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 an Australian audio nutter 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.

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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

 

[pete_mac]

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 journey south of the border.

Out comes the centre-most 'motherboard' PCB:

There's one solitary electrolytic 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!

 

[needforspeed]

A TT I've always wanted, But prices out of reach. Looks real clean. Killer amp, Also nice and clean. A VU meter freak also. Use a pair of Carver M-500's. Can't wait to see final results. Thanks

 

[JP]

I find it interesting to find a motor with such a late date code in a MKII.

 

[totem]

I find it interesting to find a motor with such a late date code in a MKII.

JP what are the commonly found motor production dates for the MKII and variants?

 

[JP]

No idea. My 'Technics by Panasonic' badged MKII is 1978. I have a second MKII badged 'Technics', but I can't remember. My MK2A is NIB in factory sealed bags so I can't check. A friend had two MK2A and they were 1984. I do have a new factory spare motor that is 1988.

I'm not sure when MK2As were officially on the market, or when they ceased production on the MKII, but I'd think it was around '81-'83, so a MKII with a motor dated 4-5 after the MK2A was introduced seems rather late. It could be a replacement, or maybe a custom 'table if they did such things. The blue board tucked in by the buttons isn't found on a main-stream unit either. I'm not very familiar with the broadcast versions though.

 

[Ken Boyd]

I knew recapping my power supply was a must but I suppose while at it I should pop open my table and do the same thing. One question when I replace all the caps is that all that's going to be needed or will I need to have it hooked up to a scope?

 

[JP]

Period adjustment should be done after a recap. Really, it should be done anyway as there's enough component drift after a few decades that it'd benefit from it. If you don't want to do a full recap I'd recommend doing at least C2, 4, and 6 on the drive board as those three take the most abuse. For the same reason it's also not a bad idea to use 100V parts there. Those three caps have no affect on the period adjustment. Actually, none of the caps on the logic board will have an affect on period adjustment either.

 

[best-groove]

Hi guys .... I joined only because by chance I read this thread and as I had just finished these days the total restoration of my Sp 10 II I discovered many similarities to the turntable Mr. pete_mac .... and I'm very excited ....really!

1) First, the engine production date who are twins 21 aug 1987

2 The number of pcb series that are very very close, my pcb have all this issue of serial number 270709

3) the number of the turntable series, the same label gray and fonts equal, instead of the old labels with red border.

4) the type of in / out connector which is not the usual standard connector but it is different as different is to pete-mac.

Having done much research in the past as well I thought the engine had been replaced now by reading this thread but I changed totally my mind.

There are many similar details to the turntable of pete-mac that make me believe that they have been produced about the same time and have not had a change of engine.

I am convinced that our turntables have been in the very year 1987-88 products maybe for some broadcast radio (no BBC) or other institution, but not for private customers; the engines were not replaced at a later date but our turntables were very year 1987-88 products.

Since I discovered all this I think that the search for the truth has come to the conclusion.

Best regards