Apocalypse Now?—Technics sp10 problem s

I wouldn't mind running it constantly, but that won't solve the underlying problem the cause of which I don't know. I don't dare mess with the electronics as my ignorance would do more harm than good.

Corrosion death? Say it ain't so.

This is a legendary table. I don't know anything about it, except that there are forums dedicated to this turntable. Google it's model number and see what comes up. You live in a major metropolitan area,and I'm sure that someone on one of those forums will be able to help you find a qualified service tech in the greater L.A. area who can repair and or refurbish your baby.

Banquo363

I have one of these decks. If it were me I would treat it like my car and get it checked out - don't wait for the problem to get worse.

Put out an area location in LA on this thread and you will have members provide you with reliable contacts.

Whether you have a tune up due or a major repair it is worth fixing. An SP10 is very hard to find and/or replace. If for some reason you dont want to repair it you can sell it in no time here in "as is" or repaired condition.

Its worth fixing and worth more at that point if it has been updated.

Did you know the history on it when you bought it - was it used in a broadcast studio or in a private sound room?

Good luck

These are wonderful turntables and should be repaired. I had one before I found a MkIII. It sounds like the brake may need adjusting and the switches could use some tuner cleaner. The power supply could be in need of some new caps also. Be very careful using any kind of grease only use the recommended bearing oil if anything. There are many forums here for modding and repairing these.
SP-10 Forums

I don't know where you are located, but if you are in the US, I highly recommend that you contact Bill Thalmann of Music Technologies in Springfield, VA. Bill is as nice as people get, honest, and very smart about SP10 electronics, since he has by now repaired and refurbished many many Mk2s and Mk3s. I guarantee that Bill can make your Mk2 good as new for a very reasonable cost. As someone above said, the basic building blocks of a Mk2 should last essentially forever if properly maintained. Your symptom(s) are much too complex for anyone here to diagnose, and it is unlikely that the solution is merely to replace the electrolytic capacitors, which should have been done from the get-go, so seek professional help and gain peace of mind.

Thanks for the responses everyone. I mustered up the courage to open up the bearing well (with Lewm's help--thanks) and there doesn't seem to be anything obviously out of place. No gunk to speak of. However, the shaft that the spindle sits atop has wear to it and that may be the problem--but there's no fixing that, I think.

The brake piston had a bunch of gunk on it. Cleaned that off and adjusted the brake (which was dragging against the spindle--I could hear a swooshing sound as the spindle turned).

Put it all back together and...same damned apocalyptic sound as before (minus the swooshing :). The sound is not quite like gears grinding as I suggested earlier but rather an electronic buzzing like morse code. Hopefully it's not the motor itself.

I live about 30 minutes east of downtown LA. But I'm willing to drive, so it doesn't matter really where the shop is. Even as far as San Diego would be fine since my folks live down there and I could just visit them. I hope there's a west coast version of Bill Thalmann, otherwise I'll just send it to him.

Banquo, two suggestions.

One of the best turntable experts in the US is not far away - Brooks Berdan (I think in Monrovia). I would call him Monday morning and ask for his recommendation.

If that fails send me a PM for a suggestion in San Diego.

Good luck.

I agree with Tim. If Bruce Berdan is still working, then he is the guy closest to you who can help you the most. However, last I heard he was ill and/or retired or retiring. Anyway, it would pay to contact him.

When you say that the shaft is loose, can you amplify on that? Do you mean that the spindle can be "wiggled" when seated in the bearing well? If that's true, it is unlikely that this extensive level of wear occurred during your period of ownership. Is there any visible wobble when the platter spins?

Thanks Pryso, I'll call Brooks Berdan tomorrow. I've also emailed Bill Thalmann.

Lewm: nothing is loose and there's no wobble that I can detect. When the spindle housing is lifted off the motor, there is a shaft that is revealed. The top of that shaft (which comes into contact with the bottom of the spindle housing) is worn. It's not smooth and there's uneven wear. I don't know whether that it is to blame for any of the symptoms. This was a studio TT so it doesn't surprise me that there's some wear. What does surprise me is that the brake looks brand new (maybe they rarely used it?).

What puzzles me is why the buzzing noise and speed issues go away after running the motor for a bit. I'm happy that it does, of course, since it would be useless to me otherwise.

