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Snake oil?

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Re: Snake oil?

Postby ef37a » Fri Sep 21, 2018 8:44 am

But, sometimes....

I recall reading many years ago that great claims were made for "improved" turntable mats?

On the face of it, snake oil for sure but, the top magazine of the time HFN published an article about some tests and one of the key factors was that a record definitely sounded different when the turntable unit was acoustically isolated, another room, from the speakers. Even with the dust cover down the stylus/disc "interface" was still sufficiently microphonic to colour the sound.

Then, various mats were used for the "same room" tests and there were definite, repeatable differences and levels of "miccyness" . The mat marketing WAS however a bit of a scam since, iirc, it was a plain 6mm thick felt mat costing pence that won out against the expensive stuff!

Dave.
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Re: Snake oil?

Postby Sam Spoons » Fri Sep 21, 2018 9:54 am

I recall damping the platter of my Sansui 222 turntable underneath with heavy car body damping bitumen sheet, definitely stopped it ringing when tapped and I didn't notice any increase in 'wow' which would have been there if I'd spoiled the balance. As I worked for a piano retailer with a workshop I had easy access to sheet felt and also made a felt mat (cue bad joke "Where do you go to get felt? A piano workshop!"). I still have the Sansui and intend to set it up again in the office as part of a transfer/editing suite for my dance teacher wife (after 40+ years of dance festivals she has music on vinyl, cassette, MD, ¼" tape and CD).
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Re: Snake oil?

Postby Martin Walker » Fri Sep 21, 2018 10:47 am

ef37a wrote:But, sometimes....

I recall reading many years ago that great claims were made for "improved" turntable mats?

On the face of it, snake oil for sure but, the top magazine of the time HFN published an article about some tests and one of the key factors was that a record definitely sounded different when the turntable unit was acoustically isolated, another room, from the speakers. Even with the dust cover down the stylus/disc "interface" was still sufficiently microphonic to colour the sound.

Then, various mats were used for the "same room" tests and there were definite, repeatable differences and levels of "miccyness" . The mat marketing WAS however a bit of a scam since, iirc, it was a plain 6mm thick felt mat costing pence that won out against the expensive stuff!

Dave.


Hi Dave,

Now here I can speak with some authority (just for once ;) ) as back in the 80's I worked in Garrard's R&D lab and performed lots of acoustic feedback testing with among other things a range of turntable mats.

I was using a rig that shook the deck, driven by a mechanical oscillator through the entire audio frequency range, with the stylus in the groove, and getting a spectrum analysis printout of the output for posterity.

Heavier mats definitively damped down resonances (as did extra 'struts' glued into the deck itself at various strategic points, but as always it came down to cost. We (Garrard) were by then largely at the budget end of the market (no more 401's) and heavier mats were more expensive to ship etc. However, the strategic struts made their way into future Garrard deck designs.

We did however use the heavier mats on an OEM model range for NAD, which had a higher retail price.

Fascinating stuff!


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Re: Snake oil?

Postby ef37a » Fri Sep 21, 2018 11:30 am

I remember the 401! Was that the TT with that clever eddy current brake speed controller or was that just the 301?

I seem to recall the Garrad tables were never top choice of the audio cognoscenti because of the rumbly jokey wheel drive.

Thorens were THE machines to have, until the all conquering DD Technics came along.

I could afford NONE of them! I had a BD1 kit, a home made arm and only got as far up the cartridge food chain as the M75e!

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Re: Snake oil?

Postby Sam Spoons » Fri Sep 21, 2018 12:08 pm

I sweat blood to get my system back then, reading all the Hi-Fi mags and researching different kit. I ended up with the aforementioned Sansui 222, a Sugden A48 and KefKit Chorelli's. I haven't read a Hi-Fi mag since ;)
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Re: Snake oil?

Postby Hugh Robjohns » Fri Sep 21, 2018 12:18 pm

ef37a wrote:I remember the 401! Was that the TT with that clever eddy current brake speed controller or was that just the 301?

They both used the Eddy-Current brake idea.

I seem to recall the Garrad tables were never top choice of the audio cognoscenti because of the rumbly jokey wheel drive.


:-) Not sure if that typo was intentional or not... a jokey jockey wheel!

Yes, the jockey wheel drive is a simple design... but actually it really does work remarkably well when set up correctly and with the turntable mounted in a proper plinth.

