Hi Halcro. The bottom cover on the JVC is rather flimsy. I owned QL7 and QL-A7 before so I know they are not very rigid. I noticed you placed 3 footers right below that bottom cover. I know you like the nude style and no-plinth approach. Would it be better to have maybe some cylindrical footers, literally almost foot long, that support the chassis where the motor is directly mounted on? This way it can still qualified as "nude" and you eliminate that wobbly sheet metal and adds rigidity. Might be worth a try. I sold all my QL-7s so I can't experiment anymore. But I would like to know what you think.
I am a JVC fan but I came to the conclusion that I only like the ones that use coreless motor and QL-7 and QL-8 use core motor but the 101 is coreless and it's their top of the line and I am salivating here.... I would love to hear it compare to, say, a Kenwood L-07D, another coreless masterpiece.
Have fun!
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The TT-81 and TT-71 use the same CORE motor. The 81 uses more sophisticated electronic drive than the 71. Now, the TT-101 is a completely different beast. It uses a CORELESS motor and a "double bi-directional servo" in the electronics. So it is no surprise that Aigenga prefers the 101 over the 81. I have no experience with the 81 nor 101 but I have owned other JVC models and every time I prefer the ones with the coreless motor and even my non-audiophile friends noticed the coreless tables sound "smoother." It has a distinctive fluidity in the sound that's recognizable. I would LOVE to hear a TT-101. Much information can be found at the invaluable The Vintage Knob site. _____ |
My observation on coreless motors in direct drive turntables is that there are physical traits, at least the ones I owned and saw in pictures. Please keep in mind that I am not an motor engineer so my observation does not define what a coreless motor is. (1) The most obvious is that the rotor magnet is always above the stator coils and there's small gap between magnet and coils. (Less "grip" on the coils and, not surprisingly, less torque.) (2) The series of coils on the stator are ironless. (Helps to simplify its construction) (3) Lower torque than typical core motor. (Not as dynamic sounding or less "jump" factor.) (4) Many, not all, rotate smoothly even without the platter so they do not rely on the inertia of the platter mass like other DD motor. (This is an indication of its fluid sound.) Here are some examples and observe the physical similarities. JVC TT-101Sony PS-X7Sansui XRQ7JVC QL-A2Kenwood L-07DKenwood L-07DPioneer PL-50L IISony PS-X6Kenwood KD770DDual 701Brinkmann BardoHalco: "Doesn't it seem odd....if a coreless DC motor produces no cogging and sounds so 'fluid', relaxed and unfazed.....that a manufacturer would be foolish to even contemplate an alternative design?" Coreless motors were utilized in most later models of many brands, especially in the late 70's and early 80's. Pioneer shifted to coreless motors in almost all their later models. Kenwood did the same starting with KD-770D and KD-990 -- I don't believe the KD-500, a model in the early years, uses a coreless motor. Sony used their version of the coreless motor called BSL (Brush & Slot Less) quite early in all their "PS-X" series. With the exception of Technics and Denon, almost all Japanese manufacturers shifted to using coreless motors in the late 70s and ealy 80's. Denon stubbornly stuck to their AC induction motor all the way through the 70s and 80s. The earliest use of coreless in DD table is not even in Japan but in Germany. Dual used the earliest motors in the 701 in 1973, few years before the use of quartz lock drive. The motor model is EDS-1000. Back to Halco's question. Many Japanese manufacturers did ask that question and they decided on the coreless motor. If given another decade to further develop motor in DD technology, I believe almost all would use coreless motor, given the trajectory of the trend in Japan. But CD ruined all of that. :( _____ |
Lewm: "The fact that Denon and Technics stuck with cored motors does not necessarily mean they were "stubborn"." Sorry, I did not mean to imply anything negative about Denon and Technics not using coreless motor. Perhaps the word "stubborn" was poorly chosen but was really intended to mean they did not follow the trend as they probably felt their DD development were mature enough to withstand the shifting trend. I know I like the sound of several Denon turntables, coreless or not. I know you like your DP-80. As for Technics, let me just say I am off the bandwagon.... but that's a different topic. Lewm: "does anyone know about the Grand Prix Monaco, the NVS, or the Teres Certus? For that matter, what about the Brinnkmann Oasis?" The only info on the Monaco I can find is from 6moons.com that says "The finalized Monaco turntable runs off a 5-8V 12-pole DC motor inside the main chassis." No indication that is coreless or not. No idea what the NVS uses. The Teres Certus uses a CORE motor from pictures I have seen of its innards. The Brinkmann Oasis is the same as the Bardo, except it has a plinth. The Bardo is the stripped down version of the Oasis for a lower price. Motors are fascinating indeed! _____ |
Lewm: "If you read about Kenwood's thinking in the design of the L07D, they actually did not favor high torque in principle. So they were not concerned with competing in that "horsepower" race." I think I agree with that thinking and from the sound of many DD turntables with coreless motors it only confirms that. I much rather have a smoother rotation than just high torque. Judging by the reviews of the Brinkmann Bardo, a low torque design, they are onto something and the impression is that the Bardo does not have the stereotypical sterile sound related to DD tables. _____ |
Oops, the posted image of the PS-X7 motor was supposed to be PS-X9, Sony's flagship. Sorry for the error. ______ |
The closest to the Dual 701 motor design is the later version of the Kenwood L07D motor because, like the Dual, it has two layers of coils except Kenwood made them in star shape to avoid patent infringement. Compare to the older version I think I would prefer the later one because the magnetic field is symmetrical, hence, I assume, more balanced rotation. If people who own both of them, I would like to hear about the sonic difference. Which version do you have, Lewm? Lewm: "I firmly believe there is such a thing as "good enough". After good enough, the rest is a hobby." Great quote! _______ |
