Vintage DD turntables. Are we living dangerously?
Hi Doron, According to Vintage Knob...the TT-81 has 1.3Kg/Cm starting torque against the 1.8Kg/Cm for the TT-101. I don't know how that relates to perceived performance as both decks are consistently immune to the the effects of 'stylus drag' even under three cartridges running simultaneously...😍 I also can't hear a difference in performance between the two decks in my system..... Regards |
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 Horii You can use that as a starting point to experiment with the SAEC or other available arms. . |
Correction - the lead-out starts at approx. 60mm and the record goes to 160mm, so I guess it would be more like 105mm from the spindle. I have a few records that are recorded much closer to the label. You'd have to experiment. VE has a free download protractor called Chpratz. It's a calibrated straight line with a grid all the way and calibrated with distance from the spindle. One thing that peaked my interest was a comment by one of the reviewers. He thought the shorter version of the arm sounds better - less resonance and vibrations. I was thinking of getting one of those straight arm DJ tables just to try it, but I couldn't bring myself to do it. Regards, |
Hi Halcro, You might have a problem with that. The arm is probably designed with at least 15mm overhang and with an SAE type headshell, chances are the cart will be too far forward. In order to achieve underhang you'll have to move the arm further back. If you have some kind of arm pod set-up, this might not be a problem. Otherwise I think you'll have to drill a new armboard. I have an arm similar to a Graham Robin and no way without remounting. I believe the alignment is 5mm toward the spindle from the center of the recorded part. That would be 95mm from the spindle, if I'm not mistaken. Regards, |
This tempts me to try my SAEC WE-8000/ST as a straight tonearm 😜⁉️ It comes with a ceramic off-set headshell but I use a whole lot of other headshells which I can use without twisting the cartridges as I currently do...😎 What do you guys think I should aim for as an underhang....bearing in mind the Viv Lab uses from 5mm to 20mm....👀❓ |
08-28-14: Lewm:In the August 2014 issue of Stereophile, Michael Fremer reviewed the tonearm and wrote something about the bearing: "The arm lacks a conventional bearing. Instead, the pivot floats on a dark, magnetic, light-viscosity, ferrofluid-like oil that you inject into a large opening at the front of the pivot housing. Before you do, the arm is too stiff to pivot; afterward, it smoothly glides on what appears to be a bubble of oil without visible means of support. According to inventor Akimoto, inside the pivot, a small ball floats on a “slimy rubber swimming ring that regulates the arc motion of the wand.” There must be a cup-like structure inside that holds the oil, and a vertical rod—the pivot point—that is somehow steadied by but floats within the oil. I couldn’t pull the arm to and fro, and yet it floated freely. Very ingenious, however it works!"It sounds like the arm might be a modern remake of the Gray oil damped unipivot design using "magnetic fluid." But the distributor claims the following: (1) Absolutely no mechanical contact at arm pivot bearing mechanism, resulting in highest sensitivity and maximum amount of howling margin (Which promises to reproduce rich but much tight base sound with no distortion, no muddiness, the most clear sound and wider dynamic range).So in the end, I don't know. . |
Lew, You mean 21mm short of the lead-out groove, which would be about 80mm from the spindle? Reducing torsional affects on the cantilever is extremely important and obviously a tradeoff for alignment error. The Viv arm won a couple product of the year type awards so it might be very good? I believe the pivot is held in place with some kind of magnetic fluid. http://www.highend-electronics.com/viv-labs.html Regards, |
Fleib, another such arm that preceded the Rigid Float is the RS Labs RS-A1. As you say, it uses "under-hang" and thus achieves tangency at one point on the LP surface. Both of these arms are in the realm of the crazy, but I can say that the RS-A1 really works and sounds way better than I would have guessed. Thus I am curious about the Rigid Float. What bothers me about it is the question of whether the pivot is really held "Rigid" by the floating bearing arrangement. I don't see how it could be. The instructions that come with the RS-A1 suggest 21 mm of underhang is optimal (stylus hits the LP 21mm short of reaching the spindle) but this is more a suggestion than a rule. Halcro, I agree that a 20-inch arm with a straight head shell would have very little tracking error because of its sheer length, and the skating force would be weaker than in most cases. But the trade-off is the potential for lack of rigidity of an arm that long, plus high effective mass. Interesting for sure, nevertheless. |
Halcro, Lew, A straight arm with no offset is normally set to one null point a little inside of the center of the recorded part of the record. I think this would correspond to 96 - 98mm from the spindle. There is an arm like that now called Viv Rigid Float. It has won some accolades. I've never heard it. "They" say the benefit is from eliminating most torsional forces on the cantilever. Regards, http://stereotimes.com/post/viv-lab-rigid-tonearm |
