Synthetic granite as used for the late 70's Kenwood KD600/650 is a superior material for a plinth rather than any wood product!
Technics SP10 MK3 Restoration
Just got my SP10 MK3 base (motor unit & controller) back from JP at FidelisAnalog.com
JP
is one of the most knowledgeable on the SP10 MK3 and is the one who
designed and manufactures the MN6042 Speed Control chip that keeps these
and other Technics turntable models still operating.
My SP10 MK3 came with the stock Technics SH-10B5 faux obsidian base.
It
has very low hours of use , no signs of wear at all on the bearing and
not a single blemish, other than some specs of dust and a couple spots
on the copper part of the platter that need cleaning.
but I would
like to have a 2 arm, constrained layer plinth built and have the motor
unit mounted 'naked'. I am presently searching somewhat 'affordable'
plinth builders and suggestions would be greatly appreciated.
The work that JP did to both the motor unit and the controller:
1. Pre-refurbishment measurement to baseline the performance of the unit and to see if there are any underlying issues.
2.
Cleaning of all PCBs to remove the factory conformal coating. At~40
years this coating tends to become hygroscopic which can cause stability
issues.
3. Physical inspection of all solder joints under an
inspection microscope. Many of the joints will exhibit annular
deformities which can lead to joint fractures down the road. These must
be cleared of the factory solder and re-soldered. There will also be
poor joints that need the same treatment. You can’t just reflow as the
solder alloys aren’t the same which can also cause joint failure down
the road.
4. Electrolytic cap replacement and rectifier diode replacement.
5.
Disassembly and cleaning of the motor. Bearing inspection and service
work. Proper Anderol 465 oil is used for reassembly. Motor is then
checked for any areas of bearing drag.
6. The brake solenoids typically needs cleaned, and band tension is adjusted.
7.
Stop/start and speed selection switches in the motor chassis are
measured for contact resistance. Too high of resistance is indicative of
a switch failure in the future. In the control unit I typically replace
all the tactile switches, and the start/stop switch if needed.
8. Relocation of the brake regulator transistor to the heatsink to prevent overheating of the board (factory design flaw).
9. MN6042 replacement installation.
10. PSU ripple check at all critical stages (10).
11. Course calibration is performed and post-refurb baseline measurements for FG spectrum, motor drive phases, etc. are taken.
12. After 48-hour run-in final calibrations and verification measurements are performed.
The basic service returns the unit to factory or better specifications (assuming no permanent bearing damage has occurred). This service is quite exhaustive and very different from the typical work I see of just swapping some caps out, checking some voltages, and adjusting phase tracking.
The advanced service adds on top of the basic service:
1. Replace all polyester capacitors.
2. Replace drive circuit metal oxide resistors.
3. Replace all voltage regulator ICs and update circuits.
4. Replacement of certain diodes.
Rick
72 responses Add your response
I am familiar with Panzerholz used as a Single Board in 20mm and 32mm and I can safely say there is not any knowledge known to myself of it having any detrimental impaction on its properties in when solely chosen as the material for a Plinth. As a material used for plinths it is most likely to have reports on its usage that have close to a 12 Years History and I am not as yet with any recollection of seeing an information being offered informing of the material being unstable and not suitable for Plinth usage. I have discussed Panzerholz with a variety of Plinth Builders via Forums, Private Contact and Face to Face, I know some who have rejected it as a material for the Sonic Quality not being to their liking, but never for the deterioration of the material. During a recent search for a Product from the same producer, I learnt that Panzerholz is also used as the Cabinet Material on a High End Speaker Product. |
Pindac If by denified wood you mean panzerholz or lignostone then it is not stable. The stuff bends. You would need to anchor it to some other material or structure to prevent warping over time. I have seen some very expensive plinths that use panzerholz, and over time, you can see they are starting to come apart. |
@dover I subscribe to the loop rigidity principle - platter, bearing & arm mount must be absolutely rigidly locked together in position to measure the groove accurately. Arm pods in my view are only as good as what they sit on, and often will compromise loop rigidity. This is where my mentors in Turntable Design have guided me to. I stick with this Design Intent and see no reason to seek out an alternative method. Plinth Materials that have very stable properties in an environment are key to this. A plinth must have two properties in my view above any other: 1, It should not deform from its flatness across the different seasons and moisture levels being met in the air. 2, It should not expand in any dimension due to different moisture levels being met across the different seasons. If the Design for the Plinth is to have a materials which offers a Specific Intrinsic Damping Factor Measurement and offer the above properties then Densified Wood is looking likely to be the material to offer these properties. As for Stand Alone Tonearm Pods, much of my listening is carried out on other systems and one uses a Pod. I don't detect that any enjoyment of the music is lost, and it might need a very detailed analysis between the differing Tonearm Mounting Methods to produce an assessment of the Pro's / Con's where listening and perceived sound quality is the basis of the investigation. |
