ALL direct-drive turntables have a "motor controller" of one form or another, built in to the servo circuit. I suppose it is possible that a DD turntable could benefit from a standard AC regenerator, like a PS Audio power source, but such a device is different in purpose from a dedicated tt motor controller. You can assume that the TT101 has such a one. For one thing, the TT101 has a DC motor; the PS inside the chassis converts AC into +/-12VDC and +5VDC outputs. The Denon has a 3-phase AC motor that is "controlled" by a feedback circuit. So, it's able to adjust its speed. (I don't know whether the DP45 has adjustable speed option on the control panel, but the more expensive models in that line-up do/did.) |
Thanks for the great post, Richard. I think of a 3-phase AC synchronous motor is a cousin to a DC motor. In fact, the Victor TT101 does make +/-12VDC in its PS to supply its motor. Likewise, I thought the SP10s used DC motors. But the Denon uses a 3-phase AC motor. Whether or not all of that is correct is not my point or question. What I do wonder about are the "modern" DD turntables, such as the NVS, the Beat, and the new VPI, among others. Their adverts all claim that they've avoided the nasty [sic] effects of a servo by using a 3-phase AC synchronous motor that holds speed by virtue of the mechanism you've just described, sans any servo. At least 2 of those 3 mentioned use fairly massive platters, so it seems to me they are able to give up the servo mechanism by virtue of the mass effect afforded by their platters, much as is the case for some of the better belt-drives. But still, the platter must first slow enough to trigger the speed up commanded by the AC synchronicity. Do you have any thoughts on this?
Thanks. |
"The Beat [like every other direct-drive turntable] has only one moving part, the bearing." The ad copy is correct; however the inference that this quality is exclusive to the Beat is exaggerated, to say the least. But I really really like the Beat. I think it may be the best buy in high end turntables, if $24K is a "buy", but I can live without the hype.
I think I mentioned this above; the Denon DP80 and other models use a genuine 3-phase AC synch motor. But they also built in quartz-referenced servo control. The servo can be defeated on the front panel. It would be interesting to compare its performance with vs without the servo engaged, but you might fairly say that the platter is not massive enough to give the momentum needed for the a non-servo dd to perform really well, even with an AC synch motor.
But isn't the argument that a massive platter and no servo is superior to a lower inertia platter WITH servo just an analog of an old argument among belt-drive aficionados, where the two sides argue over massive platter/weak motor vs lighter platter/torque-y motor? The more things change, the more they stay the same. Massive platters tend to "spread out" any speed error over time. Those who like them say that this is good. Those who don't don't.
And now we have "Mag-drive", because the buying public have been taught for 30 years that direct-drive is a dirty word. |
Dinster, The whole idea of the "Timeline test", so far as it goes, is that it does indeed give you some notion of the instantaneous speed stability, as opposed to average speed accuracy, of a turntable. The time interval measured is akin to the time between laser flashes on your observational starting point. If speed deviates between flashes, such that the flash appears to move in either direction from start, it indicates that in that time interval the speed has deviated, up or down from 33.333. (I don't own a Timeline. I think there are 4 lasers built into it at 90 degree intervals around the pillar, but I could be wrong. 33.333 rpm corresponds to one rotation every ~1.8 seconds. You can figure out the rest.) |
I verbally reported some results I got with my SP10 Mk3, using a Timeline borrowed from my neighbor up the street. (Yes, there are two audio nut jobs living on ONE short block in Bethesda, MD, USA. What are the odds of that?) He was using the Timeline to prove to himself and to me how very unstable was his very high end very expensive belt drive turntable, with a massive platter, I might add. The manufacturer told him there was a fault in his new motor controller to account for his disappointing observations. And now recently the new motor controller and a new kind of belt have been acquired. I don't know what these two upgrades (?) have done to improve his situation. The laser beam was riding around his room so fast I thought we were in a Disco night club.
I've mentioned this before; one problem with the Timeline is that it seems to have been designed for the narrowest of the 3 possible spindle diameters. I found it will not fit on the spindles of my Lenco or my Kenwood L07D (or perhaps it was the Denon DP80). Has anyone else had this issue? Following on the heels of Dertonearm's clever protractor, it would seem that Sutherland could solve this problem by incorporating interchangeable spindle holes, that could screw on to the bottom of the device. Thus, even more vinylphiles could be driven mad. |
Nothing to say except it was bang on accurate, with the laser beam hitting a wall 8 feet away. I did not try a wide variety of music, and I did not persevere for very long once I felt the point was made. Perhaps in 10 minutes of observation there might have been some deviation; I can't say either way. I think I watched the blinking light for 2-3 minutes at most. Then I fell into a "deep sleep" and did whatever my wife told me to do for a week. Eventually, I snapped out of it.
