I was thinking to move this thread to the "Tech talk" section. Is this a good idea? If so, please feel free to do it.
Thanks,
Sébastien
Thanks,
Sébastien
Technics SP-10 mkII speed adjustment question
Hi,
I'm on my way to complete my Technics SP-10 mkII project. Actually, a friend of mine, a professionnal audio technician, is working to upgrade the PSU, which is done but a small adjustment on the speed must be done and he need some cue on this issue.
We already asked Bill Thalmann, Artisan Fidelity and Oswald Mill audio. Plus, I'll post on DIY Audio today. We'd like to get the answer as quickly as possible to finalized this for the week-end. Hope someone on Audiogon can help.
Here's the message from my technician:
"Hello,
I'm an electronic technician and I do repair for audio equipments, vintage, hifi pro and more. I have a client here that brought me his turntable Technics Sp-10 MKII to fixed. I have a little question about it and he gave me your email because he pretended that you have some experience with this kind of materiel. So, hope that you can response my technical question.
I replaced all capacitors in the power supply and a big solder job. I checked for defect solders or capacitors on the circuit boards inside the turntable and I tied to do the adjustments . Everything seem good right now, the turntable work fine. I tried do do the period adjustment with the VR101 and VR102 potentiometers like in the service manual ( see attachment, Period adjustment method). When I looked the stroboscope at the front of the turntable, It's pretty stable but I can see a tiny rumble at 33 1/2 and 78 speed. 45 is the more stable speed for the stroboscope. So, I fixed the phase reference with T1 at 18us of period and I try to do the period adjustment at the point test T and S on the board with the O point for reference. When I put my scope probe on the T point, I can observe the stroboscope running. It is not stable at all. If I pull off my probe, the stroboscope is stable again. So When I have the 2 probes at point S an T at the same time to do the adjustment, it's impossible to fixed the wave T because it going right to the left on my scope. When I turned the VR101, the T wave going faster or slower but never stable. I tried to ground lift my scope, plug it into the same power bar and try to pull off the reference at the O point. I can't have a setup that I can see a stable T wave in my scope with the one that I can do the right adjustment. Why? Is there a problem with the turntable or maybe it's a incorrect probe or ground setup? Please let me know what you think.
Best regards"
Thanks for help,
Sébastien
I'm on my way to complete my Technics SP-10 mkII project. Actually, a friend of mine, a professionnal audio technician, is working to upgrade the PSU, which is done but a small adjustment on the speed must be done and he need some cue on this issue.
We already asked Bill Thalmann, Artisan Fidelity and Oswald Mill audio. Plus, I'll post on DIY Audio today. We'd like to get the answer as quickly as possible to finalized this for the week-end. Hope someone on Audiogon can help.
Here's the message from my technician:
"Hello,
I'm an electronic technician and I do repair for audio equipments, vintage, hifi pro and more. I have a client here that brought me his turntable Technics Sp-10 MKII to fixed. I have a little question about it and he gave me your email because he pretended that you have some experience with this kind of materiel. So, hope that you can response my technical question.
I replaced all capacitors in the power supply and a big solder job. I checked for defect solders or capacitors on the circuit boards inside the turntable and I tied to do the adjustments . Everything seem good right now, the turntable work fine. I tried do do the period adjustment with the VR101 and VR102 potentiometers like in the service manual ( see attachment, Period adjustment method). When I looked the stroboscope at the front of the turntable, It's pretty stable but I can see a tiny rumble at 33 1/2 and 78 speed. 45 is the more stable speed for the stroboscope. So, I fixed the phase reference with T1 at 18us of period and I try to do the period adjustment at the point test T and S on the board with the O point for reference. When I put my scope probe on the T point, I can observe the stroboscope running. It is not stable at all. If I pull off my probe, the stroboscope is stable again. So When I have the 2 probes at point S an T at the same time to do the adjustment, it's impossible to fixed the wave T because it going right to the left on my scope. When I turned the VR101, the T wave going faster or slower but never stable. I tried to ground lift my scope, plug it into the same power bar and try to pull off the reference at the O point. I can't have a setup that I can see a stable T wave in my scope with the one that I can do the right adjustment. Why? Is there a problem with the turntable or maybe it's a incorrect probe or ground setup? Please let me know what you think.