Toho plinth - I discovered vintage TOHO cast iron plinths online. I don't have technics Sp10mkII anymore. But Toho plinth for Victor TT-101 is interesting (not so big and not so heavy). What happens when the cleaning lady, sorry - non binary cleaning supervisor, decides to clean under the arm pod and forgets to tell you they moved it. Answer - a year later you wonder why all your favourite records are mistracking. I subscribe to the loop rigidity principle - platter, bearing & arm mount must be absolutely rigidly locked together in position to measure the groove accurately. Arm pods in my view are only as good as what they sit on, and often will compromise loop rigidity |
That Toho plinth for the Victor is interesting but I don't like stand alone arm pods. me too, you will find one Toho arm pod in this system |
That Toho plinth for the Victor is interesting but I don't like stand alone arm pods. I wish I still had my connections with my favorite pattern shop, they sadly changed owners. I'm sure that the past owner would have let me with his help build a cast iron plinth pattern to my liking. After that, drop it off to a local foundry and toss it up on the Bridgeport to finish. Would have been a fun project. BillWojo |
| Post removed |
Cast iron contains a high percentage of carbon, that's why when you machine the dam stuff you get so dirty. He is just trying to make it sound like something super special. Makes me laugh. That part of Pennsylvania has quite a few pattern shops and small foundry's, or at least whats left of them. If he worked with a small mom and pop pattern shop, than the cost of that pattern would not have been that expensive, it's a few days worth of work at most. Getting the grey iron casting poured is usually quoted on a per pound basis if you supply the patterns. Very cheap. The machine work is very straight forward, nothing fancy. What blows my mind is the 10K price tag he puts on those bases. @billwojo business as usual, cast iron is even cheaper in Russia this is why I pay attention to cast iron plinths, but way before OMA made their own I discovered vintage TOHO cast iron plinths online. I don't have technics Sp10mkII anymore. But Toho plinth for Victor TT-101 is interesting (not so big and not so heavy). |
Claims the SP10R is significantly better than the SP10mk3 - LOL - of course the scarcity and age of SP10mk3’s would have nothing to do with their opinion ! I must admit he did not mention MK3, he said SP10. Turbtable drive in his old slate plinth on the right in his video is MK2 (not mk3) and SP10R is definitely better than mk2 @dover ? You have to remember their market is lunatic billionaire New Yorkers who have never heard a decent stereo, but want something unique - in the looks department. Their mobile ring tone is probably bling bling Yes and No. Steve Guttenberg interviewed one of his customer, it’s about new speakers (not turntables), but the guy is definitely not a lunatic and he owned so many different high-end speakers before he stopped on Jonathan’s (OMA) Fleetwood Deville high efficient speakers. Other people explained better who are the people behind Fleetwood Sound Company (OMA) in this topic. Not everyone is so skeptical, especially people who actually heard those. |
I made slate plinths for several of my turntables, or I should say I had them made on a one by one basis, using Pennsylvania slate and a York, PA, Waterjet shop to cut the slabs. The total cost was always less than $500 per. Here we’re talking about cast iron, but the cost to build vs the retail price for audio products is known always to be wildly out of whack. You pay your money, or not. |
@dover has he started providing any meaningful measurements yet? The machine work does look rather nice, but I had to admit that I stopped paying much attention when he made the claim that the MK3 was digital. @billwojo I know one of the suppliers that makes the plinths is in to SP-10's, so I'd be surprised if they didn't know. |
"Just watched this
with better view of OMA Cast Iron plinth, and to my surprise Jonathan
(at 5:10) said that there is a CRYSTALLINE GRAPHITE in this grey iron
formula."I think you need to do a quick read of the metallurgy of cast iron. Cast iron contains a high percentage of carbon, that's why when you machine the dam stuff you get so dirty. He is just trying to make it sound like something super special. Makes me laugh.That part of Pennsylvania has quite a few pattern shops and small foundry's, or at least whats left of them. If he worked with a small mom and pop pattern shop, than the cost of that pattern would not have been that expensive, it's a few days worth of work at most. Getting the grey iron casting poured is usually quoted on a per pound basis if you supply the patterns. Very cheap. The machine work is very straight forward, nothing fancy. What blows my mind is the 10K price tag he puts on those bases. If this was an industrial part it would be several hundred dollars per piece in small lot sizes. I wouldn't be surprised if I know the pattern shop and machine shop that he used. I used to service most of them.They would be shocked if they knew the end price of the finished product. It's such a simple piece to manufacture, very basic. BillWojo |