The topic about the Dual motor and later generation of coreless motors in L07D and Bardo has been covered by an Audiogon member who is also an aerospace engineer, Wjsamx in a thread about the Brinkmann Bardo from last year, as you might remember reading it. Here's what he had to say: 06-15-10: Wjsamx
Dual came out with the first and only EDS (electro-dynamic suspension) DD TT motor, for which they've never gotten any credit. Being an aerospace engineer, I can tell you this type is the only true magnetic direct drive motor. The Technics platter is nothing more than a magnet that sits in a rotor, is configured horizontally, which essentially becomes a standard motor stabilized by tach signals and OCD type electronics. The Technics motor suffers from pole jerking, magnetic drag, hysteresis, and requires a very large amount of power. The Dual EDS motor works like a modern magnetic railway. When the magnet is between 2 poles, the powers of the 2 poles are proportionate. In other words, if the magnet is dead center between the 2 poles, both poles will have 50% power, but if 80% of the magnet is over one pole and 20% of the other, the power is split 80/20 and so on in a linear fashion. It only requires 50 milliwatts of power to operate, since opposing magnets are the major force behind its propulsion. There is no need for quartz control. The hall sensors monitor the strength of the magnetic field within the system and hold stable regardless of fluctuating line voltage. A heavy platter is not required, and the technology of EDS actually allows the platter to (microscopically) levitate when it is operating, significantly reducing typical negative spindle and bearing contributions. This motor is dead silent. Unfortunately this EDS motor never received recognition and was very expensive for Dual to manufacture. At one time, Dual had 3000+ employees and completely made 100% of their own parts and motors in-house. To compete and save money, they "cheapened" newer motors and went along with the crowd of quartz control. BTW, the motor in the Dual CS5000 is an EDS type motor, although it provided belt drive. It seems that the Brinkmann DD motor is nothing more than a new type of Technics DD motor. The fact that the coils are not totally equidistant means it's "pushing" and "braking" in an un-uniform manner favoring one side. I believe they bandaid and hide issues by the use of a heavy platter. I'm in no way discrediting other manufacturer’s contributions to DD TT technology. Technics may have been the first to the commercial market with DD, but Thorens developed and patented the first DD motor way back in 1929. With respect to the discussion of "magnetic direct drive", Dual was the pioneer and implementer of this type of DD motor. Technics and other manufacturers have nothing to do with this type of motor as their DD motors act more like stepper motors. So the correct timeline is Thorens invented the first DD motor, Technics was the first to market the DD TT, and Dual was the first, last, and only to invent and market the EDS magnetic DD motor for use in turntables. 06-16-10: Wjsamx
Dear Lewm, There are 2 different motor designs for the K07D. The initial Kenwood motor that looks similar to the Brinkmann (and the Dual) but with 6 red coils was a patent infringement on the earlier Dual design. This is why Kenwood had to later change the design to the green star shaped coils, which you can see are not asymmetrical. Kenwood and other Japanese manufacturers thought they could get around the patent issue by using a different number of coils, placing them asymmetrical, compensating with electronics, and changing the specs. It was very common practice, and still is today, for manufacturers to purchase competitors products, completely disassemble them, study the design, and attempt to deviate enough in their own design to try and beat any patents. The Dual EDS motor had 8 double field coils in symmetry with a special conductor plate below it. The magnet was made of barium ferrite and had 8 pole symmetrical magnetization. The electronics in this system were so minimal compared to others that it fit on a round circuit board the same diameter as the bottom of the motor (5 inches). The motor was one complete assembly including the electronics. The platter just fit on top of it. In regards to the Brinkmann motor, I can't understand the reason for the odd placement of the coils. One would think there is a dead spot of power in its rotation which is why I believe its concept is to push and brake. The motor seems by design to only pulse power to the rotation as needed. Once the heavy platter is at speed, the energy within its mass is creating the needed centrifugal force for rotation. The tach feedback will sense speed deviation and only micro-pulse the "motor" as necessary to keep the platter steady at speed, like cruise control. Judging by the size of the motor, it's not meant to "direct drive", it is just too small and weak. It's really a "soft drive" system. Weak micro-pulses of "magnetic" power to the platter would certainly not create a large impact on such a heavy platter, thus eliminating any cogging effect. I do like it's simplicity, and it must obviously work, although they don't advertise any specific specs other than it takes 12 seconds for the platter to reach speed. The white pages on the Brinkmann motor suggest they are using a non-standard 22.5 degree angle on the coils with an 8 pole magnet, claiming that the overlapping magnetic fields reduce cogging. Isn't it strange that this Brinkman motor is very similar to the Dual EDS motor, which has 8 coils instead of 4, both use the coils at a 22.5 degree angle, both have hall sensors, and both have 8 pole magnets. I guess the Dual EDS motor patent has long expired. Essentially, one can get a Dual EDS motor, drop it in a plith, and have a Brinkmann for about $200 + tonearm. It might be ugly, but it won't cost 8 grand. Honestly, and with sarcasm aside, if I were looking for a new TT, I'd consider the Bardo, but only after having a demo.