And I've noticed another symptom just now: when the buzzing reaches its peak level, the entire TT vibrates (I have no plinth; the motor rests on 3 Audio Technica feet).

You may want to check here:
http://www.artisanfidelity.com/Detailed-restoration-photographs.html

Dear Banquo, Your verbal description does not paint a picture I can remember from having been "inside" my own SP10 Mk2. Perhaps I will take a look to refresh my memory. In any case, it is a relief to know that you don't have any spindle or platter wobble.

Now you say you have no plinth, it is possible that the vibration you experience at start-up is normal, if it goes away within a few seconds. The high torque of the motor WILL cause the chassis to want to spin in the opposite direction from platter rotation. (Remember Newton's 3rd Law of Motion?) At turn-on, max torque is elicited until the platter moves off from rest. During that brief period, it is quite normal for the un-anchored chassis to vibrate irregularly. I don't know whether this is the complete explanation for your dilemma, but it certainly sounds like this normal phenomenon is playing a role. In my own case, my Mk2 acted like it could walk off the shelf, when I started it up prior to its installation into a plinth. I daresay the Mk3 might actually take off in that scenario. Try physically restraining the chassis, and tell us what happens then.

Dear Lewm: if you look at the site rwwear linked to, and open up the second pic down on the left, you'll see what I was trying to describe. The spindle goes into the hole and the piece of metal above the hole is what is worn on my TT.

The vibration I notice today is definitely not a result of being plinthless. It doesn't go away seconds after start up, but rather remains as long as the dreaded buzzing noise remains. That is, for minutes after starting the motor for the first time. If I play records for hours after that the buzzing more or less goes away and so does the errant vibration. You are right though that being plinthless causes a very brief little shake right at each start up, but that's not what I'm referring to.

You've seen, I'm sure, the thread on the 'nude' Victor TT. I'm trying to see whether I like the Technics nude. So far no complaints. The Audio Technica feet are excellent, and serves to restrain and isolate the TT. Even with the errant vibration, the TT hasn't actually moved its location. And during play, I can drum on the platform the TT rests on without sonic penalty. I might try fabricating a plinth later but I see no reason to right now. The set up is ugly as sin, especially my makeshift armboard (which sits atop 4 Herbie's tenderfoots), but sounds delightful. Now if I had a MkIII, as you say, the motor on that is much more powerful and probably requires a plinth.

A couple of months ago my friend’s SP10 MKII had the same slight grinding noise at the bearing. At first, he thought it was the problem of either the main bearing or some of the chips under the turntable chassis. However, when we switched the separate power supply to the one I had, the problem went away. It turned out that some of the electrolytic caps in his power supply had gone bad. After he changed all the caps in the power supply, all is well, and even the strobe light, which hasn’t work for a long time already, is now working.

On the other hand, I have a SP10 MKII which has erratic speed due to a bad speed control chip. I was told this is not fixable since even Technics doesn’t have that chip in stock anymore.

There is so much "urban legend" surrounding these turntables, that it is difficult to find the truth.

Thekong, In fact, I doubt Technics has ANY parts for ANY of these turntables, but the chip you need may be the same as that used in later Technics tts, such as the recently discontinued SL1200 series and the related turntables (SL1500, SL1600, etc), some of which are available quite cheaply on eBay. Also, I found a supposed NLA chip for my Denon DP80 by doing an internet search which led me to a company in Hong Kong that is an information depot for many other small electronic supply companies in the Far East. Through their auspices I found enough of the Denon chips to go back into DP80 production, if necessary, for as little as 35 cents each. See if the faulty chip has an alphanumerical code on it, and put that right into Google. You may be surprised, pleasantly.

Banquo, I will take a look at the site. Now that you describe your problem in more detail, I still say that you should not be taking advice at a distance from us amateurs. Your problems might all be solved by changing out your electrolytic caps, which, as I said above, should be done anyway if not already done. But regardless, you need Bruce Berdan or Bill Thalmann or someone of that ilk. A good machinist can probably repair the worn part that you are looking at, assuming even that it needs to be done. One bit of advice I do have: don't be running the motor without the platter. Without the platter, the servo mechanism will be very unhappy. By the way, if you are using a very heavy platter mat OR a very light one, in relation to the weight of the stock rubber mat, try going back to stock and see what happens.

