Technics SP-10 MkII spruce-up

[pete_mac]

Something abnormal is going on here at Casa Del Mac - I'm suddenly over-run by Technics turntables! First, my new SL-120, and now a SP-10 MkII that a Mexicano SNAer asked me to inspect, caress and rejuvenate where possible.

The legendary SP-10 speakers for itself, so there's no need for me to copy and paste the usual guff here. However, I will certainly say that it is built like a TANK.

This particular unit is an ex-ABC turntable, and the ABC sticker is still affixed to the casing of the power supply. The power supply was refurbished at some stage in the past, with high quality caps used throughout. The neon lamp is dead though, and this will most likely be replaced with a suitable LED conversion.

The chassis has experienced some corrosion over the entire surface, and has a mottled 'salt and pepper' appearance. It is quite smooth to the touch though, so it may have been cleaned, sanded and polished at some stage. It would be a prime candidate for refinshing in future. I foresee a factory silver or satin/gloss black finish on the horizon (although I could be very wrong!)

First things first... let's unbutton her!

Platter removed:

Cast alloy baseplate removed (some minor marks here, but you won't see it once it is mounted in a plinth)

Mmmm... very clean and shiny! All of the PCBs are attached via one main PCB with slotted arrangements, much like a PC motherboard.

Got ICs??? Yup!!

Now, being a Technics/Panasonic/Matsushita turntable, the caps throughout are Matsushita/Panasonic. So, I've endeavoured to use Panasonic caps during the refurb where possible.

First board removed (including the quartz locking circuitry)

Old caps:

New caps:

Second board removed - this one features regulators on a aluminium heatsink which attaches to the chassis. To access some screws, the power supply connection point must be removed:

Old caps at various angles:

Now... remember how I mentioned wanting to use Panasonic caps only? Well... I've finally ran out of my supply of 1uf Panasonic FC caps, and Panasonic 1uf caps are getting hard to find at short notice! I have some nice Nichicons coming tomorrow, so these will have to do. They're Japanese, so the underlying heritage of the turntable will be largely unaffected

The third board only had two capacitors - one of which was an axial 100uf 50V. I had some short, fat Panasonic radials in stock, so I decided to fit these rather than trying to source a 100uf 50V axial of lesser quality. It fits well, and a dab of hot-melt glue will be affixed to provide mechanical stability for the long journeysouth of the border.

Out comes the centre-most 'motherboard' PCB:

There's one solitary cap on this board:

All of the boards are now removed. Behold the semi-naked SP10 MkII!

This design makes extensive use of metal stand-offs to mount the PCBs:

We can now see the date that the motor was manufactured:

Still to come... fitting the dastardly 1uf 50V Nichicons, reassembling the turntable, checking, cleaning and lubricating the bearing, checking the brake mechanism, adjusting the PLL circuit which relates to the speed accuracy of the turntable, and fitting a replacement LED to the PSU. Watch this space!

All the while, I'm copping nasty glances from a certain beast which is part of a large multi-unit resto project currently underway. I can understand why... my blood used to be pure black, but suddenly there has been an influx of silver! It's hard to believe that a Sansui has been booted off the bench!

[Deano_malaysia]

Nice job brother very cool to see inside the beauty, I would like to say if the owner doesn't want it back them consider her sold to me 😀

[unclemack]

Great work there Pete.

 

Fascinating to see the electronics in this beast...

 

Cheers

 

M

[Tasebass]

Geeeessss......there's some components under that hood!!!

[hochopeper]

Very nice!

[Gordon Macfarlane]

Thanks for sharing Pete.

[Sierra]

You're right @@pete_mac ... she is "spotless under the hood" ... and in excellent hands 

No oxidation at all on the inside which is great to see ... means the electronics haven't been exposed to anything nasty over the years.

I was wondering what it's vintage was ... '87 was a good year ...

 

I didn't realise the base plate was made of alloy ... from pictures I had just assumed it was made of plastic.

 

 

 

Nice job brother very cool to see inside the beauty, I would like to say if the owner doesn't want it back them consider her sold to me 😀

 

Fat chance of that happening my friend!  