If you're asking whether I can post a video, the answer is that I lacked such a capability at the time, not to mention that I had no such idea, either. I can probably re-borrow the Timeline if inquiring minds want to know. |
Don, While I agree with others that correct instantaneous speed is an important measure of tt performance, it is certainly not the only thing to consider. Different tt's sound different, and it isn't always only due to differences in speed constancy. Yet somehow, I've gravitated to direct-drive and idler-drive (Lenco only); I hear my particular tt's as superior to the belt-drive tt's that I have owned in areas that probably really are related to their capacity to maintain constant speed despite countering forces that exist during LP play, but I've never owned a megabuck belt-drive tt that I might like better. Thus, from my experience, I feel unqualified to generalize. My subjective judgement of what I own and can afford is all that counts, to me. In the end, we're all in that boat. So, I sympathize in part with your view, but the obsession with speed constancy is not just hype. |
I used to think it was "normal" for the pitch of a sustained piano note to waver up and down. (After all, my old AR did the same thing.) I thought it was some issue with the master tape, wow or something like that. Not! |
Dover, My apologies. I probably sounded more indignant than I actually am or was. Perhaps lifting the paragraphs word for word (I knew they sounded familiar) with no attribution is not.... something. But this is the internet, all junk food all the time. |
In agreement with Dover: Not only would one have to adjust the controller for each LP, but one would also have to leap out of one's seat to adjust the controller during highly modulated groove passages and then again when the music has smoothed out. I saw this very phenomenon whilst observing the Timeline on my friend's highly inaccurate belt drive tt (in fairness, later shown to have a malfunctioning motor controller). He had to run up to adjust the controller about every 30 seconds, in an attempt to quell the travel of the laser dot in one direction and then the other, across his listening room.
In disagreement with Dover: It was very unfair of you to indirectly accuse Richard Krebs of plagiarizing Moncrief (who is a scoundrel himself but in other ways). What Moncrief wrote, and what RK wrote, about tt speed as a determinant of musical accuracy, is self-evident to anyone who thinks about it. And RK did not claim to be the first to frame this obvious point. One may as well say that claiming the sun will rise in the morning is stealing from Copernicus (one of Halcro's favorite people).
Further, it's "copyright", not "copywrite". |
Not to beat a dead horse, but if one were to measure precisely the left or right movement of the laser spot over time with no stylus drag and then do the same thing in the presence of stylus drag, one could in fact establish that the tt is capable of maintaining some constant speed in spite of stylus drag, even if that speed was greater or less than 33.33 rpm. |
I would argue with Tony on different grounds. I think you CAN know if drift is due to "speed being something other than 33.33 exactly or if it is changing during play." At least you can know it to the accuracy of the frequency of the laser flashes on the Timeline. (Since I don't have one in my possession, I cannot describe it exactly.) I think it has more than one laser, at least two and maybe four. (Again, "I think" the early version had fewer lasers.) Let's say that the worst case scenario is it has one laser, which means that there will be a flash of light every ~1.8 seconds. Assuming the astuteness of the observer is not a limitation, that means one could detect whether speed has varied during the 1.8 second interval between flashes. If speed is just inaccurate but is not subject to stylus drag, then the drift of the laser spot will be a constant amount in one direction or the other. (Halcro just gave an example of that with the Raven.) If speed is being now and then momentarily retarded due to stylus drag (or other cause), then the laser spot movement will be irregular or regularly irregular or irregularly regular, within the limits of detection determined by the frequency of the laser flashes, which would be every 1.8 seconds divided by the number of lasers flashing per revolution. |
But Syntax, is the Kuzma constantly too fast by a fixed amount while playing LPs, that is, regardless of stylus drag? If so, that is a fault remediable by an appropriate motor controller and not a black mark against the Kuzma.