@pindac Checkout warrenjones SP10 appreciation thread on stereonet. There is some very interesting information on checking motor runout, platter runout, new platters - there are significant opportunities in checking tolerances and blueprinting the SP10 motor, bearing and platter as part of your build - big gains to be had. |
Just watched this with better view of OMA Cast Iron plinth, and to my surprise Jonathan (at 5:10) said that there is a CRYSTALLINE GRAPHITE in this grey iron formula. This is like mounting a bowl of jello on a 20 tonne rock. If you have ever seen the guts of a Technics SP10 you would know that the case is flimsy, and the motor mounts and stator mounts are almost as bad. The best thing you can do to a SP10 is remove and disassemble the motor, bearing and platter and re-engineer all the mechanical mounting points and pop into a rigid plinth as in the Kaneda mods and the original OMA Slate plinth. Seems to me the new OMA plinth is based around removing the time and cost of gutting the TT as in their earlier solution. The OMA plinth is just a fancy picture frame. Come on - you spend all that money to eliminate resonances and then use wood for the armband - of course each wood has a different sound - bit like buying an ice cream - what flavour would you like sir ? The rest of their presentation is like a Barnum and Bailey circus - Cant pronounce Technics correctly Claims the SP10R is significantly better than the SP10mk3 - LOL - of course the scarcity and age of SP10mk3’s would have nothing to do with their opinion ! You have to remember their market is lunatic billionaire New Yorkers who have never heard a decent stereo, but want something unique - in the looks department. Their mobile ring tone is probably bling bling. |
Just watched this with better view of OMA Cast Iron plinth, and to my surprise Jonathan (at 5:10) said that there is a CRYSTALLINE GRAPHITE in this grey iron formula. |
Yes, those old Japanese Toho cast iron plinths are an eye candy, they also made their own tonearm btw. I remember that Toho in the 70's made wooden tonearms rods with different mass. |
Yes, those old Japanese Toho cast iron plinths are an eye candy, they also made their own tonearm btw. So the cast iron has been used since the ’70s for Technics plinth, it was 59.5 lbs (27kg). The price for TM-10 for Technics was 230 000 YEN as stated in the catalog. |
@chakster Here is an old Japanese TOHO cast iron base for Technics Ooooh that's quite interesting! Similar to the Micro plinth that was made in super low numbers, in a way? Kinda hardcore, but I respect the vision! |
The common reference to the stripped back Motor where the Plinth takes on the role of the the Chassis is a Kaneta Design. I believe there are variants of this method in use to date, and the reports from users I have discussed this method with are made giving a very positive appraisal. Myself and a friend are going down this road as an experiment, along with trialling New Platter Designs as well. This is where Polybentonite Resin Plinths come into their own. When a Densified Wood is not an option, the resin material has Performance Measurements that are almost on parity with a Densified Wood and will also be a version of a massy plinth, such as a Natural Stone. |
@lewm Only the motor unit with cable needs to be mounted to the plinth, as none of the controls on the original face plate are needed/used... all control will be from the remote control. I don’t think it to be any more difficult... just will need an additional layer of material to surround the platter as a top plate. Also totally agree with the plinth needing mass, either slate or constrained layer panzerholtz/baltic birch or maybe even Delignit/Panzerholtz and baltic birch? |
solypsa, There are many aftermarket plinth makers who can remove an SP10 Mk2 or Mk3 motor assembly from its square-ish surrounding escutheon and mount only the motor assembly in a plinth specially designed for that purpose. I think OMA can do that. I know that Steve Dobbins was among the first to do that. Probably others can do that too, for a price. The process requires re-locating the on/off switch and the speed selector switch to some other outboard location, so it is not for the amateur. As to balsa wood, I am a firm believer that the very high torque motors of the SP10 MK2 and especially the Mk3 are best off in a high mass plinth. Otherwise, there is the possibility for the tail to wag the dog; the very high torque puts a rotational force not only on the platter but also on the motor assembly. Nature does not care which of the two rotates. You want the torque to be used to push the platter, only. So the plinth should be high in mass to resist motion. Balsa wood need not apply. This is my opinion. Others may disagree. That's OK with me. |
As usual this thread kinda veered off topic. OP wants a plinth. It sounded at first like OP wants to remove the outer chassis and just use the motor? Iirc... There was a guy in Japan that did this using a light weight balsa like wood. Anyone remember his name? It just goes to show how many ways to slice the 'plinth-pie' :). Heavy, light, stone, wood, metal, mix... I wonder how a stack of that carbon fiber balsa-cored paneling would do? Very stiff and light so resonant freq on the higher end I would imagine...could alternate direction of carbon and wood grain. |
