Technics SL-M3 Turntable Repair & Service

Now here’s a deck that got some attention whilst it was with me! For this second #TechnicsMonth article, come with as I repair and service this rare and beautiful Technics SL-M3 linear tracking direct drive turntable.

Do you like awesome turntables, Technics gear and fine furniture? Then you’ll definitely love the Technics SL-M3 linear tracking direct drive turntable! Few have seen a Technics SL-M3 and, as my customers visited to drop off or collect gear, they would see it and go “Oooh” and “Ahhh – what’s that beautiful turntable..?”

Let’s find out more about this elusive deck in my second #TechnicsMonth article. As usual, you can also watch my companion video on the Technics SL-M3, or read on for more.

Bad Timing

The Technics SL-M3 linear tracking direct-drive turntable is one of those classic decks that few people have seen or heard of. That’s mostly due to bad timing, the SL-M3 hit the shops right after CD was released and for those of us that remember the furore, that’s all people cared about for a few years.

Decks like this were released and people just wanted to talk about lasers and unmeasurable wow & flutter. Still, the SL-M3 is a really lovely deck, from a legendary brand. Whilst the build quality is not in the real heavyweight division, it’s still a 15kg well-made turntable with a lovely furniture finish.

A Technics supplied promotional image of the SL-M3.

Features

The SL-M3 has all the stuff people wanted in a turntable just a couple of years before – direct-drive for low wow & flutter, linear tracking for zero tracking distortion and push-button start, stop and track access, just like CD! A nice, heavy platter, great standard cartridge and space-age styling combine to create a pretty compelling package.

In a way, this deck had it all and yet try to find one for sale today and you’ll see the dilemma. This is just one of many little turntable avenues that one can explore and find so much to enjoy. My customer is a linear tracking turntable nut and I’ve also worked on an SL-10 and SL-V5 for him. I think this SL-M3 is his pride and joy though.

Specifications

Type: fully automatic
Drive: direct drive
Motor: brushless DC motor
Drive control: quartz phase-locked control
Platter: 325mm, 2.5kg, aluminium die-cast
Pitch control: +-6% range
Speeds: 33 and 45rpm
Wow and flutter: 0.022% WRMS
Rumble: -82dB
Tonearm: dynamically-balanced linear tracking
Effective length: 238mm
Effective mass: 13g (including cartridge)
Cartridge: moving magnet
Replacement stylus: EPS-33ES
Dimensions: 526 x 205 x 425mm
Weight: 15kg
Made: 1984 – 1988

Problems

This particular SL-M3 came to me, like so many decks, not playing records properly.  The linear tracking mechanism was playing up and the deck would play the first little bit of a record and then get stuck. It sounded bad, the speed adjustment was out and she just needed some TLC.

You’ve gotta love a smoked lid, very cool at the time and still cool now.
You can see the SL-M3 has a furniture-grade wooden plinth, with embedded motor and kind of stuck-on arm control unit.
Nonetheless, it’s a beautiful looking machine and a fine record player, just not yet.
Worth mentioning that the cartridge is a rare Technics EPC-P205C Mk4. This is a moving magnet cartridge, with a boron cantilever and elliptical gem. Great specs and it’s a really nice cartridge. Whilst it’s not one of the best cartridges ever, it is nevertheless a very good MM cartridge. Cartridges like the P205C will crush cheap modern MM cartridges, so it’s worth retipping, as long as the boron cantilever is retained and the suspension is OK after all these years.

Mechanical Service

Someone had unfortunately been here before me and broken the stylus guard. That might have been OK if they had glued the guard back onto to the pegs, and not then glued the pegs into the deck. That part was stupid because to service the deck, the stylus guard has to be removed. It can’t be removed if the pegs are glued in place!

Yeah, to remove the platter, and one must remove the platter to make the adjustments and lubricate the motor, I had to break this glued bond. These pegs are meant to be part of the stylus guard. Instead, somebody glued them into the black plastic assembly. Some might be thinking “why not just unscrew the whole assembly first?” You can’t get it out with the guard in place and without being able to simultaneously lift the platter, which sticks in place, risking arm and cart, unfortunately.
The broken guard. At least it’s in good condition. It can be glued back in place but that glued bond has to be broken again at some point for service. The owner was happy for me to leave it off.
Plan view of the carriage drive and control unit assembly. This is very similar to many Technics linear trackers and needs careful, periodic maintenance to remain reliable, smooth and free running.
This is a standard Technics DD motor, like those found in an SL-1200.
Part of mechanically servicing an SL-M3 involves lubricating the motor. I use synthetic bearing oil, over a period of an hour or more, gradually working the oil into the usually fairly dry bearing assembly, running the deck to help the oil work its way in.
The carriage mechanism has to come apart to really get it working properly again. That involves removing and cleaning this drive rail…
I’ve cleaned the inside of this slide bearing too. I use a special PTFE-based lubricant for these sorts of bearings.
As part of the mechanical service, I replaced the carriage drive belt and carefully cleaned and re-lubricated every worm drive, bearing, pulley and rotor. I also adjusted the lead-in point, which was way out and stressing the tonearm. Doing this properly takes time, there are no shortcuts.
Control panel, with strobe in the background. This is important because…
one way to tell your master speed control needs adjustment is to notice if the speed changes when you press the ‘pitch reset’ button. When the light goes out and you are in manual mode, the speed should remain identical to when it is quartz locked. If it slows down or speeds up, visible on the strobe, you know the reference oscillator needs adjustment.

Electronic Service

Once the deck is mechanically working properly, it’s time to take care of the electronics. There are two adjustments here, one for reference oscillator frequency, which gives us our non-quartz locked reference speed and one for platter braking.

The two SL-M3 electronic adjustment points.
Setting the reference oscillator frequency is not something that the average owner can do, or that many technicians would bother to do. You can see here that I’m using a Tektronix oscilloscope probe…
…attached to my calibrated, ultra-high-resolution frequency counter, which cost as much as a small car when it was new BTW! If you want your deck to run at the correct speed, this really is the way to do it. The correct frequency is anywhere between 262.075 and 262.085kHz. Before adjustment, the frequency was 233. something kHz, which is WAY out! This received a final tweak to put it right on 262.080kHz.
Here we have a test scenario after all mechanical and electronic adjustments.
We are good to go!
The last part, after cleaning and inspecting the stylus, involves playing my test record, through my trusty Sansui AU-317 workshop test amplifier. Everything here sounds good and runs perfectly.

Technics SL-M3 Up & Running!

The final part of the service involves cleaning and detailing and the following images show the deck in all its glory, ready to be picked up. In terms of value, these lovely decks vary a lot in price and often don’t work properly, like this one when it came in. I’ve seen them go for between $1000 and $2000 AUD, so choose carefully and be ready to get a comprehensive and expert service on any old deck like this.

As far as being a unique and great sounding deck though, this is right up there. Just look at this beautiful piece of engineering, all designed to extract sound from the groove modulations on a piece of vinyl. Amazing when you think about it.

After a polish, she looks a million bucks.
Her owner is really thrilled to finally have her working properly.
If you want a nice linear tracker, definitely keep an eye out for a Technics SL-M3.

As always, thanks for stopping by and if you’d like me to shower your Technics SL-M3 or any other Technics linear tracker with some TLC, please get in touch.

6 thoughts on “Technics SL-M3 Turntable Repair & Service”

  1. I have the same turntable. Back in 1991 I was stationed in Germany and my buddy wanted to get rid of it. I bought it for $50! Neither one of us knew what we had till years later when I checked eBay! Still works perfectly and is as beautiful as the day it came out of the factory. Probably needs to be serviced I imagine.

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