Tony, I just cannot agree that a tachometer, no matter how good, is potentially superior to the Timeline for detecting micro-variations in speed, unless it would run off the rotation of the platter by a direct and perfectly non-compliant mechanical linkage, with no "belt creep". And then you'd have to stand there and watch it or run a recorder off of its output. In fact, Denon produced such a figure for use in their ad copy for the DP80; they show a very low level wiggle in an otherwise straight line, representing 33.33 rpm on the Y-axis, with time on the X-axis. But I doubt that the data come from a tach read-out. I don't recall how they derived it.
Peter and Henry, So if the single laser flashes six times per revolution, that would be about every 0.3 seconds. That's pretty near an instantaneous read-out. I wonder how it compares to the response time of a very good servo correction system. Maybe Richard knows. |
Tony and Brf, I hate to be wrong, but I see your point(s). I saw Brf's point in my own mind, shortly after my last post. Most servo-controlled DD turntables have some sort of platter speed sensor, optical or otherwise. One could probably tap into the output of that data stream to get a continuous read-out of speed stability. That may be what Denon did in order to produce the figure shown in their ad copy for the DP80, which I described above.
Henry, I don't think Syntax's post about the Kuzma was so provocative. As I noted, the fact that the Kuzma was a little fast (or slow; I cannot recall) is not so important as whether it was stable in speed, because a decent motor controller could probably bring it back to exact constant speed, if the error was also constant. But he never responded to my question in that regard. I am not a "Kuzma guy", but I would imagine they have a recommended motor controller for their better models, such as the Reference. |
Tony, According to others, the laser flashes 6 times per revolution. That means you can get a read-out every 0.3 seconds. So you are indeed "averaging" the speed, but it is over a very small increment of time. Your talk of a "tachometer" is specious. Tell me what you have in mind more precisely, because when you use that term I envision a device that must be mechanically linked to the platter. Any such device will be subject to errors caused by tolerances in the mechanical linkage. There is always slop in any mechanical linkage. Also, any mechanical linkage cannot help but also have an effect on the performance of the turntable, the Heisenberg principle. If you chop up time into increasingly tiny aliquots, you approach a continuous read-out. By the same token, the readout can never be truly "instantaneous", nor can that of a tachometer. The Timeline does not get there either, but it gets very close. Which is why I asked aloud about the time required for servo responses in a high quality dd turntable. The comparison to a car computer is pointless, not a good analogy at all, IMO.
The odd thing is that I don't own a Timeline and never plan to own one. I choose my tt's based on how they sound and if they can hold speed with a KAB strobe. If the "33" on the strobe disc does not wiggle, much less move at all, I am happy enough. Then I listen. |
Dear Thuchan,
In principle, it might not be a good idea to mount motor, table, and flywheel on separate isolation platforms. Unless you also stipulate that said platforms should be identical in all respects and mounted on a common shelf. The issue is that if the respective platforms resonate at different frequencies, and/or if they are differentially isolated from environmental energy, then there is a risk that the motor and tt will move relative to each other. That allows tension or relaxation of the belt, alternately; not good for speed stability.
Why do you dislike threads vs "belts"? For a belt, do you recommend compliant or noncompliant? Thanks. |
Don, You (sadly) wrote:
"I am not a fan of servo controlled speed. The speed is wrong a lot of the time!
A properly designed turntable should run at a constant speed!
If there is stylus drag (that audibly effects sonics) , then increase the speed slightly." (DUH!!)
That is more of a rant than a rational statement. It reflects your complete misunderstanding of the problems associated with maintaining constant platter speed despite frictional forces (stylus drag) that are constantly changing in magnitude. I take it your experience with direct-drive turntables, if you've had any, has been a negative one. In reaction, you are creating a hypothesis based on no data and a paucity of knowledge. You may fairly say that you dislike this or that direct-drive turntable, but do not presume that your subjective opinions are necessarily applicable to all such turntables. Nor do you have any data that would lead you to understand why you did not like whatever you've heard.
About the SDS (and similar motor contollers) I agree with you. Any belt-drive tt motor that does not have a built-in motor controller circuit of some sort will benefit greatly from the addition of a motor controller designed to maximize the performance of the particular motor type. For example, a 3-phase AC motor is quite a different animal from the induction type motors used on early Garrards and Lenco. The SDS (and the Walker Audio Precision Motor Controller) work on a wide variety of motor types, but for the same reason neither is optimized for any one type.