This is a good chuckle. @au_lait Do you know who is the author? Because if you ever read this Romy The Cat blog you can see the attitude of this Russian guy a bit better. For example, you can simply read his opinion on Denon 103 and I’m sure so many audiophiles will be offended :) There are more in his blog. What I don’t really understand is why someone criticize other people Sound System in public after a personal visit, he even posted something about Jonathan’s wife and classical music, but not everyone is into classical music in 21st century! He posted a picture of the vintage horns from the actual Oswald Mil house in Pennsylvania, not the OMA hons from his NYC showroom! As I said let’s be honest. Jonathan clearly explained in this video that he filled up his house with vintage tube electronics, horns, turntables and all that stuff for his own delights! He’s a collector of vintage analog gear first and then a founder of his own company. But I believe his real passion is vintage analog gear. He’s also a film maker. He explained his background on OMA site, it’s an interesting story and many images of the manufacturing process of OMA equipment etc. Actually, far more interesting than reading a blog of that audiophile Romy The Cat who can’t even hire a web designer to make his posts readable and his blog navigation more user friendly, but Romy The Cat, who listen to classical music, criticize people who design beautiful things and running the biggest showroom open for public in NYC (everyone can visit). |
Here is an old Japanese TOHO cast iron base for Technics, Victor, Denon turntables. |
@chakster My experience with Jonathan was personal... it was interactions and discussions with him/others as hobbyists... before those discussions, when he and I discussed his plinths, he was quite the different person. I didn't want this to get negative... as I try to stay positive and enjoy this great hobby. |
@rich121 This is a good chuckle. |
@chakster Of course he was nice to you... you were handing over $$$ and he wanted more of your $$$! No, he never tried to push anything, he did not even tried to sell me slightly more expensive cartridge (but he could). He was a honest dealer, this is what I like. And believe me I ask question BEFORE I buy anything, not after! Other well know dealers in USA simply ignored my questions if there are more than one question or more than one email. Conversations and interactions that I was referring to were non-business... they were interactions between ’hobbyists’ Conversation with YOU personally or someone else ? If you don’t have personal experience with OMA you’d better not comment. Some hobbyists here on audiogon are very rude, but it’s a free speech, not their job, everyone can be in a bad mood and everyone has an opinion. I’m sure there is nothing wrong with the reputation of OMA as a company, they got their customers and they got their unique product to offer on the market. Let’s be honest! P.S. I remember companies like B&O, today rich people are buying them because of unique design for their interior. Unique design cost money. OMA is not B&O, so I believe it's a combination of sound and vintage oriented design. But I never heard their speakers in real life, I know people who tried them in NY showroom. |
It’s all a matter of taste after all. Someone may like the old lead console made in Japan in the 70’s, but It’s just another very simple metal frame. Back in the 70’s/80’s this company made lead consoles for Sony, Technic, Denon and others. I think it’s nothing special and custom made plywood plinth could be better. Regarding OMA, again, Most people look at this company as “something beautiful” regardless of price as very few people can afford OMA products. But their plinth priced just like any other premium plinth from well known manufacturers. Reading a negative posts about OMA I must admit that I have personal experience dealing with them about 5 years ago and my experience is very positive! He’s a dealer or Schroder, Ortofon, Miyajima, Schick, SoundSmith ... I bought my Schick “12 inch tonearm and Ortofon SPU cartridge from OMA for my Technics SP10mk2. Jonathan personally replied to all my email and answered all my questions, it was very helpful. In fact his price eas cheaper than German price for Schick tonearm so it was a very good deal. It was excellent service, no rudeness at all (I have no idea what you talking about @rich121 ), I asked so many questions and got all the answers, Jonathan was very helpful, I even tried to buy his demo Miyajima carts few years later and we tried to negotiate about the price, everything was nice and smooth like it should be. Compared to many other well known dealers I tried to communicate by email at that time asking questions, Jonathan was the best! This my experience with OMA, I had to say that, let’s be truthful. I can imagine that some people may not like what he think about Direct Drive turntables (his preference is clearly DD and this preference is not popelar in high-end community). Regarding his own products it’s easy to watch his videos where he claimed they are not a typical high end company. So do not expect them to sell you what you can find in a typical high-end store. Their demo loft is beautiful and some of his speakers, stands, plinths, amps are beautiful and made with a great passion! He’s got a well educated designer or design team that other high-end companies can only dream about. His stuff is art, it’s nice to have an independent company like OMA today. He’s doing a geat job explaining people on his youtube channel a lot of things about history of audio (horns, tube gear, turntables). He’s doing it not for audiophiles, but for younger people. His showroom in NYC is open and anyone can come, you don’t have to buy! This is great. |