 

It will be coming home to Melbourne ...

[cafe67]

As a owner of a full sl1000mk2 , those piccies are great , very formative so thank you lots :-)

[Sierra]

As a owner of a full sl1000mk2 , those piccies are great , very formative so thank you lots :-)

 

Very Nice!!

[woadl]

Thanks for the post

Now I know what to do with mine

Cheers

[pete_mac]

OK, let's check out the motor and bearing/thrust plate!

Here's the motor assembly with the top black cover removed:





And the electric brake assembly in all its goodness. This is in immaculate condition - I've seen some horrible photos!




The grey high density foam rubber insert is removed:




Then the brake assembly (VERY carefully!)




Then the black plastic cover:




To remove the top of the motor assembly, we remove the two screw on the metal retainer assembly:




We are then greeted by this lovely sight!




She's very clean overall. The thrust bearing pad is in excellent condition with only a tiny dimple. The owner and I agree that it can be retained. It looks worse in the photo than it actually is - it really is a tiny shallow indentation.






You can find some incredibly BAD examples of these thrust bearings out there on the internet - many have worn all the way through! For example:

 

 

The lower bearing cap is also removed. This involves heating the assembly with a hairdryer to loosen the thread sealing compound, and then removing the cap by had with a suitably grippy towel or jar-opener.






The ball bearing is removed by tapping it firmly with a suitably sized piece of dowell. DO NOT use a metal implement under any circumstances!

The bearing assembly/shaft/well is thoroughly cleaned and reassembled. The best approach to lubricate the bearing is via the bottom of the assembly. This avoids the likelihood of trapping air around the bearing, which is problematic due the extremely fine tolerances within the assembly. You will find that the motor assy will 'float on air' if you try to lubricate the bearing well from the top, and then drop the motor assy in. There is simply nowhere for the air to escape! Once appropriately lubricated with approximately 5 drops of oil, you sit the ball bearing in position and re-install the bearing cap by hand. This process re-seats the bearing inside the bearing shaft without requiring blunt force (it is an extremely tight fit!).

I didn't get any pics of this last part of the process, as I was doing my best to juggle multiple components and oil at the same time. There just wasn't time! I did, however, take a photo of my initial 'probing' from the top side of the bearing well. There was very little lubricant between the thrust pad and the ball bearing, that's for sure! Quite dry, thick and discoloured. She's MUCH better after the service!


 

 

Anyhow, we are getting closer! The final capacitors should arrive tomorrow (as I was not home today when the courier called in... boooooooo!)

[evil c]

You're right @@pete_mac ... she is "spotless under the hood" ... and in excellent hands [emoji14]

No oxidation at all on the inside which is great to see ... means the electronics haven't been exposed to anything nasty over the years.

I was wondering what it's vintage was ... '87 was a good year ...

I didn't realise the base plate was made of alloy ... from pictures I had just assumed it was made of plastic.

Fat chance of that happening my friend!

It will be coming home to Melbourne ... [emoji14]

Oh - so I've been following your turntable's rebuild !

Pulled out your wallet, dusted it off and splurged on a Mac refurb - well done ! [emoji4]

[Deano_malaysia]

Wow still so impressed how clean she is inside, amazing

[Sierra]

OK, let's check out the motor and bearing/thrust plate!

The lower bearing cap is also removed. This involves heating the assembly with a hairdryer to loosen the thread sealing compound, and then removing the cap by had with a suitably grippy towel or jar-opener.

Looking great Pete ... the more bits you pull apart the better it looks inside.

Apart from the speckled finish on the outside of the chassis it's looking in really good condition for it's age everywhere else.

Hope your wife didn't mind you borrowing her hair dryer

 

 

Oh - so I've been following your turntable's rebuild !

Pulled out your wallet, dusted it off and splurged on a Mac refurb - well done ! [emoji4]

Haha ... yes you have ... do you feel cheated now?

