And why revive an 8 year old thread to take a poke at 2juki? I don't see where he was even mentioned upstream.
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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. |
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? |
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. |
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. |
Sebastien, You didn't ask me, but I have used SAEC SS300 and Boston Audio Mat2 on my SP10s. Both are a clear upgrade over the factory rubber mat, but I have come to slightly prefer the Boston Audio. I also use a Mat1 on my Lenco. |
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. |
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. |
Addendum: The critical word in my first sentence was omitted by me: "If the CU180 weighs 4 lbs, I personally would HESITATE to use it..." Sorry for the caps. |
Sarcher, I agree. Carry on. There are many others who do the same as you, so obviously the net results cannot be so terrible, in fact must be good. |
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. |
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. |
I think the Mk2 mod can be had also, at this time and for much less cost. |
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. |
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. |
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. |
It will go either on the L07D or the Mk3, in either case as a secondary tonearm (meaning mounted at the rear). In either case, I first have to create the mount. This is certainly one way in which the plinth is a pain in the arse. Right now I am having too much fun listening to what does work. |
You're right, but was that one, or any model in the DD series, ever supplied with the CU180 mat, OEM? They also made the DDX-1000 and DQX-1000, minimalist direct-drive designs that I know for sure were supplied with rubber mats, had relatively lightweight platters. |
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. |
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. |
Sorry, 1000 gm = 2.2 lb. What a yutz I am! |
Dear Sebastien, See above the interchange between me and Tim (Pryso). For sure, the MkII was designed around its stock platter and mat. The OEM rubber mat weighs, as I recall a bit less than one pound. (I weighed mine on a kitchen scale, but I can't recall the exact result.) So of course the whole was not designed for a 4-lb mat. However, it is clear that because of the torque-y motor, there is some "headroom" to use a heavier mat. The question is "how heavy"? That is to be determined by the end-user, I guess. I am a bit more conservative than many others and so would not consider going much above 2 lbs. But I think we can agree at least that 4 lbs. is about at the outer edge of the envelope. Lots of people report good results with the MS mat and with TT Weights mats that also weigh 4 lbs, so I am not about to say that it can't work well. Like Tim said, at some point, in addition to speed stability, one also has to consider the wear on the turntable bearing of using a much heavier than OEM mat. FWIW, I used an SAEC SS300 mat on my Mk2, which by coincidence weighs not much more than the OEM mat and sounds a heck of a lot better. Same goes for the Boston Audio Mat2, which I now use on my Mk3. |
Sebastien, What turntables, besides those made by Micro-Seiki, were designed for the CU180? If what you have in mind are all the Micro-Seiki ones, keep in mind that they are all belt-drive types. In comparing an M-S turntable to an SP10 MkII, both using the same CU180 mat, you are still comparing apples and oranges. The issues with belt-drive are entirely different. Anyway, by all accounts you've made a great choice. |
Sebastien, Glad you are pleased. I am quite sure that the CU180 would be a big upgrade vs the OEM rubber mat. (Almost any not-rubber mat would be, I think.) Albert will speak for himself if he disagrees, but I do think he now uses the Boston Audio Mat2, on his SP10 Mk3. |
Dear Halcro and Dover,
I am trying to reconstruct each argument.
Halcro, you seemed to infer, back a few months ago, that a plinth cannot have much effect on structural rigidity of the Mk3, because of the way its spindle/bearing housing is supported within the chassis proper. Ergo, Newton and his 3rd Law go out the window. Is that a fair re-statement of your thesis?
Dover, It seems you are supporting my side, but you are also arguing with something I may have written earlier about whether you can hear the speed correction going on with a servo mechanism. Did I say that? Have you really heard the very same Mk3 that was originally modified a la what Bill Thalmann has recently done with Albert Porter's Mk3? (Bill did tell me that part of the cost of the modifications is due to some financial arrangement with their inventor.) And are you indeed saying you disliked the sound due to an aberration you attribute to audible action of the servo? I hope I was not so presumptuous as to say you cannot hear what you say you hear. I do hear a slight coloration with a fully serviced SP10 Mk2, but I cannot necessarily attribute it to servo action. However, I hear no coloration at all, or less than with any other tt in my memory, with a similarly prepped Mk3, in my slate and wood plinth. That's just me reporting my own observation, not gospel. Your re-statement of my description of the effects of the latest mod to Mk3 (and Mk2, if so desired) is spot on, by the way. |
Bill can do it for the Mk2 as well. In fact, for some reason the cost is much less vs the Mk3. Ask Bill. |
Dear Dover,
I hope you did not think I was attacking you for not liking the Mk3. Of course, you are entitled to your opinion. Nor would I care to make the effort to change your mind. But I am interested in what you know about the Mk3 mods that were done by Bill to Albert's Mk3. Can you describe them in any detail? For one thing, I am curious about what is done to the power supply module. For another, I wonder whether the inventor is supplying some actual parts to Bill, for him to effect the modifications. Also, where do you live? Seems you are somewhere outside the US at times, other times not.