Best regards"
Thanks for help,
Sébastien
144 responses Add your response
You really do need to take this to a more tech-oriented site. But one comment I have is that there are a large number of electrolytic capacitors on board the main chassis, and they are not exempt from failure or faulty operation. If the caps on the main chassis board are still the OEM ones, I recommend replacing them empirically. Then maybe start over with these measurements. Also, if you have a connection with Bill Thalmann, he can probably help your guy over the phone, if indeed the problem persists once all the remaining lytics are replaced. I am not at all surprised that neither OMA nor Artisan could help; those guys are not techies. |
Regarding the comment from Lewm- "I am not at all surprised that neither OMA nor Artisan could help; those guys are not techies." OMA does not provide free technical advice. We employ several technicians. They do not work for free. I explained that to the OP. Considering that OMA has created a completely original, ground up motor control for our Tourmaline turntable that uses the SP10 motor, and that does not use PLL or DC, your comments are laughable. Jonathan Weiss OMA |
Then you are free to laugh. First you say that you do not provide free technical advice, and then you brag about your technical expertise, which you will not provide to the OP, because you "employ several technicians" who "do not work for free". So in the final analysis, and as regards the chances for the OP to get some help from you or your company, where was my error? The OP states that he contacted you and that you could not help (his words). I take his statement at face value. So why are you laughing? |
For a government research scientist, Richard, you don't seem to understand much. My company employs technicians- in other words we pay them. They do not work for free. We do not provide free assistance to other technicians who cannot figure out a problem. Guess you did not understand the part about OMA creating a completely new motor control for the SP10, either. But then again, we're not "techies." Too funny. Jonathan Weiss OMA |
Who is Richard? In any case, the point is that you do have technical capability (or rather, your company does) but that you will not supply it to the OP free of charge. Since you are in the audio business, this is perfectly understandable. I'm still not sure why it's "too funny". Kudos to you on your de novo motor controller. Do you also repair defective SP10s? If so, I gather you would work on the OP's unit, if he were to send it to you. Excellent. Obviously you are a techie, and I was in error. |
We also do not provide free technical service but referred the OP to a certified technician we recommend in Chicago for advice. Our certified technicians are not available for free technical advice or assistance. In the event the OP should decide to send in his Mk2 for service, we would obviously be able to repair/service his unit accordingly. Christopher Artisan Fidelity |
Hi Lewm, You were right. I think that Audiogon is not the more technicaly oriented site. Let me tell you that DIY Audio surprised me because I don't have any answer there. Then, about some email I send to companies, M. Weiss explain the answer he gave me by his personnal email to me. With the search I've done I was looking for: 1) get an answer from the community; 2) get an answer from a company with a sense of community in it. The winner is M. Bill Thalmann. He answered to my audio technician with professionnalism and a great sense of share. In the end, like an old university teacher once said "We don't teach what we know. We teach who we are." I know that there is still a great sense of community left in our hobby and passion. Have a good day, Sébastien |
Sebastien, I am very glad to hear that you got help from Bill. I feel very fortunate that I can get to his shop from my house in only about 30 minutes, and once I get there, I know absolutely that my equipment is in the best possible place for repair. I was rather surprised, actually, when you inferred in your first post that Bill was unable or unwilling to help you; on both counts, I would have expected him to come through for you. Glad to know that this is indeed the case. Christopher, as I also remarked to Jonathan, I think your position is entirely understandable. I meant no slur on either of you, when I wrote that your respective companies were not "techies". What I really meant by that is that you are not primarily in the business of repair or of offering highly specific technical advice over the phone. If I was wrong even on that level, thanks for the correction. |
