a new TT-101 plinth 95% finished that will determine any future table decisions. The current owner is well known and I will leave it up to them to comment further. halcro The pictures I have seen show the original rubber mat on the platter and the other in its original packaging. |
I was sent a few pictures of a boxed TT-101 with the original bits and pieces yesterday, regarding the deer skin mat that Victor produced, Thanks Totem. Interesting....... Can you also confirm that it came with rubber mat at the same time? As that's the only mat that accompanied mine. |
Thanks for your note regarding the special dangers associated with using the MC2000, Raul. I neglected to mention that the TI Shield contains iron. After observing the problem with the MC2000, I was able to demonstrate to my own satisfaction that the permanent magnet rotor of the L07D motor was actually inducing a magnetic field in the TI Shield, which made matters much worse. Without the TI Shield, there is no problem, and I am able to run the MC2000 on the L07D. It would seem that coreless turntable motors, all based on the original Dual design, generate a magnetic field and EMI that is 90 degrees different in direction (i.e., in the vertical plane rather than in the horizontal), compared with the fields generated by typical iron core motors, because of the orientation of the stator and rotor. So, one has to be careful with them. On the other hand, my current feeling is that coreless motors are to be preferred in a DD design, for best sonics. |
ddriveman: 09-12-2016 2:21am "...one remaining disadvantage of DDs over belt drives i.e. motor vibrations going up the spindle." It is NOT motor vibration. It is bearing noise, which can happen in any drive system, whether it is direct-drive, belt-drive, idler-drive, or any other drive. The motor of a direct-drive turntable spins at 33rpm, which is half hertz, not reproduce-able in any audio system or loudspeakers. However, many belt-drive turntable motors spins up to 1800rpm, 30Hz, which is definitely audible, hence the need for isolation and decoupling. In DD tables, motor noise is the least concern and in fact it is the most important ADVANTAGE over belt-drive because it has a single slow moving part. |
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lewm 5,047 posts 09-16-2016 12:39pm Geoff, I will have to chew on that mouthful for a bit, but can we agree that EMI has the property of "frequency"? Assuming you would agree, then in what way would EMI differ from "low frequency magnetic field(s)"? Permanent magnets per se do not exhibit the property of "frequency"; you need a coil AND a permanent magnet and relative movement between the two, to generate a pulsatile field. At least, that’s my story. the reason I call mu metal low frequency high permeability material is because it is normally used to absorb magnetic fields around transformers which are 60 Hz devices, hence the low frequency attribution. There is also high frequency mu metal for use around speaker magnets. EMI is equivalent to RFI. RF is radio frequency that is usually specified in GHz or MHz but can be lower. Radio Frequencies are part of the ElectroMagnetic (EM) spectrum. Magnetism itself does not have a frequency associated with it. It is normally specified in Gauss which is a measure of magnetic flux density. Another distinction is RF is light speed whereas magnetic fields have no velocity. So, to summarize we actually need to address BOTH EMI/RFI and magnetic fields in the audio system, the strongest magnetic fields being produced by current traveling through wire in transformers and produced by speaker magnets and weaker magnetic fields are produced by current traveling through any wire or power cord or cable. cheers |
Dear @lewm : That experiences you had with your Ortofon MC 2000 is " exclusive " of that extremely low output design: 0.05mv that needs very powerful magnets. I owned 3 of those gems and in those old times Ortofon gaves a serious warning not to have any single metal ( obviously that non-magnetic materials as aluminum is no problem. ) near the cantilever/cartridge and that's why when other cartridge manufacturers puts inside the cartridge box a metal ( magnetic. ) screw to mount the cartridge Ortofon puts aluminum one. I had that kind of experience but not with the TT platter but with the Shure VTF tool that in those times some production lots where not made it of non-magnetic metal. In my case I can't save my cartridge and send it to Ortofon to fix it. So, be carefully with. Regards and enjoy the music, R. |
Geoff, I will have to chew on that mouthful for a bit, but can we agree that EMI has the property of "frequency"? Assuming you would agree, then in what way would EMI differ from "low frequency magnetic field(s)"? Permanent magnets per se do not exhibit the property of "frequency"; you need a coil AND a permanent magnet and relative movement between the two, to generate a pulsatile field. At least, that's my story. |
Lewm wrote, "Geoff, I would have thought that "EMI absorption" is but a more concise term for "low frequency magnetic field absorption". Especially since my reading also tells me that the forte of mu metal as a shield is to block or contain EMI, rather than RFI. As I understand it, mu metal is not much good with RFI. Please correct me, if I am off base here." actually mu metal absorbs magnetic field, that’s why they refer to mu metal as high permeability material, it allows magnetic fields to permeate the material. The correct mu metal for transformers is low frequency high permeability mu metal. EMI is electromagnetic whereas magnetic fields are not electric, strictly magnetic, I.e., gauss the magnetic fields are absorbed not blocked or shielded. Mu metal might actually be good for RF since it is a metal alloy, mostly steel, like a chassis frequently. But conductive materials like ERS cloth are generally of no use against magnetic fields. |
