SP10 Mk II vs Mk III


A couple of guys here were planning to do listening comparisons of the Technics SP10 Mk II vs the Mk III, in their own homes and systems. Has anyone actually completed such a comparison? I am wondering whether the "upgrade" to the Mk III is actually worth it in terms of audible differences between the two tables. Possibly mounting either table in a well done wooden or slate plinth mitigates any sonic differences that would otherwise be heard. I am thinking of Albert Porter and Mike Lavigne in particular, who were going to do the comparison. Thanks for any response.
lewm
Microstrip, Interesting reading.

I don't know how serious I am about building a tube supply for Technics. I'm just a fan of what tubes do, especially in power supplies.

Considering cost of the MK2 it's probably not a wise choice. If the supply cost anything near my custom tube crossover ($3500.00), for a bit more money you could do the MK3.
Albert,
You raised the issue of the tube power supply - I think it would be not be a wise move, as low voltage - high current power supplies and tubes do not combine.
Using a battery super power supply could be very interesting, but however one should be aware of an interesting feature of this power supply: if by any reason the +5V power supply fails, the +32.5V shuts down immediately, protecting the motor coils.
Hiho, Have you ever actually seen the Kaneta modifications applied to an SP10, other than the one in those photos? That URL is frequently cited, but there is no hint anywhere else on the internet that I can find to indicate that help (i.e., kits or assembled PS units) in obtaining the Kaneta outboard supply or the custom plinth are really available. I would be interested to read your response or that of anyone else who has been up close to a Kaneta-modded SP10. The schematic is posted, but it looks quite formidable as a DIY project. (I am quite at home reading schematics and building tube gear but have limited experience with ss devices, particularly ICs.)

The Kaneta plinth addresses this issue but taking the motor out of the chassis and place it in the same wood block where the tonearm is mounted.

http://de.geocities.com/bc1a69/kaneta_eng.html
Lew, you got it right. Here is the issue- somehow, you need the arm to transduce what is on the LP. In order to do that, there must be no play between the surface of the platter and the cantilever of the cartridge.

To that effect, the arm must have absolutely no slop in its bearings, no resonance in the arm tube. **Any** motion that is not caused by the LP will be interpreted as a sound if these conditions are not met. Thus, to further this, the base of the arm must be rigidly coupled to the surface of the platter. It does this through the bearing, and we are just hoping that whatever bearing we have is good enough. As far as the plinth is concerned, it has to couple the base of the arm to the bearing as rigidly as possible, while at the same time being completely dead. My work with our model 208 proved this to be a very audible aspect!

FWIW, anyone familiar with motorcycle or automotive issues will recognize this mechanical principle as it is the same one that requires that there be no mechanical play or flex between the steering and the wheel on the road, otherwise the vehicle will handle in a dangerous manner.

The plinth of the stock MkII does not take this into account- the arm is mounted on a completely different material. The plinth and the arm base thus have two different resonant signatures; any difference will manifest as a coloration.

Now, we might have the issue where the plinth and arm base are made from a single part, but with vibration the base of the arm is out of phase with the bearing mount; this is why I say ""as rigidly as possible**. As we all know, with LP reproduction we are always talking about microscopic movement and this is an area that the Technics engineers did not, at the time, have sorted. So it is my opinion that in order to get the best performance out of the 'table, that a custom plinth built to accommodate the needs of the Technics would be a very cool thing to build. It would be heavy, but cool.
Silverprint, I have not done the listening tests necessary to have a valid opinion myself, but the prevailing opinion is that some coupling between tonearm base and bearing/motor is preferable. IOW, those designs you may see with the tonearm mounted separately from the bearing/motor/platter or deliberately decoupled from it seem to get criticized by those who have heard it both ways. What Ralph is saying, I think, is a little more extreme in terms of advocating a specific rigid physical coupling between bearing and tonearm. I actually cannot imagine how to do that with an SP10 or most DDs, because the bearing is of necessity surrounded by the motor assembly. Ralph, please correct me if I'm misrepresenting your view.
Thank you Atmasphere, one of the things i am mostly uncertain was if the arm base should be coupled to the motor or somehow decoupled (ie. arm base on its own, more or less, as you see in many differnt designs). I appreciate your point of view.
I've listened to the MkII for close to 30 years now- one of my best friends bought his new. It is very nice, but at least in the case of his machine there is one flaw that both of us have noticed- the plinth does not include the mount for the arm, which is on a separate surface.