Nothing but the best with a Mac refurb

[pete_mac]

The final chapter - she's ALIVE!! <cue thunder, lightning and maniacal cackling>

 

The caps arrived to complete the final PCB. The unit was then reassembled, fired up, and connected to the oscilloscope for testing and to undertake the period adjustment as per the service manual. Both settings were out by a bit, but they are now in spec.

 

 

 

 

Now, bear in mind that this unit will be fitted into a new plinth, possibly resprayed, and cleaned up in general. It still presents very neatly indeed and apart from the uniform marking on the alloy surface and a few scratches on the power supply casing, she's in decent nick overall! The matt (if retained) will also come up beautifully well with a wash and soft-bristle brush.

 

 

 

The original power globe was dead as a doornail, so a LED conversion in retina-searing Chinese Blue was undertaken to match the illumination of the owner's gear. This could easily be changed at any stage by soldering-in a standard 3.3V 3mm diameter low power LED of  whatever colour.

 

 

 

 

The original strobe and speed illumination functions perfectly, which is amazing regarding the strobe after all these years. 

 

 

 

The bum:

 

 

 

Gratuitous bum close-ups:

 

 

 

 

Cool ABC sticker!

 

 

 

Platter removed - note the heavily damped underside:

 

 

 

Balanced!

 

 

 

Something that's fairly important when shipping one of these turntables - a motor locking bracket. These came with said bracket from the factory, but most are long-gone.

 

I've made up a very simple bracket with aluminium angle and two thin plastic pieces. Ugly as they are, they match the dimensions of the original bracket with respect to the height offset between the chassis and the motor perfectly. This helps to locate the motor properly, preventing it from moving in and out if the turntable is subjected to shock or turned upside down during transit. Simple yet effective.

 

 

 

All that's left is to refit the turntable into the temporary plinth, box her up, and wave a fond farewell!

 

I can't wait to see what @@Sierra makes of it!

 

 

EDIT: the last photo shows the cool strobe set-up. Having seen how the platter has the indentations on the underside of the lip, once the platter is installed you don't see these. You can see a prism at the bottom centre of the photo which provides a reflection of the indentations when lit-up by the flashing strobe. It's a very neat setup!

Edited January 31, 2016 by pete_mac

[soundfan]

I commend you @@pete_mac. A superb job on one of the great DD turntables. 

[Sierra]

I commend you @@pete_mac. A superb job on one of the great DD turntables. 

 

Couldn't agree more!

 

@@pete_mac went above and beyond on this job that's for sure and I can't thank him enough!

 

I bought this TT off eBay from a guy in Sydney and Pete offered to actually go and pick the TT up for me ... saving me the hassle of having to get the TT packaged and then couriered out to him.

This sort of help and support is priceless and very much appreciated.

 

Pete is a perfectionist in what he does ... as is @@skippy124 ... and your audio gear couldn't be in better hands!

[Tasebass]

Utterly superb thread....one of the best I've seen on SNA IMO with respect to others....indeed why wouldn't you join SNA after looking at this...

 

Great Photo's and great story..

 

Makes me wonna go out and buy something just so Pete can fix it!!.....  

 

Brilliant......cheers Tase.

Edited January 31, 2016 by Tasebass

[pete_mac]

Thanks for the kind words gents. Working on this SP-10 MkII was a pleasure

[Sierra]

Just though I'd post a little update on what has happened since @@pete_mac had worked his magic on my SP10.

The motor unit came mounted in this weird plinth with a metal base arrangement which will all get tossed out when I build a proper plinth for it.

But for now I just wanted to play a record on at and have a listen to what it sounded like.

 

The plinth it came in is made of chipboard surrounded by metal strips screwed into each side, with the front and back metal strips bent at a 45 deg angle which then bolted to another piece of metal folded up at the edges to match which then formed the base ... a real strange arrangement.

The first thing to do was to put some feet on it ... so I removed the front and back strips and sliced the 45 deg fold off ir with a grinder and cutting wheel.
With the metal folds out the way I could then attach some basic feet made from some pine baton off cut and some self adhesive rubber feet.




I was originally going to use 4 feet but decided on 3 in the end.



