Showing posts with label Linn Sondek LP12. Show all posts
Showing posts with label Linn Sondek LP12. Show all posts

Monday, 14 November 2016

Building A Custom Plinth For A Thorens TD 150 Mk II


About eighteen months ago I picked up a shabby-looking Thorens TD 150 Mk II turntable. It came with an SME 3009 Series II Improved tonearm (fixed headshell) which was missing its rider rod, the rider weight and fingerlift. I paid £210 for the whole shebang - about what you might expect to pay for the arm on its own. I soon got hold of the missing components for the arm, but the turntable sat neglected in its tired, ugly plinth until May of this year when I finally gave in to the urge to prod it with the pretty stick.

Vendor's ebay photo of my unloved Thorens TD150 MkII

The original plinth on the Thorens TD 150 is, to my eyes, inadequate - both structurally and aesthetically - for such an iconic turntable. This particular one was in a particularly scruffy state. I figured that, if I could make a picture frame (which I can), then making a new plinth for a turntable shouldn't be beyond my limited DIY skills. Next stop, ebay, where I found some pre-planed lengths of American Black Walnut.

20 mm-thick American Black Walnut

Concerned that I'd forget which parts of the turntable's innards went where when piecing it all back together, I took dozens of photos of each component from every conceivable angle before beginning the process of dismantling the turntable. You can't be too careful!

The TD150's innards

It took me a while to work out that the screws that secure the turntable to the plinth are located under the aluminium top-plate on the Thorens. And even longer to find out how to remove the top-plate to get at them. Uncharacteristically, I didn't resort to brute force, but searched patiently online for a solution. It turns out that the upper and lower plates of the TD150 are held together with double-sided tape. Its grip showed no signs of having weakened with the passing years, but heating the aluminium with a hairdryer liquefied the adhesive on the tape and allowed the two plates to be slowly and carefully prised apart. Slowly, because the thin top plate could easily crease or bend if rushed.

Using a hairdryer to loosen the grip of double sided tape

I fitted a new blade to my mitre saw in anticipation of the walnut being heavy going, but nothing could have prepared me for the iron-like density of this timber. This is why the DIY gods invented power tools - shame then that my mitre saw is powered by sweat and expletives. It did the job though - eventually. A framers' guillotine was then used to remove wafer-thin slices of walnut from the mitred timber to ensure a good clean, accurate join, and the parts were glued and clamped.

Assembled plinth glued and clamped

For simplicity's sake I made the plinth with the same internal dimensions as the original, albeit with higher (90mm), and thicker (20mm) sides. With hindsight I should have made it a few centimetres wider to accommodate a larger armboard and to give the SME tonearm a bit more room to breathe, but that's a minor quibble.

Once the main body had been assembled and clamped, I used the triangular off cuts that resulted from cutting those 45 degree mitre joints to brace and strengthen the plinth. These were cut to an appropriate length and glued in place. After allowing 12 hours for the glued joints to dry, using the layout of the original plinth as a guide, I cut lengths of 10mm pine stripwood and glued and nailed them in place to provide the necessary support for the top-plate. Once dry, I dropped the turntable into its new plinth and - surprise, surprise - it fit.

Trying the plinth for size

The next stage was to use fine sandpaper and wire wool to give a really smooth finish to the timber. Once the surface was prepared, I applied natural Danish Oil with a cloth to bring out the beauty of the grain. I allowed six hours' drying time between each of the five coats and used a fine sandpaper on the plinth between applications, finally buffing with a cloth to give a warm satin finish to the wood.

Braces and batons

Corner brace

Building up the layers of Danish oil

I replaced the original flimsy baseboard with a piece of 6mm MDF. This improves the structural integrity of the plinth and, as a result, the sonics of the turntable. I could probably have used an even thicker piece of MDF, but that's something that I can easily change down the line. I discarded the original black rubber washers that were masquerading as feet and opted instead for height-adjustable conical metal spikes. They look great and make the turntable easy to level.

Conical turntable isolation foot

I drilled two holes in the rear of the plinth for the power lead and arm cable. On the original plinth the leads were fed through holes in the baseboard, but I was looking for a tidier and more elegant finish. Then I went to work on the platter,  giving it a thorough going over with T-Cut metal polish before buffing with a soft cloth. I opted to keep the original arm-lowering knob on the turntable, even though it's disconnected and surplus to requirements, because, well, why not! It lends balance to the over-all look.

Ideally, I would like an armboard made from the same walnut as the plinth. I've earmarked a piece with a particularly attractive rippled grain, but I don't have the right tools to accurately cut the timber. For now, I'll make do with the original armboard, even though it's looking past its best - not helped by the fact that I used acetone to clean off some dirt and sticky residue and removed part of the black lacquered finish in the process!

Piece of walnut earmarked for the new armboard (with the original)

I recently acquired a new platter weight, with integral spirit level, from a seller in Germany. I had to adjust the suspension on the Thorens to allow for the added weight, but it sets the turntable off nicely and tightens up the sound.

Platter stabilizer weight with integral spirit level

The SME came fitted with an ADC 10E MkIV moving magnet cartridge when I bought it. This is a great little cart, but I have no idea how many hours are on it, or how it had been treated by its former owner. The fact that he was using the arm without the rider weight may hint at the stylus having uneven wear. Being incapable of leaving my equipment alone (!), I had to try a Moving Coil cartridge on the Thorens, just for a comparison. Unfortunately, it sounds so damned good that I don't want to take it off. I had intended using it with my Linn Sondek, but am having second thoughts now. The cartridge in question is an Audio Technica AT-F5 OCC. And it's lush!