Someone else brought this up, and it puzzles me too: Why the heck does the Timeline laser flash 8 (or 6) times per revolution, when we are only observing a single flashpoint at a time? What is the advantage? I had hoped incorrectly that the "extra" flash events were used to enhance the sensitivity of the instrument. (As I stated, if 6 flashes could be used to cut down the time interval between observations from about 1.8 sec to 0.3 sec, then the sensitivity begins to approach that of a continuous read-out, to make Tony more happy with it. But as others, including Tony, point out, this is not happening.)
Since the mass of the Timeline is concentrated over the bearing, giving the motor lots of mechanical advantage in moving it, and since the Timeline that I had use of is very reasonable in mass, less in fact than many record weights, it's hard to imagine that its mass would alter the results detectably. If the motor cannot handle THAT much drag, it probably cannot handle stylus drag either. |
Tony, From your description, it seems you have an older SOTA tt. So far as I know, all the later SOTA tt's have eliminated the very real problems inherent to a belt-drive design that mounts the motor on the chassis while suspending the platter and bearing. (You've described them well.) You might consult SOTA and let them "fix" it or let them tell you how to do it.
In the 90s, I lived for many years with a Star Sapphire Series III, which is built their "old fashioned" way, with motor mounted to chassis. I thought during that time that it sounded "pretty good", but I was not yet a total analog nut job, as I am now. Words cannot express how much better analog can get compared to what that SOTA SSIII gave me, in retrospect. Even my next tt, the Notts Hyperspace, with its stretchy rubber belt and weak motor, just absolutely killed the old SOTA in terms of pitch stability. The Lenco and all of my dd tt's take that to yet another dimension, adding more drive and open-ness to the music. You've gotta try it. Timeline, Shmineline. |
I think that back in the day, a few tweakers used to disable the suspension on SOTA tt's entirely and then mount them on any of many various isolation platforms. In other words, turn a suspended tt into an unsuspended one. Let the platform do the work. |
Dear Dover, From my perch, I view the dynamic as follows: Halcro is perhaps guilty of trying to "prove" empirically the superiority of his TT101 (and maybe now the TT81), while you seem to be trying to prove the superiority of belt-drive, at least as represented by your Final Audio Parthenon (which may be one of the best of that breed). (Your puncture wound of Halcro's logic re the Raven is perhaps valid, by the way.) Your both entitled to your opinions, and both opinions are equally valid, IMO. I guess I side with you, however, on the subjectivist side; I will check the speed stability of any tt with the KAB strobe device. If speed is stable with LP in play, that's good enough speed stability for me. Then comes listening, and listening trumps other considerations.
As to your preference for the FAP vs the L07D and MK3, have you heard both of the latter in your current system with same tonearms and cartridges, so as to validate your opinion? If not (and I think not, given that the L07D has its own tonearm, for one example), then your opinion of the relative merits is just your opinion. Which is fine. |
But when the Micro is auto-correcting, it is doing so via a mechanical system that has lots more compliance built into it (the belt) compared to any direct-drive system. Thus there is more danger that the corrective action will lag behind the moment of the occurrence of the speed inaccuracy, leading to over-correction, and thus actually contributing to the problem, rather than to ameliorate it. I don't know that this is connected to the fact that others who revere MS tt's have remarked that they do not use the OEM MS motor, preferring other motors instead. |
Sorry, Henry. I may have failed to be clear about my opinion on the Timeline vs the KAB. I agree that the former is probably a more demanding standard than the latter. What I meant to say is that when the KAB is "happy", I tend to be happy too, meaning the KAB standard seems to be good enough for me.
Interesting thing happened last weekend. I invited my audiophile neighbor over to my house to listen to the Beveridge speakers I have set up as a second system in my basement. The source was my highly modified Lenco tt (slate plinth, Jeremy Superbearing, Speed dialed in from Walker Audio Precision Motor Controller). When in the course of our listening I played a 45 rpm LP, by switching the Walker from 33 to 45, he remarked that he is cursed with perfect pitch and that the Lenco sounded a tad slow on 45. We checked his judgement using the KAB strobe, with and without the stylus drag. The KAB showed without doubt that the Lenco was in fact running a tad FAST, not slow, at 45. But the speed was "constant", in that the "45" viewed via the strobe, was not wiggling back and forth, but drifting slowly in the direction that indicates overspeed. Anyway, we live and learn. (This guy owns the Timeline that I have been able to borrow on the odd occasion. His own expensive belt-drive tt is revealed by his own Timeline to be wildly variable in speed. The maker is replacing his motor controller and belt in hopes of curing the problem.) |
Dkarmeli, If the KAB locks in at slightly LOWER than correct speed, as you say above, that means my Lenco was running even faster than the KAB revealed it to be, because, as noted, the KAB indicated overspeed, not underspeed. Which means my friend's sense of pitch is not as perfect as he may have thought, since he perceived the tt speed to be slightly "slow". The whole anecdote was noted just to poke fun at ourselves as a group, and the idea that we can perceive tiny errors in tt speed.