Hi Lewm, I think that I wasn't clear in my first post when I said: "We already asked Bill Thalmann, Artisan Fidelity and Oswald Mill audio..." I meaned that we had contacted them, but at that time, we haven't received any answer from them. Finally, I learned that Bill already contact my technician who emailed him before me. Just a bit of confusion there. Sébastien |
Sounds like when your guy looks at the strobe, the act of doing it loads the circuit enough that its unstable. Most 'scopes have a high impedance input (10M is typical) so the loading should not be an issue; this suggests that a device very close to the test point has failed and is barely able to pass the strobe signal. |
Sebastien, The mat in my system picture is the Boston Mat ll. As Lewm states, it sounds great on that table. I also have the SAEC SS300 and like it a lot. I can't really pick a favorite on this one but they both are a better weight for the mkll than the Micro Seiki Cu180 IMO. The SAEC is out of production and may be a little tricky to find. The Boston is in production and affordable. |
Hi Sonofjim, I was considering the Micro-Seiki CU-180 seriously and someone just offered me one today at a fair price. Could you explain me more about the "better weight for the mkII" when you compare the Boston mat to the Micro-Seiki? I have read many comments regarding the good match between the Micro-Seiki CU-180 and the SP-10 mkII. The latest seems to have enough torque for the heavy Micro-Seiki copper mat. Well, I'll be glad to know your opinion on that subject. Sébastien |
IMO the cu-180 is way better than the Boston Audio mat1 in my system. The Boston mat is good but the cu-180 blocks EMI coming from the motor. Also IMO it is not too heavy for the SP-10 mk2. In fact the extra weight may be a benefit. I think it smooths out the speed a little. The cu-180 definitely lowers the noise floor compared to the Boston mat. Sonofjim, Have you tried the cu-180 in your system? If you had I would be surprised if you did not like it. |
If EMI is a real problem, one could also make a shield expressly to treat that problem; the shield can be placed under one's mat of choice. I did exactly that for my Kenwood L07D, which uses a stainless steel platter mat, which you would think is by itself a decent shield. Nevertheless the L07D sound was improved by using TI Shield (a Texas Instruments product). I bought one square foot and cut it in the shape of an LP so it fits under the SS mat. Works very well. What is the weight of the cu180? This is an old and pointless debate, but using a much heavier than stock platter mat in theory is not a good thing for a servo-controlled direct-drive, where the system was designed to cope with a certain inertial mass. Note, I say "in theory". I realize there are practical exceptions. And actually I think the cu180 is within shouting distance of the weight of the standard mat, about the same as the SAEC SS300, which I know does no harm on the Mk2. Not as crazy as some of those very much heavier TT Weights mats. |
Lewm, The cu-180 is 4 lbs. I had the same concerns about too much weight affecting the servo in a negative way. In practice this is simply not the case. If anything it's affecting it in a positive way. I had some TI Sheild that I put under my Boston mat. TI Sheild is very springy stuff. If it's not perfectly flat it will not lie flat unless you have a heavy enough weight on top. The Boston mat is not heavy enough. A heavier mat negates any weight saving advantage. It is conceivable someone could get it flat enough to work but it's very difficult. I ruined the TI Sheild I had messing with it. I could get some more and try it under my cu-180 and see if there is any improvement. Will your stainless steel mat from your Kenwood fit on your SP-10 mk3? That would be an interesting experiment. I believe Albert Porter is using a SS mat on his mk3. |
As I said above, I am considering the Micro-Seiki CU-180 mat from a seller who's serious and from whom I already bought. The seller tell me that the mat is brand new and was made in 2011. I'm a little bit surprised because I was sure that Micro-Seiki was not in the business anymore and this mat not in production for already few years. Is there some of you that can confirm the time that the production of the CU-180 ended? Thanks, Sébastien |