Have a look at Dual EDS motor:
Exploding view of motor - - - & - - - Cutaway view of motor
Brinkmann white pages:
Brinkmann whitepaper in PDF file A lot to absorb but fascinating stuff to read about motors. :) ______ |
Lewm, I was hoping you would click on the "Kenwood repairs (including three L-07D !!) prompt and click on any one of the L-07D buttons. (Obviously I am a finger clicking happy internet search fiend!) Check out all those dozens of hi-rez images of repair parts. Amazing clarity. Lewm: "I think the field created by the coils would average itself out. (I also think there would be a limit to the odd spacing where once reached the field would no longer be able to average itself out and would result in a dead spot on each rotation.)" He did mention that the Bardo works in a "soft drive" approach and, perhaps the L-07D might also work in similar way: Wjsamx: "In regards to the Brinkmann motor, I can't understand the reason for the odd placement of the coils. One would think there is a dead spot of power in its rotation which is why I believe its concept is to push and brake. The motor seems by design to only pulse power to the rotation as needed. Once the heavy platter is at speed, the energy within its mass is creating the needed centrifugal force for rotation. The tach feedback will sense speed deviation and only micro-pulse the "motor" as necessary to keep the platter steady at speed, like cruise control. Judging by the size of the motor, it's not meant to "direct drive", it is just too small and weak. It's really a "soft drive" system. Weak micro-pulses of "magnetic" power to the platter would certainly not create a large impact on such a heavy platter, thus eliminating any cogging effect." It reminds me of the belt-drive school of using weak motor to nudge the heavy platter to keep it up to speed and let inertia and flywheel effect take over. After all, Brinkmann is a mostly famous for the belt-drive turntables so they might be approaching DD with a BD mentality. Hey, if it gets the job done, I have no problem with that. If it sounds good to you then that's what matters. I have some JVC motor with asymmetrical coil layout and they sounds very smooth to me. But I have to say the Dual 701 motor has a harmonic richness I don't hear from most DD tables and whether that has to do with its symmetrical coil arrangement or not, I have no idea. Lewm: "He said or inferred that the Dual CS5000 would have an EDS coreless motor. But based on what I read at the Dual history website, that may not be the case. Just what models of Dual DO in fact have the EDS motor." On the Dual Reference site, it does say the motor is "EDS 5000 System." It's a belt drive turntable so I don't know if the motor is usable for idler drive purpose or not. The most famous EDS motors are obviously in their two DD tables, 701 and 721. _______ |
Wahwah: "However, no mention so far that Goldmund and Micro-Seiki
used JVC core motors. Anyone care to elaborate on this?" From the few pictures I saw of the Goldmund and Micro-Seiki motors, they are not coreless motors. The motors are definitely made by JVC but they are not the later coreless version. They are similar to motors in turntables like JVC QL-5 and QL-7, DC core motors. I have used those JVC turntable models with core motors before and I prefer the later models with coreless motor. That's why I am not surprised someone prefers the Dual coreless motor in the Goldmund after replacing the stock Papst or JVC motor in a repair. _______ |
There appears to be some confusions regarding Dual motors. Maybe I am the one who is confused... Let's answer each question one at a time. Nandric: "As I or 'we' (Lew included) thought there are at least two
Dual motors: 701 and 721....... Lew suggested to use the Dual motor for his Lenco. I have no idea what to do with my specimen." Yes, there are two Dual direct-drive motors. EDS-1000 from 701 and EDS-1000-2 from 721. 701 uses a heavier platter and 721 uses a lighter platter. From what I read and if I understand Lew correctly, he wants to use the EDS-5000 motor from the CS-5000 belt-drive turntable and apply that to his Lenco, which is doable, and it has nothing to do with the 701/721 motors. I don't see how you can use the EDS-1000 and EDS-1000-2 motors for the Lenco since the Lenco is an idler drive design and the 701 & 721 are direct drive. I don't know what "specimen" you have or what exactly you are trying to do. Please elaborate. "Your contribution was primarily directed to the Goldmund Studio problem." The earlier question(s) was directed at the Goldmund issue so I answered accordingly. I must add that I would only repair the Goldmund using the Dual motor if the Goldmund platter would fit over the Dual motor with no or very minor machining. Otherwise, your Goldmund is not a Goldmund anymore and you're better off just transplanting the Dual motor onto a custom plinth and make it a stand alone arm-less direct drive turntable. "We thought that if this motor is something very special some other applications would be interesting." The EDS-1000 and EDS-1000-2 motors are, indeed, very special and is great for making your own direct drive turntable. Here is a gallery of pictures of a 701 and its innards. Have fun! _______ |
"As I already stated my hope was based on Lew because he seems to like to mess with all kinds of TT's in his garage(?)." He sounds like my kind of guy! :) The inquisitive mind is a wonderful thing. _______ |
Hi Chris, Hi Chris, Hi Chris, Hi Chris, Hi Chris, Hi Chris,Hi Chris, Hi Chris, Hi Chris, Hi Chris! (Now, that was easy.)