It's possible that there would be some minor variation in the performance of the KAB strobe, if there is some minor variation in whatever hardware is used in the strobe to induce it to flash with some exact frequency. Given the nature of such ICs, I would posit that the error there is very tiny, indeed. |
Ack, I follow your reasoning right up to the last sentence. The Timeline per se is not even as heavy as the "typical" record weight, and the mass of a record weight/Timeline is concentrated at the center of rotation, where the motive force has a tremendous mechanical advantage, compared to the mechanics of overcoming friction forces applied at the outside edge of an LP via the stylus. Any tt that would be appreciably slowed by the Timeline would be one that is very prone to any effect of stylus drag, as well.
Plus, I may be wrong, but I do think Halcro did the proper control in this case. He will tell us. |
Dear Richard, If anything, the tt itself generates RFI internally. I think Halcro noticed some related issues when he ran his "naked", without the metal casing. In fact, I think we all concluded that one function of that casing is to shield other components from RFI. But how could extraneous RFI account for my problem? (By the way, I do use the AM radio as an RFI detector. Moreover, my TT101 malfunctions exactly the same in our kitchen on the first floor as it does in the basement, which I should think is a much more inherently protected environment, because it's all below ground.) I don't say you cannot be correct; I just wonder why and how. Your further thoughts are welcome. |
The big question is, what's a "turnable"?
Here we've all been talking about turntables, and Halcro wanted to discuss turnables all along.
Some few of you might want to know that after sending off my own TT101 for its third fix, the repair person (NOT Bill Thalmann; I could not bear to tell Bill that his fixes don't work at my house even though the TT101 works flawlessly in his shop) reports to me that in HIS shop, my TT101 also worked flawlessly, for weeks on end. He cannot make it malfunction, so he cannot fix it. He is sending it back to me. Gremlins afoot, no doubt. I am keeping my fingers crossed that it will decide to work for me when I do receive it. |
Yeah, I thought of that. This last guy made about $150 and can freely admit he's done nothing. Yet I still have to pay for his time. What a country!
However, in Bill's case, not only is he the salt of the earth in terms of honesty, but I did see my TT101 work in his shop. We played with it for about 15 minutes, turning it off and on, changing speeds, etc, and observed no issues.
Interestingly, I asked this last guy (whom I have never met in person) about lubricating the bearing. He virtually laughed at me, said they were made to last forever. He wouldn't even think of taking the bearing assembly apart. When I pointed out that Victor probably did not contemplate that anyone would be using the TT more than 30 years after its build date and so could not have envisioned that much life span for the bearing, I was dismissed. Just as well. I'd rather do it myself, or not. |
FWIW, my unit has all new electrolytics. That's the first thing we did during the first round at Bill's shop. On the second go-round, Bill re-soldered all those suspect solder joints. When it then failed in my house, I myself re-soldered yet more of the connections, to no avail. (There wasn't much left to do; Bill was very thorough.) To Richard's question: there are no obvious sources of RFI in my basement in my suburban residential neighborhood. Maybe we missed something as regards solder joints, because transport seems to be associated with the problem's elusive nature, suggesting that shipping trauma can rattle some connection that is tenuous. Hence, I will give it a good swift kick as soon as I get it back home. That should do 'er some good. |
Halcro, Did you not report earlier some issues related to removal of the outer cage? Either this had a bad effect on the tt itself or on some nearby components. And Richard, since we had concluded rightly or wrongly that the outer cage is an RF shield, why would you have no doubt that the TT's work better without them? I would say it's a toss-up, without knowing the real why of the cage, other than to provide physical protection for the working bits inside. The motor is a well enclosed unique and separate structure, by the way. Possibly its radiation is shielded from the circuitry thusly, even without the cage in place.