Dear Sarcher, If the CU180 weighs 4 lbs, I personally would to use it on a Mk2, as the stock mat weighs only about one lb. The whole platter weighs ca 8 lbs, I think. So by using the CU180, you increase the inertial mass by nearly 50%. But this is all theory, and if it sounds great, just ignore me. Since the Kenwood L07D stainless steel mat weighs 5 lbs, you can bet that it flattens out the TI Shield "real good", to quote Big Jim McBob from SCTV. Flat as a pancake; you cannot even see it's there, because I cut it to be very slightly smaller in diameter than the ss mat. I hadn't thought about that issue you bring up in relation to using it with a lightweight mat. Further, the TI Shield has to be grounded in order to work as a shield; I am not sure it would be grounded if used under a non-conductive mat, like the Boston Audio products. Maybe so if the platter itself is bare metal, i.e., not painted or coated with something that insulates. Albert is lately using the Boston Audio Mat2, on his Mk3. As mentioned above, I use the Mat2 as well on my own Mk3. We arrived at the same place coincidentally. I like the Mat2 a tad better than the SAEC SS300. By the same token, I would be reluctant to use the Kenwood mat on my MK3, because it weighs 5X the OEM rubber mat. I got this notion about not violating the inertial mass of the stock design from, of course, something I read on the web. I have always meant to check it out with Bill Thalmann, who has worked on both my Mk2 and Mk3, but it does make sense. |
Well, I'm not going to commit myself for the purchase of the CU-180 mat for the moment. It looks like this seller, even with many positives feed-back regarding other items, have already sold two counterfeit CU-180 mat to Audiogon member. By the way, I still consider the Boston mat 1 or there's the option to look for another CU-180 at a good price. Sébastien |
Sebastien, Sarcher, Yes I have tried the CU-180 with the mkll and did like the sound. I have two CU-180s and currently use each on custom MKlll tables. I thought the mkll sounded more dynamic and alive with the Boston mat ll, which BTW is an upgrade from the mat l, and the SAEC SS-300. The SAEC is actually closer in weight to the Mat ll than the CU-180 which does weigh 4 lbs(essentially what a TT weights mat weighs). Both the SAEC and Boston mats are closer to the original mat weight. I prefer the CU-180 on the mklll with it's considerably greater torque. The Boston is affordable and sounds great, no worry about counterfeiting. The SAEC I believe was made with the MKlll in mind and is Steve Dobbins recommendation. Believe it or not, even though I have the SAEC I haven't yet gotten around to trying it on a MKlll as of yet. |
Dear Sonofjim, I went from an SAEC SS300 to the Boston Audio Mat2 on my Mk3. Both are good, but I do slightly prefer the BA. Both are far superior to the factory rubber mat, for sure. I could envision that with certain tonearm/cartridges, the SAEC might be preferable to the Mat2. Don't know for sure. |
Sonofjim, Thanks for your input. I have changed back and forth a couple of times between the cu-180 and BA-1 and still prefer the cu-180. Maybe I should try the BA-2 one of these days. Lewm and Sonofjim, Do either of you guys plan on having Bill Thalmann do the latest mods on your MK3 like Albert Porter has recently done? I wonder if Albert has changed his prefence of mats after the mods were completed. Sean |
Sarcher and Pryso, Albert is ecstatic about the new modifications, but he really did not know much about what was done. I then talked to Bill about it. Mostly it is about dampening vibrations and firming up the stator supports. Bill notes that as the servo system corrects for speed errors, some of the energy of the motor is used up in micro movements of the stators, predicted by Newton's Third Law (For every action, etc...) (Ideally, all motor energy would go into moving the rotor/platter.) These tiny wiggles of the stator then in turn produce a tiny correction error sensed by the servo, which senses the fact that some of the torque went into moving the stators instead of the platter. This begets another correction from the servo. And so on. With the modification to the stator mounts, there is less energy dissipated in moving the stators, more precise speed correction by the servo, and far fewer events that trigger the servo. Everything gets even smoother than it was. There is also some work done inside the PS, about which I know nothing. Anyway, Albert likes. I will get it done, but the cost is $1200, so I am waiting a bit before I can commit those bucks. |