Re plinth-lessness: You guys are really doing two non-standard things; you are running without a plinth, and you have your tonearms mounted on a separate pod. I have an open mind about the plinth issue, but IMO it really is better to fix the tonearm mount on the same mechanical linkage with the turntable bearing. However, I know very well that some disagree.

Dear Banquo / Lewn

I can confirm its not the plinthless setup - that thread was my inspiration as well to pull mine out of the plinth over the holidays. I dont see myself going back to a plinth anytime soon. Too much flexibility now with arms and sound improved too.

With the mkII there is no issue but with the torque of the mkIII - well I don't have one so cant say.

What I have noticed is that folks give the mk II table a try plinthless while waiting for their plinth. They dont secure it properly and the arm pod is who knows what. Even BDR cones with blue tac will hold the mk ii down no problem. I use an ET arm with mine and if it is moving on me I will notice.

I can put up a link to some pics later?

Ct0517, So let me get this straight: You are running your Mk2 with no plinth, AND you have an ET2 tonearm mounted on a separate something that is completely disassociated from the Mk2. Is that correct? How do you assure that the ET2 is on the exact same plane with the Mk2 platter, so that the cartridge is not riding up or downhill as it traverses the LP, not to mention all the other crucial spatial orientations associated with use of a straight line tonearm? Anyway, if that is your set-up, and if it works, go for it.

To me, this might prove that we are all much too anal; the playback process apparently may tolerate all sorts of alignment and resonant inaccuracy before we start to hear the problems. One thing I definitely will agree with is that a "bad" plinth is quite likely to be inferior to proper implementation of the no-plinth idea. I would like to hear from someone who went from Albert Porter's Panzerholz plinth or a Dobbins plinth or the like, to no-plinth and preferred the no-plinth.

As I said, my TT was used for broadcast. Those guys drilled a tonearm hole right through the Technics metal top. When I first got the TT, I mounted their tonearm into that hole. The spindle to pivot distance was perfect but I could not get the correct height so that VTA was always way too high. Either they didn't care or else had a very low hanging cart. So, having no plinth, I had to fabricate a separate board to hold the tonearm. Obviously, there's no point in comparing the two set ups, since the former was so compromised.

And, to be clear, I'm not saying plinthless is better. It just sounds so good that I don't feel the need currently to spend money on fabricating a plinth. This is fortuitous since I'll have a hefty repair bill coming my way, I'm sure.

Would it sound better with a plinth? I hope so, since that way I can get better sound without buying a different TT. But, as Ct0517 said, tonearm flexibility is a strong consideration in favor of going without. I'm new to vinyl and want to be able to play around with different arms in the future.

Banquo, Don't sweat it. You did good. Actually, the only thing I don't like about the Mk2 and the Mk3 is that square escutcheon that surrounds the platter. The square shape t makes it quite difficult to mate the turntable with more than one tonearm and/or to use a standard 9-inch arm that is offset for a VTA tower, like the Triplanar, Talea, and Reed tonearms. 10.5- to 12-inch arms work much better. That's probably why those guys drilled the hole. Sounds like your tonearm is secured to the chassis, not free-standing.

Dear Lewn
I will post a link to some pics later that will answer your questions.
It is all very simple actually. The flexibility to setup arms when not restricted by a plinth is huge. You can move the table in place and not touch the arm if you wanted to. I discussed and exchanged the ideas and pics of the ET setup with Bruce as well. Hearing is believing as they say.
Standard is a very strong word – to me it implies constraints and rules to follow- this is a hobby about passion and enjoyment – constraints and rules don’t fit in - lets use guidelines.
Manufacturers have to follow standards and guidelines for their products. its up to us as users to push those guidelines (common way of doing it) then the demand follows if it’s an idea that works and manufacturers have to change. Look I could be in a plinth again - who knows – all I know is I am enjoying my music and not worrying about whether I "did" the right thing.
Regardless –I have learned that the table itself is 3rd in line of importance. Once you have solid reliable platter speed have dealt with motor vibrations and the sp10 has NO RUMBLE by design you are good to go.
This setup I think further isolates more so the arm and cartridge which are 1 and 2 in importance to me from any motor vibrations. I see more and more high end manufacturers using arm pods now and I think you will see more to come. I think my sound improvement was because the arm is no longer on the same base where the motor is turning where it picks up more vibrations regardless. So the sp10 in the plinth or not is not the issue here. You can still put the sp10 itself in a plinth if u want – but aren’t u adding another layer or stage then.
Look I also have a VPI TNT with another ET arm and I did ab testing with both the sp10 in the plinth and the TNT. They both make beautiful music.