It happens to be a fact of good 'table engineering that the platter bearing and the base of the tone arm must be as rigidly coupled together as possible. The better the coupling (and overall deadness) in this area, the better, and its the sort of thing that you hear immediately.

IMO/IME, a plinth that was designed for the MkII with this in mind would yield huge results, assuming that it was in fact rigid enough and dead enough.
I have a Monaco Grand Prix Turntable, with a Graham Phantom, I have a Technics SP10MkII in an Oswalds Mill Audio slate plinth (by far the best plinth material for any DD or idler drive). Both tables with the same arm and cartridge display almost identical sonic characteristics. Black background, amazing speed control, fine detail retrival, strong bass. What they both do not do is speed and dynamics like an idler. My Stainless steel Garrard Inspiration, again in an Oswalds Mill Audio slate plinth eclipses both the superb DD's, by a margin. In terms of musicality, speeed, dynamics, soundstage, and bass, I have only heard Mr Fremers Continuum, compete. Mine has a touch more groove noise in between tracks, I think? I now use the Garrard 501 on a wall shelf with Symposium rollerblocs in between. My arm of choice now after trying almost all the major contenders, is the RS Labs A1!
Lewm, if your slab is cut then you will most likely beat me to the punch. I still have to get mine cut...
Cpk, If you beat me to it, let us know how it sounds in slate. My slab is sitting on the floor in my living room, but a little thing like needing to write a chapter for a medical text is keeping me away from installing the SP10 into it.
Well it’s denser then wood but not as dense as slate. ART made a footer type thing with it that had a brass insert, I still have a couple floating around. I would say make it thick enough that the overall weight of the plinth is significant or do what ART did and add brass to it. My concern would be that IIRC the graphite is somewhat brittle and may be chipped easily.

I just got my SP10 today and will be putting it in a slate plinth at some point in the near future..:-)
Dear Dgarretson and Lewm,

Thank you for your promt reply! But i think i shall avoid a probable misunderstanding. I am talking about graphite block, not carbon fiber. The density of the material is about 2.2 g/cm3 ie. 0.08 lbs/inch3. So not very heavy, nor light tough. It is made of heavily pressed carbon powder, its structure is amorphous. It is available in different densities and hardnesses.

As soon as possible I'll try to post a sketch, so it will be easier to understand each other.

Again many thanks
I think one of the advantages of carbon graphite would be constrained layer damping effects achieved by varying material thickness and directionality of carbon fibers. This is how it's done in bicycle frames to obtain strength where necessary as well as lightness. The resonant signature of the material could be varied throughout the construction-- which might have interesting if unpredictable effects unless computer modeled.
Silverprint, As far as I know, graphite has some excellent qualities for audio use, but I don't think it's very dense. In other words, the weight per unit of volume is not great. Therefore graphite might not be so good for mass loading. This is not to say that it could not be useful in building a plinth, but probably in conjunction with other more dense materials, like hardwoods or slate.
Hello everybody!

I am new of this forum. I am writing from Tuscany, Italy, where i live. I happened here looking for info on how to build a plinth for the SP10 MKII. I went quickly to the posts and there's already so much information that I must first of all say thank you to everybody.

My SP10 is flying here from Australia just now, i got it on ebay (from a respectable seller) a few days ago. I hope it will arrive safely...

I think that building a plinth is great fun! Also nice that all SP10 will look very differntly!

I've seen Albert Porter's plinth on soundfoutain and ordered there the template. So now I am working on the plinth project. I really liked Albert's ones (except a few minor hestetical choices), and I will probably work on the same ideas. Specifically i would like to ask you all if some of you has experience with graphite (carbon block) as a mean to add mass and dampen resonances. I can acces a cheap source for this material as well as a CNC machine to work it, so i wondered if it could be of any use.