Just for my own curiosity, can you say what turntable(s) you do like and also describe the remainder of your system? My system is posted here. Thanks for your input. |
Sebastien, Perhaps we shall find out. |
Thanks, Albert. I thought I had been told that there were some mods to the outboard PS associated with your upgrades. I was obviously misinformed, or my memory is playing tricks. Is "Richard" the guy who invented or first devised the beneficial modification(s)? Even Dover admits in the quoted paragraph that he is unable to make a judgement regarding the modified MK3, because so much else about the system is in constant flux. |
I came upon this old thread whilst searching for more specific information about the Krebs SP10 Mk3 modifications. Suffice to say that I can find none on the internet, aside from the generalities revealed in this thread. My interest is piqued because I am now finally considering having my Mk3 re-seated by Steve Dobbins in one of his plinths. It would seem that Steve's approach addresses all of the same issues as those addressed by the Krebs mods and for me also makes it much easier to mount two tonearms of any type for use with the Mk3. (I wrote earlier of the fact that the stock square Technics escutcheon surrounding the platter pretty much interdicts the use of anything but a 12-incher as a secondary tonearm.) I also have resolved to cut back on the number of turntables I own in the process, since I have decided that the Mk3 and the L07D are supreme.
So, Sonofjim was about to be able to experience BOTH the Dobbins Mk3 and the Krebs Mk3 in his home system. Tell me, what do you think by now? Pinging Sonofjim... |
If it comes to that, I like what Steve Dobbins did to Mike Lavigne's Mk3, removing the motor entirely from its chassis and imbedding it in a solid plinth. I would be reluctant to do that with my Mk3 for fear of diminishing its value, and because it was NOS when I got it, kind of an historical object that also plays music. This did not prevent me from going all out with the plinth design and construction, however. I have held off on the Thalmann mods because of cost. Eventually, I will likely cave in and get it done. The Cotter and certainly the Kaneta mods pertain to the Mk2 only, I think. Also, I think Halcro's objection to the SP10 construction is relevant more to the Mk2 than the Mk3. (Maybe that will get a rise out of him.)
So, can you say what turntable(s) you do favor at this point in time? I myself am not ready to say that the Mk3 is clearly a winner vs the tweaked L07D, at least not yet. For sure, I could live happily with either one. |
That's pretty funny, actually.
The main reason I am tempted by the Dobbins approach is that it allows a much wider choice of tonearms. The stock Mk3 chassis gets in the way of most 9-inch tonearms, and on the wide sides (rear and left) one would be hard-pressed to mount and align properly anything but a 12-incher, surely at least a 10-inch is minimum. |
I too asked Dover what turntable he currently favors, but the question remains unanswered. I suspect that Dover does not want to get into an argument about direct-drive vs some other technology that he may favor, and I don't blame him. I can only assure him that I am merely interested to know what he likes, because I respect his judgement. |
Dear Richard and Albert, As you both know, Bill Thalmann would be the one to upgrade my Mk3 with the Krebs mods. (Until 2 days ago, I did not know Mr. Krebs' identity. Nor did I know enough to credit him; now I do.) Bill's shop is about 30 minutes drive from my front door. Perhaps I was misunderstood to have stated that Dobbins does the Krebs mod. I only meant to say that it would appear that both approaches (Dobbins and Krebs) are targeting the same issues as regards the operation of the Mk3 motor and servo system. I fully realize the methods may be very different. I am curious to learn more about the specifics of the Krebs mod, as Richard knows from our recent private correspondence. |
I guess I will ask another question and also bump this thread. Albert, did you have any truly objective way to know that the Krebs mods made a significant improvement in your Mk3's performance? Or are you reporting a subjective impression, which is perfectly OK? |
Dover, I think I know what you mean. The L07D represents a very different approach to direct-drive, compared to the Technics one. IMO, the L07D is vastly under-rated compared to the Mk3, which is not to say that the latter is not superb.