The prime cause is related to the fact that nearly all tonearms are mounted such that the stylus overhangs the spindle.Thanks for reminding me of this Lew...😊 I do think that in this case with his specially made 20" tonearm without an off-set headshell.....he probably also set it up on his pod without any overhang⁉️ I can't imagine what geometry he would use if he DID set up an overhang as he couldn't get zenith correct at the two nulls without twisting the cartridge...❓😎 |
Lewm/Pryso thanks for your concern. but the tech has no concerns about exploding caps or his ability to fix if any fail, even thou there are NO technical manuals available so he will be going somewhat blind again. This is the same tech that fixed my P10 and Halcro's DD's, making his on IC on the P10 so he is more competent than most - There was nothing wrong with the caps in the P10 either. The P3 was serviced by Pioneer Japan before I bought it a few years back. I actually slipped a disc in my back trying to move the P3 into the car, so off the radar for some time now. Does not mean I won't do it in the future, but anything this old can fail at any time. |
Ditto to what Pryso says. Downunder, you might consider finding another "tech". The guy you quote is not very tech-y. As Pryso says, the reason to change out the electrolytics has nothing at all to do with sonics (unless a leaky cap is causing a speed error already). It has everything to do with the fact that electrolytic capacitors have a finite lifespan. Which is to say that after about 30 years since most of our dd tt's were made, the lytics are near pooped. A leaky electrolytic (either electrically leaky, meaning that it can pass DC, or mechanically leaky, meaning there is goop all over the outside) can and will eventually take out an IC or a transistor that may be irreplaceable. Call it preventive maintenance, if you are having no problems. Like changing the oil in your auto engine at regular intervals. For a great tt like the Pioneer P3, do it. Dear Halcro, Headshell offset angle does have an effect on the magnitude of the skating force, but it is not the prime cause. The prime cause is related to the fact that nearly all tonearms are mounted such that the stylus overhangs the spindle. Thus the cantilever/stylus can never be tangent to the groove. (You are fond of Copernicus; now think about that other Greek, Pythagorus.) Since the cantilever/stylus is not tangent to the groove, friction between the stylus tip and the groove wall creates a force at an angle to the path of the stylus; a component of this force vector is toward the spindle = skating force. A tonearm with no headshell offset angle is not free from skating force. |
Downunder, I've never read a claim that electrolytic cap replacement would improve sonics. But I have read advice from respected posters who know much more about electronics than I do that they can dry up or fail in other ways with age. The danger is not that they simply quit working but that their failure may take out other components, some which may no longer have replacements (ICs). So your initial thought about "preventative maintenance" seems sound. I might look for a different tech. ;^) |
I was going to take my Pioneer Exclusive P3 into my tech to have caps etc replaced. He asked me what was wrong with the table. I said, nothing but a few audiophiles said to take it in for preventative maintenance to replace the caps. He said, changing caps will do nothing for the sound as they are part of the control the turntable speed in the dd table. With the dd tables, it either works perfectly, or it doesn't- simple. He said tonearm and cartridge will have more impact on the sound than any changes you do to the table, as long as it is working to spec. If it stops working like my P10 did, he will fix it. Good enough for me. FYI - Lyra Delos for its comparatively cheaper price is world class. Syntax is correct, it is more resolving than the more expensive Kleos. Cheers |
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. :) . |
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! . |
Thanks for the Link Hiho...😍 Very interesting.....and nice music as well...🎶 I have seen that done before...as well as two Micro Seiki turntables running in line....using the one motor and a flywheel arrangement..👀 I studied this arrangement shown in the video for a long time.....whilst being somewhat troubled 😧 without knowing exactly why......⁉️ (Answer to the puzzle at the bottom of the page...😊) This video demonstrates clearly how much 'thinking' some Japanese (and European) audiophiles put into the theory and philosophy of the turntable question...🔎🎼🔍💡😍 I love his obvious 'Copernican' view of the turntable surrounded by massive armpods 😘....and the 20" straight tonearm is fabulous...😜👏 He obviously prefers the ability to eliminate skating forces (no off-set angle on the headshell)....for the slightly increased distortion of 'tracking error'...⁉️ I wish I could see how he runs the thread from the heavy stainless steel platter mat on the Victor DD turntable 👀❓That is one massive 'pulley motor' 😎 Notice also his full horn speaker system....🔝🔚....obviously being powered by SET valve amps (although we don't see them 😰). Answer to puzzleThe advantage of the very best DD turntables over belt-drives IMO....is their ability to cope with 'stylus drag' due to their torque and correction circuitries. With the quartz-controlled motor attached to the platter and in close proximity to the stylus....any slowing of the speed due to 'stylus drag' is instantaneously corrected AT THE SOURCE..👍 When the stylus is separated from the correction circuitry by a thread a metre or more away.......the 'stylus drag' has a 'delayed' input which simply puts the quartz control 'out of sync'....😰 |