Meanwhile, thank you again.
Pryso, Thanks for that input. I was unaware that the rod in Albert's plinth actually goes thru to the bearing housing. Very ingenious. So you're correct; that IS different from what Raul has done. You've given me some food for thought; a similar device could in fact be placed under a slate plinth.

Raul, As regards your remark that the SP10 MkII and III may not be the best of their contemporary Japanese brethren, that may or may not be correct, but the point is moot, since those tables are so rare and unavailable. In any case, I would bet that any of them would also benefit from re-thinking the plinths they came in. In many cases it was a big hollow wood box, a nice box, but still a box. Last time I visited my son in Tokyo, I saw a mint Yamaha GT2000 sitting on the floor in an audio salon. Sadly, it had been promised to another customer. The price was actually quite reasonable, about $1500, I think. Anyway, the subject of this thread is the SP10 and its variants.
Lewm, the plinth is made of a combination of solid birds-eye maple and brazilian rosewoods. I did not weigh it, but based on my gym workouts, ha-ha, I figure around the 40lb mark +/- 5. My japanese lead plinth for my TT-101 is about the same at 20Kg.

I have tried it with various cones, no cones, sorbathane and the sprung version just seems to have better clarity and defintion to my poor ears. In that sense the SP-10 plinth then is a combination of mass loaded and sprung isolated. Interestingly the japanese heavy leaded plinth was designed as far as I can tell from surfing Asian websites for either Sony, Denon or Victor direct drives and I have sen a Garrard 301 also on one. I used to live in Asia and still travel there now on business and if I have time look / shop for audio goodies.

My floor is carpet on ply on sub floor nailed to concrete in a purpose built H/T & Audio room in the basement. I don't particularly suffer from floor resonance but would also prefer to have the turntables isolated on shelving attached to the wall if I could - another project waiting to happen!

Steve
Lewm, allow me to reiterate my understanding of both Albert's and Raul's designs, having communicated with them. This may stimulate their responses if I misunderstood either one.

Albert installed a brass rod that attaches to an iron block at the bottom of his plinth. The rubber plug on the bottom of the protective pan under the table has been removed to allow the rod to firmly contact the bottom of the spindle bearing housing, thus draining or sinking away vibrations.

Raul installed the three AT footers under the pan itself. Since the pan does not touch the spindle housing, his system provides an overall suspension.

Therefore, Albert's system is high mass, with a design to specifically sink motor/bearing vibrations. Raul's system is low mass, designed to firmly suspend (pneumatic) the entire tt system. So I think they defined very different endpoints.
Dear Hiho: This Sp-10 comes ( from original owner: not me. ) with a square 1" MDF attached to the SP-10 up square plate where ( right side ) the tonearm is mounted, not very orthodox but works fine.

Regards and enjoy the music.
raul.
Dear Radical, I had the impression from your first description that your SP10 plinth was made of some kind of metal, which is why I suggested you try wood or slate, not because I thought the mass was too low. So, what is it made of, in fact?

Raul, you and Albert may have arrived at the same endpoint in different ways. In Albert's wood plinth (which can be seen on the Sound Fountain website), he employed a steel rod that is threaded so it can be tightened against the bottom of the SP10 chassis. That rod is also attached to a dense metal block at the base of the plinth, so as to drain energy from the SP10 chassis. In a way, that achieves the same end that you achieve by sitting your chassis right on the three feet. I am trying to figure out how to do something similar with a slate plinth.
Raul, you still have not explain how you mount your tonearm. Care to tell? I am all ears.
Raul, if you cruise around the vintageknob website you can see some great DD tables from Japan in the 70's and 80's. All of which attract horrendous prices these days if you can ever find a good one. As an indicato,r one of supposed greats is the Sony PS X9 - and recently I acquired a PS X-70 as a cheap and cheerful table for my upstairs second system and while I am sure it is not in the same league as the big Sony, you get a flavor for how good these decks and arms can be.