Sounds like your tonearm is secured to the chassis, not free-standing.

No, it is independent of the chassis. I drilled a hole in some plyboard I had laying around and mounted the tonearm on it. I then screwed that piece onto more boards to give the whole thing some weight. The boards sit on 4 Herbie's tenderfoots. This is obviously a temporary solution since the boards are not heavy enough to resist inadvertent bumps--which then messes with geometry.

Halcro's solution of machining 25lb tonearm rests would be ideal but too rich for my blood.

Ct0517, I guess I come across as being more dogmatic about this than I actually am. Really, I am all in favor of doing whatever you like with your equipment. I enjoy the debate, and I can think of arguments on either side of almost any issue where the well-being of my fellow man is not at issue. It's really too bad that we each cannot hear the others' turntables in a controlled setting, to find out more about how these many different ideas work in practice.

In the context of your post above, you are reiterating what I wrote previously: There are two entirely separate issues: (i) plinth vs no-plinth (for direct-drive), and (ii) arm coupled to bearing or independent of bearing. On the plinth issue, you guys have stimulated me to give it a try (maybe) with my Denon DP80, which is very near identical in size and shape to the Victor that Halcro uses. Of one thing I am sure: how one seats the chassis on the shelf will still make a big difference, so one guy's no-plinth could sound a lot different from another guy's no-plinth. (I hope we agree that the chassis needs to sit on or in something that at least inhibits it from walking off the shelf. Newton's 3rd Law is not abrogated after start-up.) On issue #2, I think I will go my way for now. However, I was thinking that the most expensive Kuzma set-up features their straight line tonearm mounted separately from their top turntable, much as you have done, albeit both are on brass pedestals that look to be VERY heavy. I don't know anyone else who sells a system like that. All the other tts with pod-mounted tonearms are using pivoted types.

I found a guy near me who says he can fix my TT (not Brooks Berdan). When I described the problem to him over the phone he seemed to know exactly what was wrong. We'll see whether his confidence is warranted. Evidently, he can machine TT parts as well, so perhaps I can get him to make me a suitable tonearm pod. Meet all my TT needs at once!

Lewm: I see the distinction you're making and have read the arguments pro/con for plinths, but am not familiar with the arguments pro/con for coupling tonearms to bearing. It would be great if you could rehearse some of those for me.

The left most foot of my TT sits on the left edge of the platform it rests on. If the TT moved position even slightly the whole thing would have either fallen over by now or else be off the edge. Neither has happened. TT walking is not really a serious problem I think--at least with the Mk II.

Banquo363 - great that you found a contact to work on your TT.

With the ET arm if anything moved the distortion would be audible on the last track. So far so good.


Lewn - the great thing about this project was it was cheap to find out if it worked in my setup. 3 legs for the TT and spikes for the armboard - you probably have spares lying around and about $75 - $100 in material for the armboard. Doesnt have to be pretty, just functional for now. I listen with lights dimmed anyway :)

here is a link to a site that I added some pictures of my project to:

If you want some closeups send me a note and I will email to you.

http://www.canuckaudiomart.com/view_userimages.php?user_id=5181

I got the metal from Metal Supermarkets. The smaller steel armboard was close to 20 pounds. I was obsessed with making it heavy but Halcro rightly pointed out in the nude TT thread about the magnetics problem with steel so I made an aluminum one - twice as big and about 17 lbs. I put a picture of one of the store racks on the site for you so you can see what is available - they cut any size pieces on the spot for you.

I will be making a pod for the VPI JMW 12 pivot arm soon.

Appreciate comments and any tips on making my set up better.

This project was a lot of fun and it got me through the holidays with two teenagers :).

Chris

Dear Banquo and Ct0517,
Great to see you guys trying out the 'Nude Turntable' principle on the Technics SP 10 MkII. It seems your experiences support Raul's proposition that the 'Nude' SP10 may be better than or at least equal to, a plinthed one?
Photos of your set- ups would be informative for all of us and may inspire others to try this meted?
Cheers

My experience supports the proposition that a nude TT can sound excellent. I can't make comparative judgments because I've never had a plinth.