I really like your spiked SP10. I think that makes a lot more sense to me than just letting the bottom cover sitting on footers. Some may called it plinthless but I consider the SP10 chassis as a metal plinth (the real RAW turntable is the DD motor and platter) and having it rigidly spiked to the platform makes a lot of sense to me. Hey, at least it sounds good to you. I am familiar with the bottom cover of the kind used on the TT81 or TT101 as all my TT71 from QL-7 and QL-A7 (which are all sold) use the same kind of bottom cover so I am really curious about the sound when the TT101 is rigidly spiked to the platform. I think Halcro needs an adaptor ring to do that experiment. I look forward to sonic report in the future.
Let me comment on your Youtube video here: Cool!
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Halcro, I was just browsing around in the Canuck Audio Mart member gallery and found these pictures that reminded me of your system. There's even a YouTube video that he says "showing Symposium Rollerblock Jrs supporting an Isolated Turntable Armpod (Steel) that weighs 18.9 lbs. The idea using the Jrs. is from an audiophile friend in Europe." _____ |
10-13-11: Halcro:
"Doesn't it seem odd....if a coreless DC motor produces no cogging and sounds so 'fluid', relaxed and unfazed.....that a manufacturer would be foolish to even contemplate an alternative design?" You look at the release of the models chronologically, then you realize all coreless motor models came out in latter days. Once they went coreless, they stayed coreless. This is the same trend in other brands such as Kenwood, Yamaha, Pioneer, Sony, Sansui, etc... As far as I remember, the only two major brands stubbornly stayed with non-coreless motor was Denon who kept using their induction motor through out and Technics. Pioneer's top of the line model was the P3 and latter P3a (linear motor). It was not coreless motor but it was too popular in the market place and too developed to change such flagship model. But in the models below that, they did switch to coreless motor. One example is the PL-50L, core motor, and the latter PL-50L II, coreless motor. Looking at it historically, the trend in DD design is that by 1975 just about every table is quartz locked ( the "QL" in JVC models) and 1977 point on to early 80's, many Japanese manufacturers switched to coreless and stayed that way until CD took over the world. One physical feature of a typical coreless motor is that they shape like a pancake usually flatter than their core siblings. It's because a coreless motor has no iron core to wrap around and they shape like a series of air coils in speaker crossover and the rotor is right on top of the coils. I cannot scientifically confirm coreless motor is responsible for the fluidly smooth sound compare to other motor genres but from my own experience every DD table I heard using coreless motor has that sonic character. The first time I heard this smoothness was from a cheap Pioneer PL-300. It was outperforming its earlier more expensive siblings that got me curious about its motor structure. Playing records of violin solo gives a good idea of its smooth character. 03-26-14: Banquo363:
"There appears to be some disagreement regarding whether the tt 81 has a coreless motor or not. The vintage knob asserts that it does, but 'caligari' on this thread says he's positive that it does not." Nowhere in the text of VintageKnobs.com mentions that the TT81 is a coreless motor. It says "the motor of both versions is a high torque 12-pole 24-slot DC-brushless." A brushless motor is NOT the same as a coreless motor. After some research, the motors of TT71 and TT81 might be similar but they have different model numbers. TT71 uses M932A motor and TT81 uses M922A motor, according to their service manuals. The TT101 uses a M926 motor, by the way. _______ |
When I used the word "stubbornly," I did not mean to discredit Denon and Technics in their confidence of the maturity of their designs and technology. If they felt their chosen motor type resulted in good sound quality then there's nothing wrong with not following the trend. It was just an observation and not a criticism. Personally, I felt Denon DD tables produce great sound. And I'm sure Technics followers would say the same. As the saying goes, many ways to skin a cat, right?