@au_lait Thank you for the suggestions. Very good to know. As for Jonathan @ OMA, he lost all respect from me and many others in his first years of business. On many occasions he insulted and otherwise turned away many people/friends in the hobby due to his arrogance and just plain rudeness, some who actually have posted on this thread. He will not get my business. |
Russ at Layers Of Beauty is excellent and priced better than most. I built a 2 arm panzerholz plinth with the drain etc for my SP10 MK3 (also dialed by JP) and when I needed advice Russ was a truly great guy and helped me. The panzer cost me about 1k all in, about $50 for some maple veneer, and the rest is all elbow grease, lots of it. Cusworth plinths can also be made to order, all hand planed, can be as simple or novelty as you like, albeit more popular for older idlers. Check Audio Grail for examples. Personally I would never give any money to OMA. All ego and hype, and that stuff looks steampunk. Maybe it’s not “just a wood box” but cmon, it’s just as ugly; weird corners, weird edge lip, hideous large logo, looks like a piece of shrapnel. If you want not expensive and not wood, snd have some patience searching, you can find an old Lead Console by Osaka Canle Co, here’s one (you can find w/ 2 arms) https://youtu.be/oagZKxwmC8E Or there is this: https://www.instagram.com/p/CG-40OXpE_-/?utm_medium=copy_link |
Quote " I dont like plywood or panzerholz because they are dimensionally unstable in the long term - warping, expansion, contraction" ::::::::::::::::::::::::::::::::::::::::::::: Thats kind of both true and false in my experience. For large objects like a plinth and platforms it false. For smaller objects it is somewhat true like in a tonearm. I have large pieces I have been using that I got from work when the plant was moving. Came from machinery delivered and made in the60’s from Germany as skid and protection plates . After the machines so large they were floated on air in place the plates were removed and sat in a cold basement in winter and hot and humid in summer since 1962. I got them in 2003. No checks cracks or warping and straight as could be. Apparently on smaller items like tonearms n such the fibre structure is compromised. This is copied from morningside.... "With standard products, like Panzerholz, much thicker laminations mean there is less stability when using the product on a very small-scale. When you release the confining tension of various layers, above and below, natural wood fibers will start to relax somewhat. *This is not a problem with large objects, like plinths, or bullet proof doors, * " ........................................ I’ve used it in numerous plinth builds , seen it used for engineered self supporting stairs in high end loft conversions etc. Structurally its a very sound material. Ive not experienced the stability or cracking and warping at all that you’ve seen. The pieces I had and have were 5 ft by 1.5 ft by 35mm thick . So much resin , not sure it really could be called birch wood anymore. Its a real blade and bit killer when cut to low or too high an rpm. Apparently Pica wood is much better for smaller objects as its thinner cross lamination is specifically in a way to maintain its strength over a much smaller dimension. I’ve not used it so I can’t say from experience . Panzerholtz was my choice because I have never felt Aluminum was a good choice other than its ease of machining and once cheap price and after reading the specific tests done I pushed forward with what I had. I’ve seen other and heard other’s choices too. Its a matter of your design and materials at hand and what you like n want personally.. Lots of good results. I’m curious about the ebonized bamboo ply you mentioned as it sounds like another viable option to look into. Choice is a good thing. Although looks are very subjective, few could argue the skill, time, effort and cost of machinery and materials some of these plinth’s take to design and build as well as business costs. Let alone the results. a "300 dollar plinth"... thats basically a board with a hole in it. Cheers https://www.lessloss.com/page.html?id=80 |
As Salvador Dali said - "It is good taste, and good taste alone, that possesses the power to sterilize and is always the first handicap to any creative functioning" If you actually read my post above I make my own plinths using either ebonised bamboo or engineered stone - nothing like the Woodsong/Artisan Fidelity plinths. Would be nice to see a picture of your plinth then @dover I asked: When SP-10mkII was in my system my cartridge was this ZYX Premium 4D SB2 (it’s $5k modern LOMC) and Airy 3 with silver coil (another $3k LOMC). At the same time in MM arsenal these two beauties with EPA-100. Am I missed something? You said: Yes, a decent turntable. I want to remind you that this is a TECHNICS thread, the OP is happy with fully restore MK3, but you think we’re all missed a decent turntable, you know better as always. You forgot to tell what is a decent turntable if the Technics SP10mkII or MKIII are not good enough ? |