Chris: your set up is so cool. What's that black piece over the Start/stop button?

Henry: your thread and monumental efforts motivated me; otherwise I probably wouldn't have bothered listening to the Technics nude and went to fabricate a plinth straightaway. I also followed your lead on the Signet cart/AT 155lc stylus combo. I haven't had a chance to use it much but you're right about the impressive soundstage.

The black piece over the start button is a safety feature radio stations used to keep from accidentally turning the unit on or off.

Halcro, IMO, no one has proven anything until someone who has an excellent plinth can tell us that his dd tt sounds better without it. Even then, the result is subjective. Banquo has it right in that respect.

Banquo, I join in those who are glad you have found competent local help. Can you divulge the name of this person? Others in your area might benefit.

I have a local friend who owns a very successful machine shop. They actually make scientific instruments, but at his home he has every machine tool you can imagine, including a computer-operated mill. He has helped me already making odds and ends for my tts, and I am sure I can enlist him in making something to serve as a no-plinth. (He is basically retired, has hired someone else to run his business, just sits home and collects money.) I am thinking along the lines of the Grand Prix Monaco or the Micro-Seiki 1000DQX, basically a frame that holds the chassis firmly in place with three outward going "legs" upon which one can mount arm boards that are therefore coupled to the structure. Brass and alu in combination might be good structural elements. You can buy nice blank slabs and/or rods, etc, of either on-line for reasonable prices.

On coupling tonearm to bearing, perhaps I misspoke. It would be better to say that I think the tonearm should be coupled to the chassis. Do I need documentation for that idea? About 99% of all tts ever made provide that sort of coupling, some better and more emphatically than others. Oddly, all of Kuzma's lesser models do it that way; only the Airline system does the separate pod. Plus there are a few other high-price entries that also use pods to mount tonearms. I don't like the idea. Regardless of gross movements that could screw up alignment, if there is any chance that the arm pod will be subjected to vibration or resonance that is not also simultaneously experienced by the platter and bearing, then there will be motion of the structural center of the tonearm (the pivot) with respect to the LP. How can that be a good thing for a cartridge that is trying at the same time to trace a groove in an LP? I think the tonearm pivot (in the case of a pivoted arm, of course) and the platter/LP should move as one entity only. That's my story, and I'm stickin' to it. But this is theory we are arguing, not the idea that any one person's system that employs a separate arm pod could or could not be pleasing to the ear.

Tsk tsk Lewm.
I believe it was Raul who started this whole Project (at least for me), by stating that his Technics SP10 Mk2 or Mk3 sounded better 'nude' than in a plinth?
So he has heard it both ways.......and you haven't? :-)
But perhaps you will say that Raul's plinth was not "excellent"?........and this I fear will be the standard response of all who insist on plinths.
If it doesn't sound better in a plinth then the plinth is not "excellent".
A circuitous argument unwinable by the opposing camp? :-(

Hi Halcro, I am not arguing and never have argued that I know that a good direct-drive table sounds better in a good well-designed plinth than in a no-plinth. I have argued only that I like what I hear from my own tt's in a slate plinth of my own making. In other words, my experience is about as broad as yours on the other side of the coin, which is to say, not very broad.

Raul does not like it when I write this, but in my opinion (please note), marble and granite are not the best materials for a plinth, or at least their use is controversial. (Raul's plinth was made of marble.) So, while I respect Raul's observation that he likes his present set-up better than when he had a plinth, it does not tell me much about the relative merits when the plinth is a known high quality type. (As I wrote elsewhere, my SP10 came in an MDF plinth that sounded dreadful.) That's why I say I would like to hear from someone who has gone from an Albert Porter or a Dobbins plinth to a no-plinth. So, yes, I am saying that Raul's plinth was not "excellent" or at least I don't know that it was excellent. But I don't "insist" on anything. In fact, your experience has stimulated me to give it a try. I want the best sound reproduction possible (defined by my ears and brain), and I don't give a hang how I get there.

On the other side, it is tough also for you no-plinthers to argue on principle that your way is best. Why did the top engineers of Technics, Kenwood, Pioneer, etc, all develop elaborate plinths for their moon-shot efforts at a state of the art direct-drive turntable back in their heyday? (This is meant as a rhetorical question; no response is required. I'm just sayin'.) Kenwood even invented a new composite material to use as the basis for their multi-component plinth structure, which weighs 65 lbs in the L07D. �And they started with a coreless, slotless motor that has inherently less cogging than that of the SP10s.