For those who have a JVC TT-101 should check out this YouTube video. DIY thread drive turntable Looks 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! . |
Nice use of emoticons, Halcro. One emoticon is worth a thousand tears. My TT101 is working, if I leave it powered up at all times, and if I don't move it, and if I run it at least once a week. With those stipulations, it's "reliable". I have heard it play music, but my new problem is that there appears to be a short within the UA7045 tonearm wiring, such that I have no right channel. I need to change the tonearm on the QL10 plinth. Interestingly, the Fidelity Research FR64S has a requisite spindle to pivot distance that is compatible with that of the UA7045, so I should be able to pop in my FR64S in place of the UA7045. I will do that one of these days, when there is no other "project" in the way. Also, I am enjoying the Beveridge 2SW speaker system so much that I tend to want to listen to music when I do get free time. Interestingly, if the TT101 gets balky, usually after I have not used it in a long time, the cure is to whack the (front) side of the plinth nearest to the control panel of the TT101, with the palm of my hand. Very unscientific but works a treat. I am very convinced that there is a bad switch or a loose connection between switches that is to blame for the finickiness of the table. |
Just completed a complete refurbishing / rebuilding of a Micro Seiki DDX1500 for a customer. These old machines are truly excellent. Did a speed check with the time line, over an entire album side the dot did not move from 23 feet across the room ! A nice little upgrade I did to was having the inside of the platter sprayed with Polyureah (Truck Bedliner), this silenced the bell like character of the platter nicely. PBN / Micro Seiki DDX1500 Good Listening Peter |
Hi Lewm Yes, I believe you are correct. Chris said he replicated the IC with 7 components? That is about how technical I got or understood. He did mention the Pioneer circuit board was the simplier of the three dd tables he has worked on.. The JVC and Demon were crowded and complex relatively speaking. Yes Henry, excellent work from Chris indeed and thoroughly recommend him to anybody. Thanks.😇 And yes gents, I will have Chris take a look and replace all the caps for safety. 35 years service is pretty good and they may last another 35, but as you said if they fail due to age it will be good to safeguard it not have it happen. I have asked my mate from Japan first to see if he has a Exclusive P3 Japanese service manual, but I doubt he has one, especially since Pioneer still service all Exclusive products in Japan. Cheers and happy listening to all with their timeless Japanese DD tables 😁 |
This guy Chris must be a gem, for sure. And by all means, Downunder, DO replace all the electrolytics in your P3. Like Albert says, you may save yourself a much thornier dilemma at some point in the future, if leaky caps eventually kill off an unobtainable IC. (But maybe there are no ICs in a P3 to worry about.) Now, onto the subject of "IC"s. It seems to me that they are not all created equal. There are some enormously complex and highly specific ICs at work in both DD turntables and in CDPs. Some of them have 16 to 24 "legs", and there are not even solder guns available to remove them from a PCB. That's why the common mode of repair is to throw the whole PCB away and replace it with a new one. Then there are ICs that self-contain a very simple circuit; I have to assume it was one of that type that Chris was able to replicate. |
Glad Chris helped you Downunder.....😀 His ingenuity, understanding and competence in all things audio are unequalled in my experience... I took back my TT-101 to have him adjust the variable resistors for the platter brake system. As I discovered....Victor added this feature to allow for the differing weights of various mats...and as I changed to only a thin Victor pigskin mat directly placed on the aluminium platter.....the brake system didn't perform as required. It took Chris precisely 20 minutes to adjust them ( one for 33.3rpm and one for 45rpm). No charge...😘 and they work perfectly.. I would waste no time in having him replace all the electrolytics in your P3. Since my TT-101 had its done....the speeds are consistently perfect 😜 |
...I assume a really competent/talented technician would have the necessary skills to copy an entire IC, which is what he did. Even if that were true, it takes all but a compact with the devil to locate such a person. Is there a N. American Chris Kimil? Not that I presently need one, but it would be good to have that name in the back pocket just in case. At any rate, congratulations on renewed life. |
Hi Albert I have no technical ability, however I assume a really competent/talented technician would have the necessary skills to copy an entire IC, which is what he did. Thanks to Halcro for recommending Chris Kimil, even thou he had replaced my Wilson tweeters. I did not realise that he fixed turntables. I am even thinking now of having the tech replace all the 35 year old capacitors on my Exclusive P3? |