Audio Technica AT-F5 OCC and disc stabilizer

At some point, I plan to have a  Perspex dust cover custom-built to finish the turntable off. For what was intended as a cheap back-up turntable to play some of my more beat-up records, this is turning into a rather serious project. The performance of the TD150 since I nursed it back to health is beyond anything I could have imagined. I'm beginning to understand why so many people hold these turntables in such high regard.

Linn Sondek LP12 alongside Thorens TD150 MkII

Thursday, 7 February 2013

Audio Technica AT95E Cartridge

I recently installed an Audio Technica AT95E cartridge in the tonearm of the Technics SL1210 in my second system: the latest move in an ongoing struggle to find a cartridge that doesn't make me want to scuttle out of the room into the welcoming arm of my Linn Sondek. I had always believed everything I read about how the Audio Technica carts are glassy and shrill in the top end - not a sound that I wanted to inflict on my ears - but the sub-thirty quid price tag on the AT95E and the following it seems to enjoy amongst budget-conscious audiophiles persuaded me to give the cart a chance. What an inspired decision that has turned out to be!


Mrs Shelf-Stacker has now completely abandoned any pretence of appearing even vaguely interested in my hi-fi. She likes much of the music that comes out of the speakers, but the tune is all that matters to her, not the quality of reproduction. A micro-speakered iPod dock, her iPhone, a musical greetings card or, God help me, the piece of crap, black plastic, stacking 'hi-fi' system that she provided as her dowry, it makes no difference: she is incapable of distinguishing between the sonic qualities of a decent hi-fi set-up and these instruments of torture. She's happy just so long as they're rattling with the effort of farting out The Number Of The Beast or For Those About To Rock. You know that look you see on someone's face when they are singled out for attention by a slurring drunk on the Tube? That's the look that crept over my wife's facial features when I began to explain my enthusiasm for the Audio Technica cartridge. So, I'm sorry, I'll just have to tell you about it instead.


My second system, for many years, consisted of a 1990s-era Marantz PM-44SE amplifier (now the heart of the kitchen system, banging out Peppa Pig CDs and the like), a Marantz CD player, a Technics SL-1210 MkII turntable with stock arm sporting a procession of cartridges (Shure, Stanton, Ortofon) and a pair of Wharfedale Modus Eight floorstanding speakers. The Marantz amp combines clinical iciness with a complete absence of tone controls, ensuring that some CDs can scalp the unwary at fifty metres. The Wharfedale speakers were surprisingly punchy all-rounders but with the build quality of an Ikea wardrobe. They served me well, but I shed no tears when they left to be replaced by a truly wonderful pair of Ruark Prelude speakers which have clearly been created by otherworldly craftsmen.



Hankering for a more analogue-friendly system, I experimented with an older, aluminium-fronted Marantz Model 1050 amp before falling for a Quad 44 pre-amp / 303 power amp combination. The fact that Pink Floyd supposedly used Quad 303s in the studio during the recording of Dark Side Of The Moon was enough to pique my interest. Their robust, Cold War, Eastern Bloc, utilitarian, nuclear submarine instrumentation-evoking appearance just adds to the appeal.




The stock arm on the Technics was long ago discarded in favour of an Origin Live-modified Rega RB250 tonearm, but still I couldn't get the sound I wanted from my vinyl. I was left completely unmoved by the highly-regarded Ortofon 2M Red cartridge which seems designed to mimic the cold, soulless, perfunctory aloofness of CD. Even a vintage Ortofon Turbo MC1 moving coil cartridge left me scratching my head and wondering if perhaps I was simply expecting too much of my Technics turntable. Years of tinkering have taught me that a component that sounds pedestrian and lacklustre in combination with one set-up can come alive elsewhere. My beloved B&W DM14 speakers sounded dire hooked up to Marantz amplification, but sang when teamed up with my Audio Institute valve amp, so perhaps the 2M Red will, in turn, find its perfect partner somewhere down the line. What I do know is that the Technics is a joy to listen to now that it has been mated with the AT95E.



Where is the harsh, glacial reproduction that I was expecting? The sound is beautifully balanced: a clear, revealing top end recreates subtle variations in cymbal tones that were completely ignored by other cartridges, whilst the bottom end has bass extension and an analogue warmth and richness that has been hitherto lacking. The mid-range lacks some of the detail of the Ortofon MC15 Super MkII cartridge installed on my Linn Sondek, but I wouldn't expect it to match the performance of a significantly more expensive cartridge. Shure's Trackability Test Record will put any cartridge through its paces: the Audio Technica can't cope with the bass drum low-frequency trackability test, but the sleeve notes on the Shure LP state that it would be "a near miracle that any cartridge could successfully track" that test. The Ortofon MC15 aces it, but it is an exceptional cartridge.



In the real world though, away from the unrealistic demands of Audio Obstacle Course test records, the Audio Technica tracks well and, with the limited hours I have put on it, doesn't seem to provoke sibilance or inner groove distortion. Straight out of the box the cartridge is a doddle to set up and performs superbly even before it has had a chance to run-in. The bottom line is that I am finally able to sit back and enjoy listening to records on the Technics deck without comparing it unfavourably to the Linn Sondek. Thirty pounds well spent!