Banquo – thx for the feedback on my setup. Most family members think I am losing it so it is good to hear encouragement - thank you and yes the black button is a cover to keep it from being pressed accidentally when it was used in a broadcast studio. .
Lewn – I have a couple of turntables the other being a VPI TNT - it has a plinth and I enjoy it.
Great that you are giving the plinthless a try and if you use a pivot arm can’t wait to see how you set it up so I can get a second set of ideas for mine.

For the record I mentioned in an earlier post - I did AB testing with my TNT and SP10 in a plinth. I used two two ET arms and a Dynavector xv1.
This AB testing confirmed to me that my SP10 plinth performs as it should - using the benchmark that the TNT plinth is a good one. Could it be made better - maybe - and I was thinking since it was DIY about another plinth but then I saw Halcro’s thread and that got me going, like you, and I tried it. It sounds better to me so I am sticking with it for now – who knows where I will be a year or two from now.

Finally - Standards, Guidelines, now the word principles – its all the same – think out of the box - go with what your ears tell you.

From my thinking even if the plinthless setup is as good as your current set up - it wins due to the all the advantages going plinthless brings when it comes to your choice of experimenting with different arms.

If you don’t like it - its cost you about a tank of gas to find out – at Canadian prices : )

Cheers Chris

FWIW, My slate plinths are huge, and I could mount as many as 3 tonearms with much much less effort than it would take to de-plinthify my SP10, if I wished to do so. The DP80 is a better candidate for deplinthification. (George W Bush, where are you? Never mind. I don't want to know.) But I think I am guilty of going way off topic. On the other hand, Banquo seems happy and that's what counts.

Ct, Plinth for belt-drive is a whole other kettle of fish. I had come to prefer no plinth for belt-drive, when last I owned one.

I visited the guy who will try to fix my TT. His name is Mirko Djorkevik and he has a shop in Huntington Beach, CA. He listened to the noise emanating from my TT motor and says it's the shaft that the spindle sits on. It's the same thing I said, earlier in this thread, was worn when I opened it up a couple of days ago. Since he arrived at that judgment independently of my mentioning anything, I feel we may have hit upon the actual cause. We'll see in a couple of days after he opens the thing up and closely examines it.

Mirko is a great guy and I think he primarily restores Thorens and Garrard TTs. He has an eBay store (user name: sq38s) that sells newly machined parts for those. You can contact him through ebay or if anyone wants his phone #, PM me and I'll be happy to give it to you. It is good for me that he has those skills, since when I opened the Technics up and saw the wear on the top of the shaft, I judged that there's no way to fix it but to replace it with a new one. Hopefully, it's possible. I'm also having him machine me a tonearm pod and some new counterweights for my tonearm. No problem, he says.

At any rate, I'll update this thread when I see how things turn out. Fingers crossed.

I think Mirko made or used to make a titanium idler wheel for the Lenco L75, and he probably makes space age parts for Garrard and Thorens as well. You are in good hands for a machinist, but I would STILL recommend an electrical overhaul, when time and money permit. I hope it all works out well for you.

Thanks, Lewm. I emailed Bill about costs for replacing all caps in power supply. I'll do that even if Mirko fixes my current problem. Are there electronic parts in the TT itself that need to be overhauled as well? I dread having to pack and ship the entire TT. I should really call Brooks Berdan.

I had Mirko make me the motor clamp just in case I ever have to ship it. But still...

Yeah, he showed me some idler wheels he had lying around. Titanium he said, if I recall correctly. From the looks of his eBay store, it seems like he can machine just about any part for those idler drives. Tempts me into getting one.

Too bad there remains so many questions about plinths for Technics and other quality DD tables.

On one hand we have Albert Porter who found sonic delight with ever more massive plinths for his series of SP-10 tables. And the fellow who restored and built new plinths for mikel favors high mass designs. Jweiss has experimented with SP-10 plinths for a few years and his current preference (in slate) weighs about 200 pounds I believe. And if you look at the plinths designed by Technics engineers for their own tables, they increased the mass of each succeeding model for the first three, with the fourth only slightly less than the third.