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That specs page is for TT-71, which the writer is assuming its motor is similar to the TT-81 and I can say the assertion that it uses a "coreless motor" is absolutely wrong because I owned several TT-71 units before and I have looked into the guts of all of them, all core motors. I even looked into the specs pages of TT-81 and QL-A7 (uses TT-71 motor) from their service manuals and none mentioned "coreless" motor. Here's a simple proof. Just look at the first picture of the Amp8 repair page on a TT-71 under surgery and you can see the coils wrapped around the iron core. Axel, the owner and webmaster for vintageknobs.com might be an expert on Sony products but he's wrong on this JVC model. While the TT-71 is quite decent sounding, better than most Technics, it is not quite up to the level of JVC's other DD tables with coreless motor. The TT-81 might be a different story though and based on Halcro's testimonial he seems to like it quite a bit. _______ |
More observations I made earlier in the other thread. Here's the major clue from the vintageknobs page. Halcro did post some innards pictures of his TT81 but short of the inside of the motor. That TT81 looks awfully close to the TT71 motor. Yes, Halcro needs to take apart his TT81 to settle the score! :-D _______ |
04-04-14: Halcro:
"If the TT-71 and TT-81 motors are the same......why have the two models?" While I cannot confirm they are the same -- the motors have different model numbers but, I believe, have similar structure -- there's really nothing unusual about using the same motor in different models. JVC and others are giant corporations and they don't think like audiophiles. It was very common to use similar parts with different features. Sometimes with improved electronics they implemented into older models with added features to come up with a new model. That happens all the time in their integrated tables and I can think of at least 5 or 6 models share the same motor. The JVC QL-Y66F has the same motor and electronics as QL-A70, except one has automatic tonearm and the other with manual tonearm. Just look at Technics, the SL-1200Mk2 architecture had been used in 6 or 7 models with various features such as tonearm, plinth, suspension, automation, pitch control, etc.... The best view of the motor is actually from the top, remove the platter and motor cover and you can get a glimpse of the motor structure. Judging by the provided photos, the motor is canister type so it's very likely a variation of the TT71 motor which is a core motor. Please continue to provide us motor porn though. :-) At the end of the day, what matters is that you like the sound of the TT81 regardless of motor type. But the TT71, while decent, makes me desire more so I moved on to their integrated tables, which are sleepers but usually audiophiles are annoyed by their automatic tonearms. If many of these quality integrated tables have an armless version, history would have been rewritten. (If Lenco had more armless L75 models, audiophiles would not ignore them for so long. I know they do have the G-88 but...) The TT81 has advanced electronics so that might have pushed the performance to another level, evidenced by your approval. My own observation so far is that I tend to prefer tables with coreless motor, they pass the solo violin test, exceptions are ones with magnet-less motors as found in Denon induction motor a la DP-60 or Sony PS-8750 or older Sony drag-cup motors with a copper rotor. Aside from top of the line models, many DD tables with traditional core motors as found in models by Technics, Pioneer, Kenwood, etc... do not float my boat. Of course, the motor is just one part of the turntable but in a DD system it's a major contributor to the sound. One can easily argue that the weaker torque of a coreless motor has a less dynamic sound and less drive or "jump" factor in character. So at the end of the day, find what you like is what matters. Audio is like food for me, I'm all about flavors and colors. Lamb chop is great but on some days I just want a salad. That's why we have multiple turntables! I'm sure someone (Raul?) will jump at me about neutrality, faithful to the source, bla bla blah... ______ |
04-04-14: Banquo363:
"The english flyer for the jvc ql8 has a small black and white pic of the tt81 motor. Take a look and see if you can tell whether it's a coreless motor or not." Good find! TT-81 motor - & - TT-71 motorYep, just as I suspected. The TT-81 motor is indeed a core motor, same structure as the TT-71 motor. Notice the coils wrapping around an iron core? You just save Halcro the hassle of taking apart his TT-81. :) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Timeltel, I like your tinkerer's spirit. :) ______ |
Lewm: "The earlier Denons with induction motors: did they employ servo feedback as well? It is hard to imagine how that would work well. Did DP6000 use induction motor?" The one I'm know for sure uses induction motor was a DP-755, an old table without quartz lock that I used to own and saw the gut myself. In the Amp8 website there's no picture of the DP-6000 motor but there's a similar looking DP-3000 that uses an induction motor. I believe all the 4 digit series tables have induction motor and they all use a tapehead reader for servo. The later 2 digit series such as DP-75, DP-80, etc... went back to motor with magnet but retained the tapehead servo system. Halcro: "HiHo, Your interest in the Victor motors seem to have been ignited by your experiences with the TT-71.....is that correct?" Long story. I can say it is one of the tables that got me interested in JVC products and DD genre again. Technics SP10Mk2 was my table for the longest time, over 10 years before the DD revival. Always got laughed at by my audiophile friends for not using an "audiophile approved" table a la Linn. But I ignored the noise. Then there was a period I didn't work so I had all the free time to experiment. For whatever reason I didn't use the SP10 and started exploring belt drive and got into the Empire 208, still an excellent table. I just missed the conciseness of the DD and low noise so I decided to give DD another try. I bought a bunch of DD tables for experiment, TT71 was one of