My intermittent speed problems on my Pioneer Exclusive P10 - racing up and down and failing finally became permanent. Took the table into the tech and he said most probably changing all the caps would fix the issue. yesterday I got a call that the table was ready. When picking up he said that replacing all the caps did not fix the problem. he searched the entire web and no schematics on the table. He eventually found it was a faulty IC from the 45rpm control that did not switch off and would distribute noise/interference to the 33 IC control. these specific IC's had been long discontinued. So he studied a bit more and made his own! problem fixed. the interesting this was that the tech had previously worked on Denon and Halcro's JVC DD's. Even thou they look similar from the outside, the internals and design's of all 3 were very different as was the number of parts, complexity etc etc. I played it at home all last night and the speed sync's straight away and is playing beautiful music - fingers crossed it stays that was, but with the caps all changed on my 35 year old DD I have a fighting chance :-) cheers |
Hi Gary, I found your post of 9/16/13. I now know (once again) that your shield is made of mu metal and that the black stuff is auto interior material (which is exactly what it looks like). I probably also knew this 7 months ago, when you posted the info and photos originally, but the memory is fleeting. I found that same stuff on eBay that you have used. I Googled the eBay product, and there was some discussion that it is not as "good" as mu metal (it's a lot cheaper), but most conceded that it does work as a shield. I like your metaphor about squeezing a balloon, where you are describing what happens to the EMI when you installed the shield; the energy shows up elsewhere but not where you don't want it. Possibly, if you can ground the shield to the turntable, you would actually drain the energy to ground. But that may be tough to do. I am going to get used to the sound of the TT101 with no shield, then install a shield, perhaps using the very same material you used, and see if I can hear a difference. I wonder whether some of the perceived benefits of those heavy copper platter mats are actually due to the shielding effect such mats have. If you read the verbal descriptions of the improvements in sonics, it certainly is consistent with the shielding effect. |
Gary, I found on that thread or another DD-related thread that I first wrote about shielding the motor in my L07D, and you asked ME questions at that time. So I assume you proceeded from there, but to find out what exactly I am looking at in your photos, I will seek out the posts you cite. Sadly, the product "TI Shield" seems no longer to be available. One might use mu metal or ERS cloth or just a sheet of copper or stainless or etc. Each has slightly different properties as a shield. |
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... . |
Thanks, Gary. So, basically because your mat is thicker than OEM, the peripheral ring works fine. I looked at your other photos, too. Under the platter I see first what looks like a EMI shield, a brushed silver metallic looking insert that covers everything. What is it made of? Then in some other photos, the brushed silver covering is not present, but instead the parts underneath appear wrapped in some black quilted looking material. What's that? I have a shield between motor and platter on my L07D. Had not considered doing it also for the TT101, but I suppose it makes as much sense. |
Here are some photos - first without the ring, showing that the achromat is thick and allows for the ring: Without Record Here it is with the Jelco 750L (12")and a Zu/Soundsmith/Denon 103 playing a tune: From the top And here you can see it playing from the side: From the side The ring is only about a pound but in conjunction with the center press it is good for slightly warped records and it all sounds very fine. A 1/4" deeper ring could fit as well, the limiting factor is the speed selection buttons. Gary |
I wonder how a perimeter ring could fit. The lip of the platter does not rise much above the surround. It looks cool that way but not very accommodating for a perimeter ring weight. Aigenga, Can you post a photo? Thanks. I pretty near finished up my mods to the QL10 plinth last night. So, at last, I may actually hear a TT101 as Victor intended it, with a Victor UA 9-inch tonearm in the QL10 plinth. I will try to post a photo of the whole enchilada. I also made, or had a machinist make, two extra alu armboards probably to be used for FR64S, Grace G714 (the wood version), or Dynavector DV501. |
Just to add a bit of info to the reversal discussion. My platter (actually two layers: the bottom is a Merrell lead sheet, spray adhesive attached to a thick Acromat-by-Funk hard foam mat) plus the lightest TTWeights perimeter ring and the Michell delrin center press all add up to 3 pounds 1.5 ounces. This is just a bit more than three times the original mat which weighs in at 15.6 ounces. Needless to say, my platter doesn't reverse on stop, nor does it stop. But I see no deterioration from using a substantial bit of weight on top. I have used the combo for quite some time. |