Here is a quote off the vintageknob website (a good place to cruise around and experience the feelings of audiolust):

"Myth has it that there were only fifty PS-X9 ever made but that is myth and myth only - even if not as succesfull as Denon's DP-100M or Pioneer's Exclusive P3a, many X9s found their way into radio stations and in a few audiophiles' rigs. I know of someone who has critically listened to all of the usual suspect (L-07D, DP-100M, Tt 1000, PD-555, SP-10mkIII, EMTs et al) and finally sttled for his own deck on... a PS-X9."

Interesting ....... As you say Raul, there is no "best" - like art or ballet we should appreciate each for its merits and our own perceptions of its beauty and performance. And like the ballet, audio systems and performance are a synthesis of individual components and the synergies between them. That is why it is so hard to get into rating the performance of an arm, or table or cartridge, because there are usually a lot of variances in the total system. That's why I am suspicious of equipment reviews as a finite mark on a product. I know that in my system, the final sound from a cartridge might be subtly changed by the capacitance of a phono cable.

But you know all that already Raul, so apologies for the Sunday morning philosophy rant!

Steve
Dear Radicalsteve: I dn't doubt on what you posted on the Victor TT-101, I never heard about it but I heard the TT-801 that looks like the Denon DP-80 but with better specs.

Now, for those times the SP-10 was only one of the great DD TT: Denon DP-80/75, Kenwood 770/880/1100, Pionner 70L, Yamaha 2000L, etc, etc.
We are talking on the Sp-10 but some of these TTs are better yet than the SP-10s.

As always IMHO it is not write the last word on TTs: DD, BD or Idler ones, which one is the last word?, very very hard to say because no one is perfect and all of them have its own design advantages and disadvantages too. Of course that the design execution is a critical subject but everything the same it is a very hard and complex " call " for say the least.

Regards and enjoy the music.
Raul.
I should also add some fuel to the fire here ... I forgot to mention that my SP-10 was outperformed by my Victor TT-101 in a very heavy japan designed lead plinth. Unfortunately when I went on a business trip I left the TT-101 on for a week and when I got back it failed to go around anymore!

I don't know if it was the the table or the lead plinth that made the difference, but the 101 was just sublime. I might just try the SP-10 in the lead plinth next week - but that is a major decision to cut out the lead to fit the Technics.

Anyone have any ideas what might have burnt out on the circuit board?
Dear John and Shane: About mats I'm testing with the SAEC SS-300, Audio technica AT666, Sota Acrylic, Audioquest, a carbon fibre one and a self propietary/design blend materials one.

I have to say that with all them I have good performance but with our mat design and the vacuum from AT is where I like the best, I'm not finish about because I'm trying not only with different mats but with different clamps too.

There is no picture on the SP-10 set up but it is so easy: three Audio technica pneumatic footers ( AT-616 ) directly at the square metal TT base, that's all.
Btw, in my AS TTs I'm using the same kind of footers with additional metal large tiptoes ( up side down ) that are the one that are directly to the metal plinth on the AS, I test the same configuration on the SP-10 and was awful/bad for the quality performance. I try too with two plinths that I own ( heavy ones ) but IMHO with out plinth is how my SP-10 performs better.

Of course that this is not an " absolute " and that's why I say: try it and be the judge in your own system.

Btw, other than to up-date the caps it is interesting too to change all the internal/external power cable.

Regards and enjoy the music.
Raul.
Lewm, my plinth would qualify as a CLD heavy plinth (50lbs) a la Johnnantais so I am not sure there would be much benefit from anything much heavier, but a slate job would definitely look nice - it is something I might think about.

I believe if the Oracle is set up properly, which is not that difficult, it can be incredibly open, dynamic, with a big soundstage, and truthful in pitch. Some say it is a bit ligh or dry in the lowest bass registers - which is analagous to the same characteristics I found in my old Quad 63's. I put that down to accuracy or quality over quantity. Anyway, I cheat, because if I want more low end I just turn up the volume on the crossovers on my transmission line loaded woofers!