them, also included models from brands like Pioneer, Denon, Kenwood, Sony, Technics, JVC, etc... Up to that point I hadn't encountered any table with coreless motor and then one day I got to listen to a dirt cheap Pioneer PL-300 and it had a smooth quality that reminds me of belt drive so I gutted it out and discovered it had a coreless motor. Ever since I started looking for tables with coreless motor and they always have that smoothness I crave for. There are some non coreless exceptions, of course, such as Sony PS-8750 and Denon DP-60. You can call this smooth quality euphony or distortion or whatever. All I know it has a sound I enjoy -- neutral or not, I couldn't care less. It was then I relistened to the Technics models, SP10Mk2, SP25, SP15, SL12000mk2, SLM3, SLM2, etc.... none satisfied me. (Although the sleeper in Technics is really the SP15.) When I started with the SP10mk2 -- college days? -- I was deeply into punk rock and the bass dynamic and tightness is perfect for that musical genre. Playing The Clash's "Police and Thieves"was great way to show off the Technics. But as my musical taste expanded, it no longer could satisfy me in other music, that often criticized sterile sound is true for me. Technics does not represent the best of DD tables, there are many options. It's unfortunate many people dismissed the DD genre just because they didn't like the Technics without thinking there are at least half dozen worthy brands out there.You just have to be open-minded about it. So, that's the gist of it. - - - - - - - - - - - - - - - - Some of the quoted specs Timeltel provided were from Pioneer P3 and P10 and had nothing to do with JVC. Wrong links! It appears the prose was written using Google Translate program with very awkward phrases. Happy Listening, |
Richardkrebs, I agree with you on many points especially about torque. And I'm glad that you are able to enjoy a modified version of the Technics. I just wanted to add that the higher torque the higher cogging and it's a challenge to increase one without increasing the other. Your unit seems to overcome the sound that includes "a tension, stress if you will, to the presentation and a greyness that over time is downright irritating." Well said! I guess coreless motor offers a good compromise for me. Does that make me belong in the "low responsiveness camp"? Can I bring some Clash records for a spin? :)
I'm sorry that I sounded rather negative on the Technics line. I actually have fond memory of the SP10mk2 and, who knows, might even revisit it one day.
Happy listening!
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Thanks for elaborating, Richard. I am learning a lot about motor. Would you say the irritating "greyness" from the Technics is due to this high frequency "pulse" created by the feedback network? Can the remedy be applied to other brands of turntables?
Quite honestly, I don't really care what kind of motor is used in a turntable as long as it does not contribute that negative sound quality you mentioned. That jittery sound once heard is easily recognized but hard to ignore and I've been avoiding it ever since I switched to other smoother sounding tables. I'm glad there are technical people like you out there addressing the issue. It's about time to shut up the DD naysayers! :)
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Let me be clear that I never own an SP10Mk3 so I have no way of knowing whether it exhibits the gray-ish tone in Mk2. All my comments were referring to the Mk2 and the models below it. Just saying...
I have limited experience with Mk3 as my former employer has one and it's wonderful sounding every time I was at his house listening to it and since it's in unfamiliar situation I cannot make any valid judgment but at least it has been a positive experience. Lew's positive take only reinforce the notion.
I am only amused by all the Mk2 plinth making and trying to address something that has little to do with vibration control as if a magic plinth will miraculously fix the inherent design issue of the drive system. I'm sure a good plinth can improve noise level, transparency, etc... but that grayish tone aint gonna go away.
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Don't deny it. It is witchcraft!
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Yep, damn him! You can whisper some of the witchcraft his way. Ha!
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Surprise, surprise! Thuchan is, his words, "now back to the DD camp." Welcome back! :-) PS, That's one lovely looking Sony PS-X9. . |
I believe Lewm is right that there must be a cold solder joint somewhere or a pot that needs lubrication where the wiper has intermittent contact or a crimp connector eroded over the years and lost contact. These kind of things require only the merest movement to knock it out of wack. The ghost is in the detail.
Happy witchhunt!
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To create a link via Audiogon instructions: Using Markup Tags. Pictures are links only as Audiogon has no database to store picture files therefore one must upload photos to outside website a la photobucket, tinypic, imgur, etc... . |
Halcro, I understand your concern and it is a valid one. When I used a DD table to drive a passive platter, I had to use the speed control and that required defeating the quartz lock feature to be at variable pitch since the two platters are not identical size. I confirmed the speed using a KAB strobe and it was rock solid. Of course you can always use the Sutherland Timeline if possible. I also did a experiment of using two identical direct drive tables one driving the other, one to one ratio, and able to retain the quart lock. And the sound is better than direct drive alone. But I ran out of table space! :)
I think using noncompliant material lessen the problem. I'm sure using a stretchy belt will throw off the speed in a weird way but, hey, we might like the sound! :)
Anyway, it's worthy experiment if you already have all the components and time. It's reversible. You have nothing to lose. The reason I did that was just so sick seeing expensive belt drive turntables using cheap flimsy motors and all that money was poured into the fancy platter for blinks.
Happy listening!