On the other hand we have Raul, the leader of the pack for plinth less set ups. Apparently Raul began with a massive stone (marble? If so, I agree with Lew that was a poor choice because of the higher resonant frequency -- it rings folks!) plinth, then changed to a single sheet of wood just large enough to support his tone arm, while the motor unit was supported by AT feet. Most recently he eliminated the wood mount and now has his arm freestanding of the SP-10 motor unit. A few others also report pleasing results with plinth less set ups.

Now among those who favor massive plinths, there seems to be one point of agreement. Using only MDF gives poor results. That material may work for idler designs but not for DD, at least the SP-10 series. And I think that points up the importance of the resonance characteristics of the material(s) chosen. Some have tried Corian plinths and I've read criticisms of that material as well. The MDF is slightly dull sounding and damps dynamics while Corian is usually bright with an upper frequency emphasis.

My own experience is very limited. When I got an SP-10 I mounted it on a single sheet of particle board (no one recommends that), simply to provide a platform to mount a tone arm. I will say it sounds very good. But building a better plinth has been long delayed due to finding someone with the tools to help in construction and multiple design changes for what I want.

At this point I find myself in full agreement with Lew. First, I wish someone could report on a comparison of an appropriate massive plinth directly against a plinth less set up. And second, given the critical importance of proper alignment of the stylus tip relative to the record groove, I cannot understand why someone would mount their arm independently from their table, thus giving up the mechanical integrity that a coupled mounting provides.

And second, given the critical importance of proper alignment of the stylus tip relative to the record groove, I cannot understand why someone would mount their arm independently from their table, thus giving up the mechanical integrity that a coupled mounting provides.

On a plinthless sp10 what's the other option? My sp10 has a tonearm hole drilled right through the right hand corner of the steel frame, but that just doesn't work because then the tonearm is too high up. Plus when mounted independently, if the tonearm pod is heavy enough there shouldn't be a problem with alignment. See pics of Ct0517's set up: I conjecture that his tonearm is not moving anywhere.

I've read Lewm's argument (see above) defending coupling. I have no understanding of physics or turntable design, so can't really assess it. Can someone who can say some words about it to help out novices like myself?

Perhaps we should start another thread, since those who might be interested this question probably won't look on this one?

Dear Banquo, Bill will replace your caps as requested, but he will also assess the servo mechanism and hunt down and replace any transistors or other parts that are not performing up to snuff. He will also adjust the critical DC voltages and calibrate the speeds. I will predict that the cost can range from about $400 to $800, the latter near to what I paid for him to do my Mk3, (MK3 may require much more work and calibration than Mk2, so I expect closer to $400 for Mk2.)

Re the physics of the tonearm/cartridge. It's not so complicated. Ideally, you want the only motion in the system to be the motion of the stylus in the groove. Any other relative movement downstream from the stylus can either obscure detail or create spurious signals that the preamp will reproduce and amplify faithfully. Thus producing distortion. This is how I see it, anyway.

Bill's quote was on the higher end of your prediction range, Lewm. He'll need the entire turntable. I'm not saying it's not a fair price--I'm confident it is--but, yikes, this is as much as I paid for the TT, including tonearm. Gotta go sell something now.

Ideally, you want the only motion in the system to be the motion of the stylus in the groove. Any other relative movement downstream from the stylus can either obscure detail or create spurious signals that the preamp will reproduce and amplify faithfully.

I think I understand that, but I don't understand why a coupled unit gets one there but not an uncoupled one. If one can suitably isolate an independent tonearm pod, then what's the problem? And even stronger, wouldn't such a set up be better in that respect since it would more completely isolate the tonearm from any potential errant vibrations caused by the motor. I think Ct0517 made this point above.

Banquo, This is way out on the end of arguing the number of angels that can dance on the head of a pin, but suppose in your thought experiment that either the turntable or the tonearm pod is subjected to a vibration or resonance that is not simultaneously experienced by the other. There is NO such thing as perfect isolation. For example, the pod has to sit on some surface, probably the same surface that is also supporting the tt but in a geographically different place. The shelf itself is going to be subject to resonances that create standing waves with peaks and stationery nodes. Suppose the pod is sitting on a node and the chassis is sitting on a peak? Voila', the chassis moves, albeit at a micro level, while the arm pod does not. If the pod is coupled to the chassis, ideally not in contact with the surface of the shelf, then they both move identically in response to a standing wave of mechanical energy passing thru the shelf.