I also find the SP-10 is also very accurate in the low end, no bloat or overemphasis here.

One of the great virtues of the SP-10 in a heavy plinth is that it seems to be agnostic to different tonearms and makes every kind of arm perform as it should. I did not find any particular synergies or mismatching with various arms I have tried. My old Triplanar worked nicely as did a Fidelity Research FR64x. Based on the arms I put thru their paces I would settle on the Dynavector 507 Mk2 as being a really good match.
Lewm

I am using the NOS machine for nearly 4 months now with no problem. It is indeed NOS. I was the first to remove the plastic baggies around all the parts taped shut with that anti-tamper green sticky tape. It was like pure sin.

I realise that the RB300 arm is not the best.
Lonestarsouth, Read the thread for an answer to your question. One person here sold a Walker Audio Proscenium after he got his SP10 MkII up and running in a custom wood plinth. This suggests that a properly set-up SP10 is competitive with anything out there. But the same is true of Lenco and Garrard, IMO. However, consider too that the tables have different characters, and one person is not necessarily going to agree with another on which is "best".

Also, if your SP10 is really NOS, you might want to put it on a Variac and bring the voltage up very slowly at start-up. The electrolytic caps in your unit may need replacing or at the very least they need to be treated gently at first. They are ca 30 years old and have never been charged up. Applying full voltage could damage the caps and also damage irreplaceable parts that they subserve.

Radicalsteve, I am very surprised at your slight preference for the Oracle among the three tables you've compared, but you obviously know what you're doing. You might feel differently if your SP10 was in a proper slate or wooden plinth. Do you have any plans to try that?
Nice thread - I am the proud owner of the SP 10 that John "sold locally" that has the working strobe! The table came with this very heavy metal Mcurdy plinth and I have the table screwed into the top of that plinth, dispensed with the very large Mcurdy frame and set the top plate and table into heavyish plinth of rosewoods and maple, with an arm board arrangement that is mechanically isolated from the table. I can swap arm boards in a flash. I will endeavor to put up some pics this weekend.

I have experimented with various mats and use either an SAEC SS-300 metal maat or a very rare Audiolife gun metal mat that weighs 10 kilos and was originally designed for the Micro-Seiki RX 5000. This mat gives high rotational stability I imagine, BUT - I am concerned that the significant weight might strain the motor, although on start up the high torque of the SP 10 shows no sign of stress and it hits full rotational speed as fast as without the mat. I also found that the table performs best with total isolation from the room and to this end the heavy plinth can sit on a sprung subchassis arrangement, similar to the AVID or Oracle tables. I am convinced the sprung system is superior to the heavy plinth on cones.

I can compare my SP-10 with a Micro-Seiki RX 5000 and a recently acquired Oracle Delphi MkV anniversary model with turbo. They are all discernibly different different, no winners, but if pushed I would say the Oracle is the most all around best - but it is frustrating that you can only use light 9" arms on it - I use a Dynavector 507 Mk2 that I used on all three tables for comparison with either a Sony XL-55 Pro, Technics 205 Mk3 MM, or ZYX UNIverse SB copper coils.

Based on the comments here I need to call John and get my SP10 power supply caps updated as well -joint Ottawa project John?

More to follow - have to hit the (ski) slopes now
Raul

I don't see any photo of your SP10?? Can you post one?

Do you actually have a plinth or how do you site the tonearm??

regards
Raul,
I'm curious to know more about the mat you are using, and maybe some of the ones you have tried,
Thanks,
John
I recently got my hands on a NOS Tech SP-10 mkII. How does it measure up to other current high-end t/tables?
Dear Lewm: Something about the Sp-10 plinth: in the last 10 months I heard at least seven Sp-10s ( MK2/3 ) in different systems and with different plinths with different kind of performances I heard all them with good quality but in no one system heard a SP-10 that performs better that mine ( due to the plinth ) that is almost with no plinth at all.

Mine is not very good looking but is a winner, if like me you are looking for quality performance IMHO maybe you should try with and with out plinth before decide which path to go. Yes, like always is system dependent but I think is worth the effort.