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For those who have a JVC TT-101 should check out this YouTube video. DIY thread drive turntableLooks like someone turned the TT-101 into a belt drive motor! Using string or thread that has no compliance, it retains the accuracy of the direct drive system with the isolation of belt drive. Halcro, you should use the TT-101 to drive your TW Raven. :-) I have used a Technics DD table that has pitch control driving a passive platter before and it worked! . |
Thank you for the kind words, Halcro. As a person with limited means, I'm more of a daydreamer than a "thinker." As for the "doer" part, I've been really lazy lately so I am more of a slacker. There you go, I'm a daydreaming slacker bum! :) I didn't document much when I was experimenting so I don't have much to show. Here's one picture of using the guts of two Pioneer PLL-1000 tables, one driving the other via VHS tape. I even stuck a Lenco idler wheel in between at one point. Each has their own sonic signature. The tape drive version sounded the most balance. But when I switched to a JVC table I almost couldn't hear the difference. The idler drive one always sounded different, more robust and juicy. Nothing too scientific but it was all fun. :) PS, This forum is more about validating one's (or invalidating other's) purchase decisions, almost like a consumer guide. It's a different platform from other DIY forums I frequent. I do enjoy out of the box thinking so this thread is quite nice. :) . |
Instruction on setting up the RS-1A tonearm using underhang scheme. I believe the arm uses the tangential point (or reference point) right in the middle of the platter which is 3 inches away from the spindle about 76mm radius. "Structure & Features of RS-A1 Tonearm" by Shirou HoriiYou can use that as a starting point to experiment with the SAEC or other available arms. . |
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For a long time I agreed that the tonearm and the platter should resonate in unison to avoid added distortion. But after reading about good results from the separte armpod approach, I started to question my original thinking. I realized the tightly coupled arm to platter approach would work only if the stylus is also tightly coupled to the arm, that is, extremely low or no compliance at all. But most cantilevers are attached to a piece of compliant rubber and that automatically decouples the stylus from the rest of the arm so the separate armpod becomes really inconsequential and therefore it's not surprising that it can sound good reported by those users. That's just my current thinking and I'm open to other possibilities.
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I have experience with the JVC QL-A7 and QL-7, both using TT-71 motor unit. Great for the money. But the gems, as far as pure turntables are concerned, are actually in the integrated turntables such as QL-Y7, QL-Y66F, QL-70A, etc., all have coreless motor and smooth sonic. The QL-Y66F is the same as QL-70A, except one with electronic arm and the other is manual. Electronic arms are not reliable unfortunately but the motor unit is stable and reliable. It's high time for people to look into those and install your arm of choice. If all integrated DD turntables have an armless version, history could be rewritten. But audiophiles usually overlook them because they want to use their own arm and I don't blame them. But they're missing out on gems.
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Correction: the model should be QL_A70, not 70A. I have keep these model numbers straight in my head. :)
Sorry for the confusion.
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Correction of correction. Oops. The above should read:
"I should have kept these model numbers straight in my head."
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Banquo363,
I never had a QL-A95 so I cannot be sure. Most of these tables have ribbon cable connectors from tonearm to the main board so you can disconnect them and the table will work manually. You can just add a armboard to cover the hole and a cut out for your am. The mod should be reversible. Most JVC arms are 10" so a typical VPI 10.5 or similar should work. I have the a QL-Y66F and the automatic electronic tonearm never works right so I uninstalled it by disconnecting all the ribbon connectors and I just need to machine a piece of armboard for it. Another approach is to make a larger plinth and so you can keep the stock arm and mount another arm in the back. The A95 plinth seems to use a lot of wood around the motor unit so adding arm shouldn't be too hard. The stock arm seems like a mechanical arm and should be reliable, unlike the electronic one that uses field coils to adjust VTF and azimuth and damping. The Y66F arm on mine was a nightmare! The Y66F is a bargain, arm or no arm.
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Some pictures of the QL-Y66F showing the tonearm attachment.
http://photoshare.ru/photo11191273.html
http://stat001.ameba.jp/user_images/20140126/12/kzaxiom/eb/3f/j/o0800060012825505017.jpg
Cut away picture of A95:
http://audio-heritage.jp/VICTOR/player/ql-a95.html
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The best example about integrated turntable is the Lenco. Most Lenco models are integrated tables with stock tonearm but once audiophiles ditched the arm they are liberated and you can find all the creations in LencoHeaven site. I wish people start paying attention to other DD tables. Even with the Technics SL-1200MK2, people replace the stock tonearm.
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Halcro: "I'm not sure what you mean by "integrated turntables"?"
Integrated turntable just means a turntable comes with its own tonearm, unlike TT-101 or Technics SP-10 that allows you to use your own tonearm.
The QL-A7 qualifies as an integrated table, the same as a QL-7. It is essentially a TT71 with a semi automatic tonearm that has auto armlift at end of record and auto stop. The "A" means automatic version of the QL-7. I owned both QL-7 and QL-A7. They were my introduction to JVC turntables. Their later integrated turntables feature coreless motor that has a sound my ears are more cottoned to, such as QL-F6, QL-Y7, QL-Y55F, QL-Y5, QL-Y66F, etc... and the aforementioned flagship integrated table QL-A95.
Back to the QL-A7, the later integrated turntables are rather more complicated as they are completely automated with electronics that can adjust VTF, antiskating, damping, all on the fly with knobs on the front, like the one in the QL-Y66F. Very complicated electronically. It's great when it works right but it's a nightmare when it goes berzerk as it can kill your cartridge by applying too much tracking force by crushing the cantilever! For that reason I much prefer an old school tonearm like the one in the A7. Underneath the plinth of the Y66F, it has many ribbon cable connectors connected to the main board so it's a bit more complicated than the A7. Installing your own tonearm is doable but just have to be more careful.