BFalls, I responded to your Audiogon message. Evidently you did not receive it. Audiogon may not want us to talk privately. |
All points well taken, altho thankfully all of the turntables you mention are more attractive than the metaphor you chose to describe them. |
Dear Sonofjim, Thank you for your detailed response. I am treading on "little cat feet", but I have come to understand that a Krebs-modded Mk3 in a Dobbins plinth would not be too much of a good thing. Mr. Krebs was kind enough to send me some photos of his personal Mk3, and it is sitting in a Dobbins-type set-up, i.e., the motor is taken out of its chassis and directly mounted into his plinth. Likewise, I would guess that a Krebs-modded Mk3 in a Porter plinth is pretty fantastic. But I had no intention of starting a controversy about after-market plinths.
IMO, the difference between now and 25 years ago is mainly the zeal with which those of us in the here and now are approaching the art of playing a record. There was not much of a market for such craziness back then, except the tiny niche occupied by Merrill and a few others. Suspended tables with flimsy plinths, a la Linn, were also more in vogue back then. Fashions change with time. Remember the Woody Allen movie "Sleeper", where he wakes up after 200 years to find that steak and ice cream sundaes are health foods? |
Lbelchev, I would guess that the Mk2 and Mk3 are just so completely different that it was just fortuitous fall-out that resulted in the Mk3 having lower rumble. Moreover, somewhere around that time, the method for measuring TT rumble was changed such that the newer numbers were all about 3 db better than before. Hence the Pioneer P3 vs the P3a; the P3a has better/lower rumble specs, but the two tables were measured differently, and I am not sure there is any structural difference at all between them to account for that difference, save for the method used to measure rumble. (Of course, I could be wrong.) |
Tim, I should have added that because of the drastic difference in shapes, a plinth custom-made for a Mk3 would not fit the submergible portion of a Mk2 chassis. It's a square peg into a round hole, where the side of the square is at least the same as the diameter of the hole, and maybe bigger. Vice-versa mismatch would "work", as described. |
Lbelchev, When they wrote "sophisticated cabinet construction", it sounds like they were talking about their plinth, which I believe was supplied as an accessory to the Mk3. But is it possible, or do you think, they were referring to the chassis proper of the Mk3? If the latter, very interesting to me. |
Tim, the Mk3 "chassis", as you know, does not contain any onboard circuitry. It is merely a cradle for the motor and a mount for the on-off switch and the strobe. Ergo, the bit that hangs down below the square escutcheon (the "dog's balls", in Dover's parlance) is circular in aspect when viewed from below, and its diameter tapers toward the bottom. IOW, it encases the motor assembly, only. Thus it does not have a potentially resonant cavity (or at least the cavity is very much smaller and confined), compared to the Mk2 chassis. You cannot put a Mk2 into a Mk3 plinth, as the former would not fit, not only a square peg into a round hole, but also a square with a side slightly larger than the major diameter of the Mk3 plinth circle. |
Dear Tim, I think my original response does address what I think is your question. From the top side, the Mk2 and Mk3 "chassis'" are indistinguishable, as you suggest. What I was describing is that the part you don't see when the two are installed in any plinth is very different from one to the other. The SH10B7 plinth may indeed work with both units, but if you use the Mk3 in an SH10B7, there will either be empty space where the circular shape of the Mk3 motor housing does not conform to the square shape of the Mk2, OR there may have been a factory supplied insert that makes the SH10B7 fit the Mk3 snugly. Since Albert is among us, I need not speak for him, but I believe his plinths made for Mk2 can be adapted to Mk3 by adding some sort of wood inserts, or so it seems from one photo I once saw. Perhaps AP will comment. |
Yes, if you mean performing the Krebs mods on the Mk2, I too would be curious, as I think there is even more to be gained vis the Mk2 than vis the Mk3. Moreover, according to Bill Thalmann, the Mk2 Krebs mods are less expensive than the Mk3 ones. |
Dear Albert, You wrote,
"My friend (Ken) also has a Krebs Technics MK3 so he's clearly the person to answer this question. He has an ultimate system, very high resolution and pro tape machines that serve as baseline for sound."
I am a bit confused. First of all, what is the question that Ken might answer? Second, I understand that you own and have been listening to a Krebs-modded Mk3. So why would you need to get over to Ken's house to hear a Krebs-Mk3? Thanks. |
Thanks, Albert. I have no personal interest in the Mk2 mod, because I no longer own a Mk2. But I now do understand what you wrote. Ken has both the Mk2 and the Mk3, and you will be able to compare them side by side. Sorry to have been a dunce. |
I also think the Mk2 "needs" it more; the Mk3 is wonderful in stock form. I hear some albeit faint coloration with the Mk2 of a kind that could well be ameliorated by the Krebs mods. |
Ken, Can you describe the remainder of your audio system? Albert mentioned above that you own a very high quality set-up, from front to back. Thx. |