Lew, thanks as always for your info. Not to start another war here but Bill's comments on the need to dampen vibrations seems to fly in the face of the advocates for "plinthless" installations touted in a different Audiogon Analog posting. ;^) That makes me wonder, have you ever ask Thalmann his perspective on plinthless DD installations? Yes, that might be a redundant question. |
Regarding my first post of this thread, I must inform you guys that the upgrades for the PSU have been done and the speed adjustment of the SP-10 mkII also. Thanks to Bill Thalmann for his help. Now everything is in order and the speed is chirurgicaly spot on, like my technician said. Plus, I assembled the turnatable in an Albert Porter panzerholz plinth last Friday, also installed the SME 312S, the Denon DL-103R. I'm still looking for a new mat and waiting for 4 Stillpoints cones and risers to complete it all. If I tell that I was moving from a Rega P3 to this set-up, you will imagine that is a completely other world of music reproduction and it is. Sébastien |
Tim, It goes to what we talked about in the plinth thread. IMO, you need some way to appose the tendency for the whole chassis to want to rotate in the opposite direction from the platter, again described in the statement of the Third Law of Motion. Here we have Albert hearing great improvement from firming up the stator supports and whatever else was done in that direction, even though his Mk3 was already firmly in the grip of his large and heavy hardwood plinth and damped already by his iron block/brass rod device that is in contact with the bearing housing so as to draw off energy. One can only imagine what potential is left untapped when on uses no plinth at all. (I hope none of those guys are reading this thread; I don't want to go there again.) To each his own. Sebastien, Great to hear that you are in a good place. I was in Bill's shop last week and may have seen your Mk2 on his bench. |
Lew, Of course some of us are reading this thread and some.....like me....would prefer you to stick to 'medical science' rather than structural science? Whilst invoking the Laws of Newton may appear to add credence to your statements.......there must be some 'connectivity' to those same invoked laws? Here is a cross-sectional view of the Technics SP10Mk3 HERE which shows that.....like all platters........it is a cantilever supported only at the platter support around the spindle which then takes all the load to the bearing. If someone can demonstrate any other contacts points between the platter and the outer 'trim'......I'd be obliged? Now if the spindle and it's bearing are of the minimal friction type desired by many designers........where precisely are any loads distributed to the 'whole chassis' as you claim? |
Henry, I should have known that, like the shark in "Jaws", you were lurking out there. I never should have gone swimming here. I could not care less about this issue; I have made my decision, and you have made yours. This does not make you or me a bad person. Moreover, I do not think the choice is a make or break one; I am sure your system sounds wonderful. Carry on. Now, will you release my foot so I can swim to shore? Thx. |
Hi Lewm, It's impossible that you saw my mkII at Bill's place. Bill only helped by email my audio technician here in Montreal for the detail regarding a probe to take a mesure. To give anybody an estimated of the job done and the cost, here it is: -PSU upgrade (all capacitors with high end ones, new IEC plug, new led in front); -Have done all in new silver solders; -Checked all the capacitors values in the turntable; -Adjust the speed; -Lubricate it with original oil. It costed me $150. Sébastien |
Pryso, My system pictures are so out of date that I've considered just taking them down. Both those tables are gone and have been replaced with a pair of Thalman redone MKllls. One is in Chris Thornton's large constrained layered plinth, the other is in the Dobbins plinth utilizing only the platter and motor unit. Both plinths are dual armed. I'm still in the process of setting all this up and may get around to posting better pictures at some point when finished. Tonearms are EPA 500 (6 different wands), an exotic German carbon fiber arm, SME 312s Magnesium and soon a 12" Reed 3P. Lewm, I wasn't aware of this mklll mod Bill is doing until now. Please post all you learn on this especially if you have it done. |