Geoff, I would have thought that "EMI absorption" is but a more concise term for "low frequency magnetic field absorption". Especially since my reading also tells me that the forte of mu metal as a shield is to block or contain EMI, rather than RFI. As I understand it, mu metal is not much good with RFI. Please correct me, if I am off base here. L07D owners, including me, espouse the use of a shield between its platter and the stainless steel "platter sheet", which seems to be Kenwood's term for "mat". For a few years, I used TI Shield, when it was available from M Percy, in this application, and I reported that it did some audible good. Then I bought an Ortofon MC2000 cartridge and mounted it on my L07D. I immediately noted that the rotor of the L07D motor, being itself a large magnet, induced magnetism in the TI Shield, which in turn sucked my MC2000 down on to the platter, nearly collapsing its suspension, a very very bad thing. This observation forced me to remove the TI Shield from the sandwich, and I have lived without it since then. Apparently the placement of the magnets in the MC2000 (and maybe other Ortofon LOMC cartridges) makes it uniquely susceptible to this problem, because I never had experienced it previously with any other brand or type of cartridge. I know that Dave Garretson used ERS cloth on his L07D platter, instead of TI Shield, and I wonder whether ERS cloth would produce the same induced magnet problem, probably not. However, I always thought that ERS cloth might have the negative effect of impeding energy transfer between the platter sheet and the platter, on an L07D, which is why I have not tried it up to now. Any comments appreciated. ERS is not quite as good a shield as was TI Shield, as far as I can learn from my reading. (It's a very complex subject.) On my TT101, I use an SAEC SS300 mat that was hanging around the house, which I tell myself adds some shielding effect between motor and LP surface. I am using an Acutex LPM320III cartridge in an FR64S, on the TT101, and I perceive no problem that could be ascribed to EMI or RFI, so I don't worry about it. In fact, that combo is sooooo surprisingly good that I am loathe to experiment further. |
halcro OP 1,983 posts 09-15-2016 6:47am Yes.....I wrapped Mu metal around the power supply of the Victor TT101 and the results mirror that of sampsa. No effect or better without. The metal screen/cover to the motor unit (when properly grounded) does the job it’s supposed to do.... It should probably be mentioned that the grounded screen/cover and the mu metal wrap have entirely functions, the screen function is RFI/EMI absorption whereas the mu metal function is low frequency magnetic field absorption. I’ve had good results wrapping large toroidal transformers and medium size rectangular transformers with low frequency high permeability mu metal; I actually wrap them twice leaving a small gap between the two layers. Better safe than sorry. cheers |
ddriveman: I tried the mu metal shield and ERS paper on my Yamaha GT2000 between the original platter and the copper platter mat. I found the ERS paper to give more refined highs, but that could have been due to its damping effect as a slightly soft layer between two metal layers. The mu metal didn't seem to have a beneficial effect and may have had a slight negative one. Anyone else with experiences? |
Centrifugal force (Latin for "center fleeing") describes the tendency of an object following a curved path to fly outwards, away from the center of the curve. It's not really a force; it results from inertia — the tendency of an object to resist any change in its state of rest or motion. Centripetal force is a real force that counteracts the centrifugal force and prevents the object from "flying out," keeping it moving instead with a uniform speed along a circular path. Centrifugal = imaginary Centripetal = real |
Aaarrrggghhh. You’ve done it again, DDrive. Stop already with the "motor vibrations going up into the spindle". This is not really a problem with a direct-drive turntable. As I mentioned on the other thread, DDs are subject to bearing noise, just like any other type of turntable, and to EMI because the motor is close to the platter surface and thus relatively close to the transducer itself, compared to a belt-drive and some (not all) idlers. But DD's are not much subject to mechanical vibrations due to the motor, unless via a circuitous route via the chassis transmission of vibrations that in turn might reach the bearing. The motor when producing torque also exerts a force on the chassis, opposite in direction to the force on the platter, which is why, maybe, DD's sound best with rather massive chassis'. I also took a look at the Arche website; in my opinion, that platter mat is designed for belt-drive turntables, wherein motor vibration CAN in fact be transmitted into the platter via the belt making contact with the rim. The most it can do for a DD turntable is to improve isolation of the LP from bearing noise or vibration, if that is a problem. I guess also that by the mere fact of elevating the LP further away from the motor, it might also diminish any EMI effects from the motor. Perhaps this has something to do with why it sounds very good on your turntable. However, I do not detect that EMI is a problem with my SP10 Mk3, although I have never measured the field strength at the platter surface. As you know, the Mk3 platter is quite thick and constructed of alu, stainless, and what I think is brass or bronze, all of which make for a pretty good EMI shielding effect. I can’t resist correcting Dover, because the opportunity to do so is rare. The force that keeps a body in orbit is by convention referred to as a "centripetal force", because it is literally "center-seeking". Think about a biblical type of sling shot. When you spin it around over your head, you are applying a force that keeps the projectile in the sling from flying off in a straight line tangent to the orbit. That force has a vector direction toward the center of rotation, your hand. I actually do not know where we got the term "centrifugal", but it is clearly a misnomer. What we think of as centrifugal force is really inertia, the tendency of a body in motion to continue in motion in a straight line, unless acted upon by an outside force. Inertia is observed as the result of the absence of a force. Centripetal force is applied via the sling to counter-act the inertia of the stone or other projectile in the pocket of the sling. |
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. |
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. |
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. |
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. |