As luck would have it the arm fitted by the previous owner was a Rega ... so my spare RB300 would be a drop in fit ... excellent!
The cartidge is my spare Denon DL-103r ... a bit of measurement for VTA meant that I would have to raise the base of the Rega arm by a couple of mm ... a 3/4" galvanized washer from Masters was the perfect thickness and with a bit of filing to take the 3/4 id out to 24mm ... a perfect fit.

A bit of basic cartridge alighnment thanks to a Vinyl Engine protractor (I don't have a proper cart alighnment tool)



Set the stylus pressure to the recomended 2.5 gram.



And we have music.

 

 

Very nice cart this ... I can see why it has such a strong following.

 

 

 

What I really love about this TT is the speed stability ... it's just spot on.
I can't get over the fact that I can use my record brush now and actually put pressure on it without stalling the platter like it did with the Rega.
No amount of pressure on the brush will change the TT's speed it just remains constant.
You can even put pressure on the edge of the platter with your finger and there is no change in speed the strobe stays constant regardless.
Not even a slight hint of slowdown when pressure is applied and then recovery ... it just doesn't vary ... the torque the motor applies to compensate for any resistance is instant!

The other really cool thing is the platter brake ... when you turn the platter off it stops instantly ... no more having to wait for the platter to stop or help it stop with your finger.
And likewise the startup is also instant.

So how does it all sound?

Damn bloody good is how it sounds!

I was really surprised as to how good this setup sounds, the bass is full and rich but not over done, the mids are nice and open and detailed, the sound stage is nice and wide and the top end sparkly.
It's not as refined as the Rega/Audiomods/Cadenza Black combination, but I wouldn't expect it to be at this point with what it's running.

In the future the Technics will get a new plinth sporting two tonearms.

The Audiomods will be the primary arm with the either the Cadenza Black or the Lyra Delos.
The second arm will be of the interchangeable head shell type which will have the DL-103r in one head shell and another cart that can play 78 records in another head shell.
A third head shell will have whichever of the two carts is not installed on the Audiomods arm.

Will be making a start on the plinth later this year ... but for now I'm enjoying it just as it is 
 

 

 

[pete_mac]

Looking good mate - glad that you like the turntable. She's a beast!

[Sierra]

Thanks Pete ... love the turntable ... a very refined beast for sure 

[Wolfgang Felber]

Hi Pete, great to read this thread on the SP10MK2, I have one that I am trying to fix on my bench at the moment. When I first got it, it didnt work at all. I have now got it to the point the where it runs but at hyper speed. The speed switch works, the voltages are in line with the service manual but the speed is still too fast. 

 

Wolfgang 

[mloutfie]

4 months ago I bought an SP10 mk2a in a decent condition all is working well and I haven't use it a lot in the last 4 months because I haven't got a plinth for it. I've recently made a plinth for it So I spend a bit of time to do clean up and oiling.

After oiling the bearing (2 drops of sp10 original oil) There is some scraping sound so I dismantle and motor and checked the bearing. looks like it's almost dry with some green coloured grease (I assume this is a mixture of the old oil and debris from the trust pad). The thrust pad looks a bit worn (though I forgot to take pictures).  I then cleaned the well and put couple drops of bearing oil directly on the well and resit everything back. the scraping noise is gone right after I assemble (on 33 and 45) but it comes back when I spin 78 and persist when I go back to try 33-45. The noise disappear  again after I lift the bearing and resit it back.

 

I have ordered a replacement thrust pad seeing that it's a clear suspect on why the scraping noise is there I suspect the bearing is just now been hold by the tension of the oil in the well that's why on higher speed the tension disappear. Any one had similar experience like this (ie issues shows itself after re-oiling bearing). I hope the issues gets resolved with the new thrust pad. Anything else should I be looking while waiting for the thrust pad? I assume experience with outer Technics motor is usable also

[krakatana]

@mloutfie

Have you replaced the electrolytics? I'm going through the process now. The caps in the power supply and the logic circuit were particularly bad ie. leaking.