If you got an SP10 Mk2 and tonearm for less than $800, then you got a steal. I suppose the drill hole in the chassis played a role in that low price. But there is plenty of room there for you to spend some bucks on the electronics and still be within market value, not to mention you will know you are listening to the SP10 the way it ought to be heard.

Banquo, you must accept that every material is subject to vibration, it is just a question of the resonant frequency for each one. I'm not a physicist so admit I am not the best person to answer your question. But my understanding is the higher the density of a material (in general) the lower the resonance. This is why some favor high density in plinths -- to lower the resonance point below the critical 8-12 Hz range. (Which could explain why some prefer plinth less designs, if the lack of low frequency damping and a "brighter" sound better suits their systems.)

I believe this translates to tone arm mounting as well. With a secure mechanical coupling between arm and spindle/platter, material frequency differences (example aluminum and brass or acrylic) may be damped. If each stands alone, they do not damp one another, they can move independently. A further point; many do not realize the potential for urban living environmental activity. I live by a busy street. My turntable is mounted on a wall shelf for isolation. But I can put a stethoscope on the braced plywood shelf and hear traffic going by. If you have an amplifier on the same shelf as your turntable you could experience the same thing. In that environment I would not want my tonearm to be subject to micro-vibrations picked up and translated by a base that was not mechanically damped (attached) to the spindle/platter. Again, consider the extremely small movements of the stylus tip to generate signal.

I think your question on isolating the arm from table motor vibrations has two answers. A decent design will minimize motor vibrations to begin with. But if the motor is noisy, there could be an energy path from the motor, down through the shelf, then up through the freestanding arm. By the time the energy reaches the arm and then stylus, the various materials it traveled through will change its frequency, thus it will vibrate differently than the platter and record. When the arm/cartridge and spindle/platter are mechanically coupled, I believe they should at least vibrate in unison, thus minimizing the impact on the stylus in the groove.

I hope this makes some sense and perhaps another person with more technical knowledge can correct or fill in these points.

Banquo - I agree with Lewn that it is worth fixing up the sp10. I believe it will only go up in value.

Regarding this thread - you could link it to Halcro's. I will post further impressions of my set up there.

Here is the email from the designer of the ET arm I am using - Bruce Thigpen.

Chris,

The installation method looks good. It is very important that the tonearm cannot move with respect to the platter, in other words they should be coupled together. It looks like your installation meets that requirement, thanks for the photographs.

brucet

...not to mention you will know you are listening to the SP10 the way it ought to be heard.

There is a lot to be said for that. Now all I have to do is get my wife to share this perspective. She was already rolling her eyes at my bringing it to Mirko when the TT, in her words, sounded perfectly fine. Of course, she is right that it did sound perfectly fine--except when it didn't.

This is way out on the end of arguing the number of angels that can dance on the head of a pin...

I'm a philosopher by training, Lewm, so I rather like this type of argumentation :).

But I can put a stethoscope on the braced plywood shelf and hear traffic going by.

Really? Wow. Glad I don't live in NYC anymore. That's the first time I've ever said that.

Thanks, gentlemen, for offering a better picture of what's at stake.

Ct0517: but your set up is NOT coupled in the sense that Lewm and Pryso are talking about, right? If it is, then I'm really confused.

I'm in total disagreement with the thought that the tonearm should be attached in any way to the 'turntable' or plinth.
In fact, I disagree that the the 'turntable' itself is the most important part of the record playing hierachy :-)
Blasphemy?
Please read my proposition HERE

Hi Banquo - you mentioned you are a philosopher by training.

There is a saying "if you havent actually played the game -how can you have an opinion on it".

I have posted my impressions of what I think is happening in my setup in "laymans" language on Halcro's thread. As they are the inspiration for me doing my set up I wanted to get their feedback on it and see if they agree with my thoughts.

Trust your ears.

Cheers Chris

You don't need to live in NYC. The earth seems to shake easily here in California. ;^)

Dear Halcro, Before we know it you will have your tonearm in New Zealand and your tt in Perth. Carry on.

Before we know it you will have your tonearm in New Zealand and your tt in Perth.

Less tracking error that way :-)

I think that would be classified by any sensible person as a straight line tonearm. But think of the effective mass.