The turntable section of these integrated units are very reliable, never had any problem with them. The electronic tonearms are a different story. If I can choose, I would like to have a QL-A70 as it has identical 14" platter and motor drive as the Y66F but with a more traditional tonearm. But the Y66F is more common and easier to find. Due to finance, laziness, and simplifying my life, the only table I am using these days is the QL-F6 with its stock tonearm mated with a Signet cartridge, hence my lack of participation in forums. It sounds satisfying to me. But the QL-A70 is always on my mind... I still have a beater Y66F in storage that, hmmm... I should put it into good use one day...
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Halcro: "Forgive me if I'm wrong....but I thought that only the TT-101 had the coreless motor?"
No, TT-101 is NOT the only JVC turntable that uses coreless motor. Look up some of the above models I mentioned.
I had a QL-Y7 briefly and sold it as a favor to a non-audiophile friend to replace his QL-A7 and he told immediately the sound is smoother with the same cartridge. I trust non-audiophile's ears than audiophiles, to be honest. Of course one can always argue they use different tonearms and it could be the attribute to the sound. But turntables with coreless motor that I heard have a fluid sound that I like and it's different from typical DD tables, a la Technics, almost like a belt drive but more concise and stable. That's just my own impression. YMMV.
There's a German JVC collector "JVC_graz" in some internet audio forums is very knowledgeable about all the different JVC models. Here's a picture of his collection of integrated tables.
http://www.vinylengine.com/turntable_forum/gallery/image.php?album_id=106&image_id=8637&view=no_count
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Halcro,
I have thought of the same thing before but JVC made their integrated turntables rather hard to do that because the circuit boards are laid out all over the place and wires are like spaghetti. After some research I believe the QL-A75 is the closest to what you are talking about. It's probably the simplest construction as the top plate or chassis contains all the controls and the circuit boards are all under the top plate so making plinth cut out a lot easier. I never owned one but I have similar QL-Y55F with the electronic tonearm but the main board took up the whole width of the plinth underneath. The QL-A75 is almost top of the line and I am sure it's a great performer even with its stock tonearm, which is an old school mechanical one so that's good.
Here are some pictures from a Japanese website:
http://blogs.yahoo.co.jp/gt2500jzz/34155439.html
The QL-A75 is rather hard to find though. And the A-95 is even harder!
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Another approach is to make an armpod or island for a tonearm, preferably 12", that can just swing over to whatever table you will be using. Of course, you have to remove whatever compliant footers so it wouldn't affect VTA or geometry. Pretty much the same concept as your "nude" approach. This way, you are not affecting the resale value of your stock table. Just another thought.
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Here's one forum member improving his JVC QL-A75 by adding mass and damping to the plinth:
http://www.audiokarma.org/forums/showthread.php?t=426693
Here's one that adds a SAEC arm bracket to the stock plinth:
http://www13.plala.or.jp/mj4018/we308l2.html
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Halcro,
With my JVC QL-F6, I use a Signet TK5Ea. The original stylus is on its last leg and needs to be replaced soon. I used to have a TK-7E but Audio Technica no longer make that kind of stylus so I sold it and I opted to for flexibility and kept the "Ea" type of body. I just reread your earlier post about the QL-A7 with the Signet TK-3Ea and coincidentally that's almost the same set up I had in my introduction to JVC! I was using a QL-7 with Signet cartridge. Fantastic sound!
Happy listening!
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Pryso, you are correct the typical 10.5" VPI base is cantilevered so it will not work to replace JVC 10", not enough clearance. What I had in mind was the first generation VPI Classic that uses the same base as 9"JMW in the Scout but with a 10.5" armwand. Good catch!
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PBNaudio/Peter, thanks for the link. Very cool. You're rewriting turntable history! Time to look into the JVC QL line. :)
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10-13-15: Lewm:
"Apparently, Mark Dohmann, one of the principles of Continuum, is now producing a tt on his own, for about $36,000 with a Schroeder LT tonearm, a relative bargain compared to the Caliburn." That Schroeder arm is NOT an LT model. The headshell offset angle and the lack of extra pivot point at the base gave away that it is not a pivoting tangential or Linear Tracking tonearm. http://www.monoandstereo.com/2015/06/thrax-audio-helix-1-ultimate-turntable.htmlThe Schroeder arm appears to be a carbon fiber version of the discontinued Artemis Labs TL-1 tonearm. |
Lewm, I think the Bardo and L07D both took a page from the granddaddy of coreless motor, EDS-1000 from Dual 701. Brinkmann Bardo stator coilsKenwood L07D stator coilsDual 701 stator coilsLewm: "On Technics. My early impression of my SP10 Mk3 suggests it lives up to the hype." That's good to know but unfortunately I can't afford it. I heard all the models below the Mk3 and let's just say I have moved on. I'll say this: when it comes to bass dynamics and tightness, the SP10mk2 reigns supreme so I suppose the Mk3 is even better? I do miss playing my punk records on the Technics though. ______ |
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