I will receive my TT101 tomorrow. If it malfunctions, I will try removing the cage. If that does not work, I will kick it. |
OK. When I finally got home at 9:30 tonight, there was a big box sitting outside my front door, left there by UPS. Apparently my dear wife had not even peeked outside all day, or at least since late afternoon. As you may have already guessed, my prodigal TT101 was inside said box. I just now unpacked it, and guess what. The SOB is working fine here in my kitchen. I am not going to breathe on it.
Apparently the TT101 is a lot more complex than the TT81, thanks to the unique reverse servo mechanism in the TT101. Thus I have no doubt that the TT81 would be less problematic. But nooooooo; I had to have the "best". Serves me right.
Should I run and borrow that Timeline from my neighbor, while the TT101 is working right? The tach is set in the mode where it counts repeatedly up from zero to set speed, over and over again. I prefer it in steady state mode, where it reads the speed with no re-cycling, but am I going to flip the switch that changes the mode? Not on your life. That may have something to do with this fragile triumph. |
Every time I pass through the kitchen, I fire up the TT101 once or twice to see if it's decided to go nuts again. This morning it finally did, once, from "cold" (power off overnight). Then it worked again on re-start for the duration of my light breakfast. I think the two technicians who have worked on this thing have simply left it running for days on end in their respective shops and therefore have concluded that they cannot duplicate my problem. The failure mode occurs at start-up, or not, so once it gets up and running it does seem to be fine. Perhaps the best approach is to leave power ON at all times or at least to wait a bit before starting the motor up after having applied power. And the failure mode is the same: If the tach displays "33.34", it's going to die within seconds, no braking, tach goes blank except for the decimal point. Bill Thalmann told me that the circuit is slaved to the tach, I think. Something in the circuit does not like to see overspeed, which makes me think the issue resides in the reverse servo mechanism.
But on the other hand, as regards Power, the thing malfunctioned consistently, every time no matter what, cold or warm, within about 90 seconds after start-up, before I sent the unit out this last time. So there goes my hypothesis. Yep, Gremlins in the basement. |
Well, what I have is a huge improvement compared to the way the TT101 was behaving before I sent it off to New Jersey. It does work fine about 90% of the time, and if it prematurely terminates, it seems to need only a re-start to get it up and running properly again. I feel confident enough to use it now, whereas it was a complete dud before shipping back and forth to NJ. Here's to UPS; they know how to kick around a turntable so as to improve it. (The repair guy in NJ candidly admits he did nothing; it would not even malfunction for him.)
The problem has got to be some micro-fracture in the soldering, as someone else suggested. Since I have 4 other perfectly good tt's, I do have time to go in there again and just re-solder everything in sight that has not already been re-soldered. |
Hiho,
Simple answer: I have not yet listened to the TT101, ever! Mine came as part of a QL10 (TT101 + Victor laminated wood plinth + Victor 7045 tonearm). The ensemble is in "like new" condition. I expect to listen to the TT101, at first, in this context. An assessment of the QL10 plinth, at first glance, is that it is "adequate". A big weak point, IMO, is the armboard, which is laminated wood and not terribly dead. My first goal would be to replace the armboard with one made of either Alu or brass. I just looked up the cost of the brass... more than $100 for a slab that would then need to be machined. So, perhaps alu will do for now. I have a piece already suited to it.
So last night I installed the TT101 motor into the QL10 plinth. For my personal preference, I re-set the tach to read out in "Hold" mode, rather than "Run" mode. In Hold, it reads out the steady state speed. In Run, it re-zeros itself every few seconds and then runs itself up to actual speed, over and over again. Interestingly, I got it back from the last repair guy in Run mode; I had never used it in Run mode prior to now.
When re-set in Hold mode, my unit malfunctions exactly as it did when I sent it off last time: it gets up to speed and holds it for about 90 seconds. Then it starts to show a very tiny speed error, e.g., 33.32 or 33.34, instead of 33.33. That event is premonitory to total shutdown. The tach goes blank and the "off" light goes on. The platter coasts to a stop with no brake effect. I initially blamed the recurrence of the old problem to the fact that I had had to tighten the tiny screws that hold the big metal outer chassis cover onto the lower motor assembly, in order to fit the TT101 into its plinth; otherwise the screws foul the wooden rim around the opening for the TT. I had previously observed that the unit works "better" when those screws are loose. I was about to take the TT101 out of its plinth again, to remove those damned screws entirely and leave the cage loose, but I had another thought at the last moment to see how the TT would work if I re-set the tach mode to Run. Sure enough, the table has been working beautifully and consistently all day long, on either 33 or 45 setting. This is consistent with Bill Thalmann's remark that the servos are slaved to the tach read-out. Also, I note that when the TT101 is working really well, as today, the platter comes to a complete halt immediately when you press Stop. This suggests that both the forward and reverse servos are doing their jobs. (There is no mechanical brake, to those who do not own one of these beasts, unlike in the Technics and other tt's.) When it is failing, and if I depress Stop before the failure mode kicks in, the platter will drift counter-clockwise for about one revolution and THEN stop, again pointing to the reverse servo as a culprit. It's all well and good to analye the problem, but finding the glitch and fixing it is a daunting task. I will leave mine alone as long as it works in Run mode.