Pryso, by accident I test one of my Sp-10s with and with out strobe and I have to say that I can't detect any difference but this was in my system with that Sp-10. What makes a difference is the mat that you use on it.

Regards and enjoy the music.
Raul.
Thanks, I will get some McGyvered Screws made up this weekend. I had the SP10 Plinth made for me , it is a "standard" Russian Birch Ply/MDF type.
I am Comparing this SP10 creation to The RS Labs Arm on an older plinth I had made for a Lenco L75, to the right of this SP10, I have a 301 with 3012 MKII arm in a Simple Plinth (Its a layered Ply/MDF also)
I like all three of these Turntables and have had them in one plinth or another for many years. The L75 is in it's 4th plinth, the 301 is plinth version II and the SP10 is in Version 3, My system pics show version 2 of the SP10 with racing stripe - Yikes!! It's first version was the Original McCurdy Plinth with about 300 lbs mass and a Rega tonearm. While using that SP10 I found I really liked/preferred the big DD tables versus some of the other turntables I had used (Sota Sapphire/Vacuum/SME IV and VPI TNT Jr , Linn and a few other Belt drives ) Then Came the Lenco Challenge that offered me a view of the Idler wheel phenom., and the 301s came last after one very fortuitous Summer were I found one for $25 and two weeks later found one in the trash! Really!
I find the Garrard 301 to the most beautiful Vintage turntable. This latest SP10 Plinth came about because of the FR64S arm that I found this summer (Garage sale too, but I had to pay Non Garage sale price for it...) I wanted to do my best Plinth yet and really give the SP10/FR64 the platform it deserved. So I had this plinth built with strict instructions to keep the look Simple and wanted close 100 lbs mass. Early listening to this SP10 prove that it will be World Class in Performance but the cost has been VERY Reasonable, I cant imagine equaling this TT with a Modern purchase for anywhere near the same money.
Nice! Did you make the plinth?
I've seen repro SP10 platter screws for sale in sets of 3 on eBay, but not in recent weeks. Check it out, anyway. Maybe Albert has a better lead. Failing that, you can probably fashion some using the proper metric screws plus a piece of tubing or metal stand-off to create the sleeve over the threads. Check McMaster-Carr for odd metric stuff.

When you say your SP10 is "very good", what are you comparing it to? I see an RS-A1 sitting on something over to the left.
OK Lewm,
I need 2 screws for an SP10 Platter. Does anyone know where to source some or alternatives??

Here is my new SP10 MKII, in a 80 lbs plinth, black ash veneer, simple. It sounds very good but the cartridge is brand new so it will get better. But I'm excited about this TT, I'm using a cheap Lentek Step-up (battery operated - made in the UK in the 80's) into my Audio Research SP16 phono section. I'll be looking for a suitable /affordable Step-up for the SPU if anyone has a suggestion!

SP10--FR64S--SPU
Thanks, Albert. As far as I am concerned, this could become a miscellaneous SP10 thread, in which any relevant info to the care, feeding, and resuscitation of these great tables could be discussed. So no worries about hijacking.
Lewm
Albert, Assuming I ever could find a Mk III, does it too have an oiled bearing, and does it require a shipping bracket for transport?

There is no ship bracket but the platter must be removed before transport. Oil goes in the spindle at the top edge. There is no easy "marked" oil hole like on the MK2.

If you go to Sound Fountain:

http://www.soundfountain.com/amb/sp10page.html and scroll down about half way, there is a photo showing where oil goes on a SL1810. The SP10 MK3 is the same place.

Before anyone asks, I choose Mobil One 5-30 for both my Technics. Mobil One is synthetic, so it will mix with whatever was there before (if any) and no issues with gunking up.
Strobe adding noise? Wish I understood more about electronics to judge if this is likely.

KAB offers a strobe disabler switch for the 1200 series tables. In response to my questions on this idea for the SP-10 series, friends with electronics knowledge scoff at the idea saying it is such an overbuilt and sophisticated design that disabling or switching out the strobe would not have a sonic impact.