I have a majorly re-engineered 301 which has been substantially upgraded to incorporate the worthwhile developments introduced with the 401 (but with much better quality control!).

It has a solid CNC-machined brass chassis (rather than the 301's rather disappointing cast aluminium) to give it much more stiffness around the main bearing. The bearing is also heavily upgraded to cope properly with an oversized 10kg brass platter (7kg heavier than the original which was cast aluminium). Apparently, very few of the original platters were ever properly balanced due to casting anomalies, and although Garrard tried to balance them by drilling holes, they remained a source of rumble and vibration.

The desk is partnered with an SME M2-12R 12-inch arm fitted with a Dynavector pickup, and the whole lot is mounted on a very heavy slate plinth with isolating support legs. It sounds superb without any hint of rumble, wow or flutter... and no microphony at all... so you can hear all of the inherent imperfections of pressed vinyl discs perfectly... :lol:

Thorens were THE machines to have, until the all conquering DD Technics came along.

I've had a couple over the years. A 166mk2 was my first hi-fi turntable in 1982, (partnered with a NAD 3020A) and I had a TD160 much later. The whole 'suspended sub-chassis' design with belt-drive is very good, but I much prefer the 301. ;-)

I believe the infamous Linn Sondek was based on the design of the Thorens TD150 and Ariston RD11, although it has evolved somewhat from those 1970s origins (and enjoyed massive price rises along the way). I still have a Linn Axis turntable in my office which is an ingenious budget design from the late 80s that I like a lot. I've also used a lot of Technics DDs professionally, but never really liked them from a hi-fi perspective.

H
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Re: Snake oil?

Postby Hugh Robjohns » Fri Sep 21, 2018 12:19 pm

Sam Spoons wrote:I haven't read a Hi-Fi mag since ;)

Very wise! :lol: :bouncy:
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Re: Snake oil?

Postby blinddrew » Fri Sep 21, 2018 12:32 pm

If I recall from a previous thread, I think there are a surprising number of Sansui 222 owners on this forum (I'm another).
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Re: Snake oil?

Postby Sam Spoons » Fri Sep 21, 2018 12:46 pm

Hugh Robjohns wrote:
Sam Spoons wrote:I haven't read a Hi-Fi mag since ;)

Very wise! :lol: :bouncy:

I went from listening to Hi-Fi systems back to listening to music almost overnight :)

blinddrew wrote:If I recall from a previous thread, I think there are a surprising number of Sansui 222 owners on this forum (I'm another).

For those of us of a certain age it was the magazine's budget favourite back in the day. IIRC We all lusted after a Rega Planar and admired the Linn from afar (financially at least). All were a step up from the Garrard SP25 I had before.
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Re: Snake oil?

Postby Martin Walker » Fri Sep 21, 2018 12:50 pm

I started out with a Thorens TD150 too! 8-)

Garrard had ended up in a greatly reduced state by the time I joined them, and my main claim to fame while I was with them was redesigning and streamlining the motor control circuitry, which saved around 13p per board. I was a hero that week!

Sad but true - by then, saving pennies across the entire turntable range was applauded, as keeping the price competitive seemed the only way forward.

Fascinating job though while it lasted, but then I moved on to Atari and entered a whole new world of computing 8-)


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Re: Snake oil?

Postby Wonks » Fri Sep 21, 2018 1:20 pm

Martin Walker wrote:Fascinating job though while it lasted, but then I moved on to Amstrad and entered a whole new world of shame 8-)
Martin

:o :o :o :o :o
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Re: Snake oil?

Postby ef37a » Fri Sep 21, 2018 1:33 pm

Hugh, that is not a 301 anymore. More like "Trigger's broom"!

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Re: Snake oil?

Postby Hugh Robjohns » Fri Sep 21, 2018 3:01 pm

Yes. Quite right!

It's the same design, though, and still uses many original parts in the linkages and knobs etc, but it is manufactured and built properly, the way the designer had originally intended, rather than being manufactured on the cheap in a way that emasculated the quality of the design. It is a very clever and elegant bit of engineering, though, and quite stunning in its upgraded form.

Interestingly, many of the upgrades on my model are very similar to those introduced by the Beeb's in-house engineering department when they employed 301s in the original RP2/1 studio turntables. The 401 turntable was used in a later version called the RP2/6.

http://www.orbem.co.uk/grams/grams_3.htm
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