This must be boring as watching paint dry, to anyone who does not own a TT101. Sorry. And I guess it's OT as well, but Halcro owns a TT101, so maybe he does not mind. The moral of the story is if you own a TT101, it is best to own at least one other reliable tt. |
Richard, So many of my "conclusions" as regards what the hell is going on with the TT101 eventually prove themselves to be false or only half true, that I am loathe to make any pronouncements, but I do see with my unit that keeping it powered on all day yesterday was a good thing to have done. And in fact it started the day from "cold", malfunctioning with the tach in Hold position. It was warmed up when I switched into Run mode. One might argue that had I switched back from Run to Hold later, after it was warmed up, it might have worked fine. Thus my conclusion above that my unit works correctly only in the Run mode could be incorrect. Frankly, I don't care, so long as it does work.
Now you are going to make me run home tonight and turn on all my DD tt's. They have been sitting idle for quite some time, because I have been using only the Lenco on the Beveridge speaker system. There's no room to set up a second tt anywhere near the preamp. |
TT81 for others, maybe. I've got DP80, L07D, SP10 Mk3, Lenco for "back-up".
TT101 is looking good. I am leaving it power up. Your quite right that the innards are a veritable rat's nest. I have observed that it is difficult to pack all the wiring back into the metal canister, after working on the circuit. In particular, the AC cord has to be folded just so, otherwise it won't fit. Plus there are all those interconnecting wire harnesses. My hypothesis is that the workers who built these things knew precisely how to lay out everything for final assembly. Then, after 30 years of aging of solder joints and PCB traces, we come along and take the tt's apart and cram them back together when work is done. It is my observation that incorrect routing of the wiring harnesses and AC cord followed by "cramming" can cause the various PCBs to bend a bit, thus putting stress on solder joints and tracings. I would bet this has a lot to do with our problems. |
"Your" = "You're", of course. I hate when I do that.
Henry, Can you make me one of those free-standing cradles for my TT101? Who makes your arm pods, etc? Based on your first hand inspection, do you perceive that the TT101 and the TT81 have exactly the same motor? It looks from photos that the TT101 motor might be different in size or in some other way from that of the TT81. I know they are both coreless types.
Hiho, I can see the light at the end of the tunnel, as regards a report on how the QL10 ensemble "sounds". I am dealing with some amplifier problems that appear to have been resolved. One amplifier for each of my two entirely separate audio systems has been "down" on my workbench. |
Yep. I guess my posts on the vicissitudes of the TT101 belong in the "Living Dangerously" thread. |
On topic: The well seems to have gone dry as regards posting of Timeline results on this thread. Given the many months of its existence, one would have thought there would be more videos by now. When I finalize the modifications I am making to the QL10 plinth and arm board, and then put the QL10 back into operation, I will test my own TT101, see if can do what Halcro's did. |
Hiho,
Nice research. Somehow, somewhere I came away with the belief that at least the TT81 motor is coreless. Don't know anything about TT71. But I agree with you that the photo seen when I click on "picture" does suggest that the motor has visible poles, therefore not coreless. Moreover, in the exploded views you reference, it appears that the TT71 and 81 motors are more cannister-shaped, whereas TT101 motor is wider and flatter, consistent with Dual-like coreless design. Anyway, Halcro will chime in, I'm sure.
I think I had trouble Timeline-ing my SP10 Mk3, because of a misfit between its spindle and the female receptor for the spindle on the Timeline. That's when I posted that Sutherland ought to offer interchangeable spindle holes, for his $450 price. The Timeline definitely does not fit my Lenco spindle. Maybe THAT was the problem I had, not with the Mk3. |