So, anyone here who has actual experience with this mod to share with the rest of us?
Just wanted to say that my SP10MKII is up and running, Thanks to my friend Jean for drilling my armboard (and making the plinth!) The Fidelity Research FR64S with a new SPU Classic GM E MKII is a nice combo on this set-up. My FR64S also has the B60 VTA adjuster , very nice. I will update the photos for my system as they are very out of date.
Albert, interesting point about the strobe and noise, I may just leave it disabled! But I do want to get a Tech to update the caps, Thanks all, and sorry for Hijacking this thread, Just seemed like a great place to ask some SP10 questions,
John T
Kmccarty, I know of such a tech, in the Washington DC/northern VA area. He is highly skilled and of very high integrity. Consequently, he has a backlog of work for 6-8 weeks at all times. (He's got my Mk II now and previously did my Denon DP80.) If you want more info, please contact me via e-mail.

Albert, Assuming I ever could find a Mk III, does it too have an oiled bearing, and does it require a shipping bracket for transport?
Microstrip.

The two voltages responsible for operation, +5 volt and +32.5 volt are the only important ones. The strobe is not necessary and most people agree it only adds noise.

I wonder if it would improve performance of MK2 if a tube circuit were designed to replace the stock Technics supply?
The SP10 MkII power supply has three voltages +5V, +32.5V and +140V. The 140V supply is used to power the strobe light. It is simple half wave rectifier circuit using a single diode, protected by a 315mA fuse - always check fuse F3 before anything else.
Does any one know of a good tech who can change out the capacitors since I wouldn't know a capacitor from a diode? Also, does anyone know of a tech comfortable with cleaning out and replacing the old bearing oil?
Schematic is available either from Vinyl Engine or from a pay site. (I can't remember where I got it.) If you're knowledgable, you may be able to read it yourself. I build tube stuff all the time, but I cannot make out what's going on in the SP10 schematic.
I have never replaced the caps, when I got my first SP10 about 10-12 years ago, It was in a McCurdy Plinth with some strange broadcast arm. The strobe did not work on it, so I began a several year hunt for a strobe. I found one on Ebay (remember the good old days on Ebay?? 1997-8!!) You could find anything there!!I never did try to replace the bulb assembly, my tech did not want to open the SP10 up. I never imagined it was a problem in the Power supply. That SP10 got sent down the road as I jumped into some other mad Turntable project. It was not until the last two SP10s that I started to suspect it was some kind of Power supply issue. Somewhere in my basement is an SP10 strobe!?
Thanks Lewm, I will get that PS looked at this week. Is a schematic needed or is it pretty obvious/straight forward?
John T
The answer to your question about whether or not the power supply governs the strobe function must be "yes", based on your own observation. It's most likely that the power supply supplies a voltage to the circuitry that runs the strobe. If that voltage is not present, the whole strobe circuit would not work. If it's as simple as that, repair should be no big deal. Have you replaced the electrolytic caps in the power supply? In a Mk II, if they have never been replaced before, then they are at least 25 years old. That's ancient for an electrolytic cap and maybe failure of one of those caps could account for your problem. Does the PS that can't power up the strobe still work properly for all other functions?
While we are talking about SP10s, May I ask SP10 MKII owners a question??
I have a Strobe question. I had 2 SP10 MKIIs and two Power supplies. I sold one of each locally and realized that only one of the power supplies allowed the strobe to function??? Does this make sense??? Both Strobes worked, but only with one of the power supplies. I ended up giving my local buyer the combo that allowed a working strobe. So my question is this, has anyone had the experience of a none working strobe under these circumstances?
Am I correct in thinking that the Power supply controls the strobe?? IF it does a competent tech should be able to look at my PS and spot the issue??

My SP10 MKII project will finished tomorrow (Hopefully), It is a Heavy Ply/mdf Plinth with Black Ash veneer, a Fidelity Research FR64S with a New SPU Eliptical.
Cant wait, Thanks in advance.
John T