An alternative DIY turntable philosophy

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I know there are already two recent DIY TT threads open, but they each seem to be headed in very definite directions.

In the earlier of the two threads Lenin proposed the Pink Triangle Anniversary as a model for turntable design, but this was ignored by subsequent contributors, with the exception of one who claimed that firstly that the PTA's sound was a matter of taste, and secondly that it was in some fundamental way inaccurate.

Now, I am a long-term Pink user, being very happy with my PT TOO, except for one or two foibles of the design which would be fixed by upgrading to the Anniversary. I would take issue with the opinion that the Pinks' sound is inaccurate. I have many years' personal experience of comparisons with other decks and other media. From this, and also from my widespread reading, I would maintain that the Pinks are neutral by design, and are also widely described as neutral by comparison with master-tape recordings (both by Pink and by reviewers).

I am very much taken by the Pink philosophy, which seems to involve primarily:

a) A continuous mechanical loop between the cartridge, via tonearm, subchassis and bearing, to the LP. This means that the materials have to be chosen carefully, and breaks in the path (certainly including the felt mat on a Linn/Roksan-style steel platter) should be avoided where possible. This is the reason for Pink's (patented) use of an acrylic platter;

b) Use of lightweight materials for subchassis and platter, particularly the Aerolam subchassis. This avoids what is generally referred to as "energy storage"; and

c) Optimum damping to constrain ringing within the loop.

A further feature of the Anniversary (which to my knowledge is unique) is to place a very quiet DC servo motor on the subchassis itself, to remove the main problem with most suspended-subchassis decks - namely, the compliant linkage from the motor (on the plinth) via the belt to the platter (on the suspended subchassis). This at a stroke removes the main subjective shortfall of the PT TOO (and others such as the LP12), which is a slight pitch instability.

Now that Pink Triangle have passed into new hands, it seems unlikely that a new "official" PT deck will appear. I gather that Arthur Khoubesserian did not consider even the Anniversary to be the ultimate step along this line, though I can't speculate what he might be working on now that he isn't formally with PT any more.

I would have difficulty justifying the financial outlay for even a second-hand Anniversary right now, but I do have a strong DIY addiction. Does anyone out there have ideas about building their own Pink-style deck?

Alex
 
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Pink philosophy

Viewed in isolation, the Pink philosophy is very good. You have a heavy (acrylic) platter, impedance-matched to the (vinyl) record, fitted to a very light (Aerolam) sub-chassis, slung on a compliant suspension. Thus, the dynamics are dominated by the heavy platter.

Except some fool bolts a pick-up arm (of significant mass) at one corner of the sub-chassis...

Apparently, the (quite substantial) SME V doesn't work well on this turntable. I would be intrigued to know whether light arms such as the Mayware Formula 4 are OK.
 
"Apparently, the (quite substantial) SME V doesn't work well on this turntable. I would be intrigued to know whether light arms such as the Mayware Formula 4 are OK."

That's not the impression I have - Pink used to supply the TOO and Anniversary for review with the Series V as standard (though I did see one in a review with a Graham on it). Paul Miller's group tonearm test in one of the UK mags back in 1989 or so found the SME V on a TOO outclassed an Ekos on both the TOO and an LP12 (so much so that he bought this combination for himself!). He certainly didn't prefer the Naim Aro on the TOO. Miller asserted that the ulra-rigid SME suited decks like the Pink with its lightweight, rigid design.

I use an SME IV on my own PT TOO, and it was a huge upgrade from the RB300, though I can't say I have listened properly to the V on a Pink.

I gather that the Naim ARO and Morch DP6, both relatively lightweight unipivots, do indeed work well on the Pinks.

I do remember a dealer telling me a few years ago that he felt the Series V was too heavy for the suspension of the PT TOO, although Pink used to adopt the Michell method of supplying armboards of different weights for different arms - the one I use under my SME is considerably lighter than the one that was on my Too when I bought it with a Rega.

Yes, I agree that minimum mass is preferable for a tonearm, but this is difficult to achieve at the same time as the required rigidity. SME aimed for rigidity, offsetting the increased mass by using magnesium for the arm in the IV and V.

Pink have at least one started to design a tonearm of their own, but stopped short of a commercial release. I would be intrigued to have more details of these projects!

Alex
 
Alex M said:
A further feature of the Anniversary (which to my knowledge is unique) is to place a very quiet DC servo motor on the subchassis

Not so unique, and not the first. Try a Dual CS-5000 for prior art when you want a quiet DC motor example, and the CS-5** series for an, er, not-so-quiet implementation.

Incidentally, I have an experimental Gyrodec in my garage
with a subchassis-mounted DC motor. The experiment is still in the lab phase, but I learned already that rigidly mounting the motor, even when it is quiet, is not the way to go.

Are you prepared to butcher your TOO ?
 
Ah, but I'm not in your position of being able to get "spare" TTs - firstly Pink don't make them any more, and secondly I don't have any personal connection to the company... :).

Actually, someone over on AA has indeed done this butcher job on his TOO, and claims a substantial improvement:
http://www.AudioAsylum.com/audio/vinyl/messages/112229.html

There is the odd TOO that comes up second hand in the magazines - if I had the odd two hundred quid or so I might be tempted to get a second one for experiment (and I have a spare RB300 lying around that needs a home...)

Alex
 
I concur with your findings Alex

As a Pink Triangle Anniversary user myself, I must agree with Alex that this range of turntables are breaythtakingly neutral.

So neutral, in fact, that questions of which arms work best are a red herring. If a combination of Pink Triangle and arm 'X' sounds bad, then presuming correct installation and set up, its the arm you are hearing, very possibly for the first time. Having tried just about every 'super arm' before settling on SME myself.

I understand that the arm design was a parralel tracker, by the way, designed to complement Pink's 'once and for all' final statement on vinyl replay.

Werner, from a technical pont of view, ridgidly mounting the motor to the subchassis is is the way to go. decoupling the motor from the subchassis will go some way toward minimising noise in the loop, by starts to steer one away from the idea of the motor, belt and platter having a stabe and fixed relationship.

Turning to your Gyrodec problems, presuming you have managed to source a quiet enough motor (as I'm sure you are aware these devices are created far from equal) I would suggest you address the issue of belt tension. this is an area which received a great deal attention in the PT designs, I understand.

As to Dual's 'prior art' - Are you quite sure the CS 5000 had a subchassis mounted motor?:scratch:
 
Re: I concur with your findings Alex

Lenin said:
subchassis is is the way to go. decoupling the motor from the ...

Turning to your Gyrodec problems,

As to Dual's 'prior art' - Are you quite sure the CS 5000 had a subchassis mounted motor?:scratch:

Of course it is .

My rigid-GyroDec problem is simply the fact that I lack time for working on it. Already figured out the belt tension thing, among others.

Yes, the 5000 has a sub-mounted motor. My sister still has one.
It was a very silent motor, although I feel that with aging it gets noisier.
 
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