Dear Jim, Albert made me aware of it in the course of an unrelated exchange. At the time, his Mk3 was in Bill's shop to get the actual work done. Like you, I at first had no idea what Albert was talking about. In the interim, I visited Bill in order to pick up my CDP (sadly unfixable), and I got a technical explanation of the mod from Bill (see above, although I still have no idea what is done inside the PS module). At this point, Albert has the Mk3 back in his system and has had some time to evaluate the results. He really should be the one to say, but I can provide hearsay evidence that he likes it a lot. Apparently the ideas come from a third party who provided the wherewithal to Bill. I am interested to read that you were able to mount an EPA500 with a Mk3. I will guess that you use it on the Dobbins' Mk3, because as far as I can tell it cannot be mounted with a stock Mk3 chassis; that big square escutcheon would get in the way; maybe not if mounted in the "primary" position, along the R edge of the escutcheon. (I own an EPA500, but I despair of using it with the Mk3; I want my Reed to remain in the primary position.) Hey Halcro, Sorry I appeared so defensive. I was trying to be funny. At least we agree on direct-drive uber alles. |
Lewm, The EPA 500 is now on the Artisan Fidelity plinth done by Chris Thornton. The main advantage of this arm system is it's flexibility. I got it to try multiple vintage/affordable cartridges. Currently I have five combinations set up that can be interchanged in about 30 seconds. It runs counter to common thought on these forums with it's limited adjustability(azimuth) and mutiliple connection points. You'd be surprised how good it sounds though. That being said, the modern premium arms are better of course. I'm anxious to try the 3P, possibly with an Allnic Puritas or Miyajima Shilabe. Now I'll forever have this mklll mod idea planted in my head too. It never stops does it? |
Sebastian, No, I never changed anything about the mkll to use a CU-180. As far as adjusting speed on the mkll, I don't even know if it's possible. I'm not that technically knowledgable but there's no pitch control built in and the speed is quartz regulated. I liked what I was hearing with the Cu-180 but given it's weight, it made sense to me to use a lighter mat which theoretically should allow the platter speed control to function in a situation closer to what it was designed for. Both the mkll and mklll are overbuilt but the mklll much more so. The added mass of the CU-180 doesn't concern me on the mklll and pitch control is present though I've never needed it. I imagine the CU-180/mkll combination may work well without reason for concern. Readily available at about $200 though, the Boston Mat ll would be my top recommendation for the mkll. I'm just a guy who's used all this stuff and by no means an expert so take this for what it's worth. |
The speed can be fine-tuned, if necessary, by fiddling with the PS. I don't know for sure what is done, but Bill Thalmann can do it. However, if the speed is altered by substitution of a heavier- or lighter- than- stock platter mat, that would be one way to KNOW for sure that the mat is too heavy or too light. That symptom tells you that the change in the inertial mass has screwed up the servo mechanism. |
Sebastien, I've offered this information to another post with a similar question. In the manual for my SP-10 Mk2A it states, "The quartz phase-locked control system and the DC motor with large torque can maintain each rated speed of the turntable even with a load torque of up to 5 kg-cm (4.3 lbs. in.). If 500 tonearms of 2 g. tracking force were placed on a record at the same time the turntable would still maintain the rated speed." Visualizing 500 tonearms arrayed around the platter is a bit daunting. But I would guess the real question is what weight can be accommodated by the spindle bearing without undue wear over time, rather than what will affect speed performance? |
Tim, I know you have quoted that paragraph before, but just now I stopped to think about it maybe for the first time. 500 times 2 gm = 1000 gm. That's a bit more than half a pound. So, by this statement you might say that Technics authorized use of a platter mat that is about a half pound heavier than stock. That's still way less than the 4-lb weight of a CU180 or one of those TT Weights products. Of course, you may fairly argue, Technics was also saying the motor could overcome the stylus drag of 500 cartridges at that VTF. I don't know how to translate that into real world numbers. |