Cartridges height

That's true, but I think the change was brought about by lack of availablity of parts for the old one, IIRC.

 

Except of course there isn't a DC motor in a Technics DD...

Paul

 

Sme Psu

SME upgraded the PSU on the original Model 20/30 as they were not CE compliant. So an upgraded unit was made which was CE compliant.

Regards D Louth 77

 

There is Paul.

The SP10MKII uses a brushless DC motor, as does the SL1200. I can't speak for the whole range though. I'm not sure if anyone uses / used AC motors in DD config.

Although not a DD, I think the idler driven Garrard 301 / 401 does use ad AC motor.

 

It's a 'dc' motor in the same way as the SME motor or the Linn motor. IOW not dc...

Paul

 

Paul - you have no idea

 

Is that so? Isn't it a question of interpretation?

Although BLDC motors are practically identical to permanent magnet AC motors, the controller implementation is what makes them DC. While AC motors feed sinusoidal current simultaneously to each of the legs (with an equal phase distribution), DC controllers only approximate this by feeding full positive and negative current to two of the legs at a time. The major advantage of this is that both the logic controllers and battery power sources operate on DC, such as in computers and electric cars. In addition, the approximated sine wave leaves one leg undriven at all times, allowing for back-EMF-based sensorless feedback.

From Wiki

 

Sorry, my electrical knowledge has failed me, what do you mean not 'DC'? As I understand it a DC motor, operates on DC current, an AC motor on AC current, (notwithstanding universal motors used in industry).

I thought the Linn used an AC motor, same as Michell et al used to use. The Lingo produces a precise sinusoidal waveform for the LP12's AC motor.

The Technics PS on the SP10MKII takes in 230v AC and outputs DC to the TT. Can this still mean it has an AC motor inside?

 

Murray

For example, my old Michell Syncro ran on AC voltage with a 24 pole 12 volt AC motor. There was no conversion to DC and just a couple of parts in the chain between wall supply and motor.

My Technics runs on 24v DC current supplied by an off board P/S. Although current can run 'both ways' round the motor, this is to initiate the start / stop motion. It (the motor) only ever 'sees' DC. Technics call it a 'brush less DC motor' and hence I would say it's a DC motor.


Damn, nearly distracted there....

Regardless of AC / DC. The point I was making in my OP was that there is a precedent for outboard PS on various different TT and for different engineering reasons.

Isolation from EMI, More stable / precise feed to and control of the motor. All designed to make your record player better.

Whether you feel that putting one of these on an SL1200 is 'polishing a turd' pretty much depends on whether or not you have heard the difference between with and without. In just the same way putting a Lingo on an LP12 is considered by some reactionaries to be 'polishing a rubber belty turd'. However, the results to some are very pleasing and if you ain't heard it, then you'd be a bit wrong to say so.

There's more than one way to skin a cat etc etc etc.

 

Ironically it's an AC motor that is used as though it were DC...

Paul

 

The electronics inside an SL1200 or SP10 do something analagous. Except it's three phase and has servos and stuff.

Paul

 

Paul

thanks, I still don't understand. What am I missing?

The Lingo produces sinusoidal i.e. AC waveform. Is the Linn Motor a single phase AC motor?

The technics PS does work in three phases. I THINK that's something to do with the quartz oscillator though. Are the three phases are used as comparators to give a more precise and consistent frequency?

The end result is surely that the Technics P/S supplies to the TT 3 lines of single phase (i.e. DC) voltage at:

5 V DC
32.5 V DC
140 V DC

P.S. The service manual is at vinyl engine.

 

I suppose it must do. Why has it taken so long for this paragon of vinyl replay to take its rightful place in the "high end"? It's been kicking around for donkey's years, and everyone's heard plenty of them.

 

I suppose it does have something to do with the onset of recession but there are other factors at play. Most of them benign, I don't think this is a marketing effort initiated by Technics. Although the decline in DJs using vinyl could be construed as a possible factor for that I don't think they think that deeply about it.

1. Rediscovery Many bits of kit have been rediscovered as not quite as shite as we thought (or were told) they were. The Garrard 301 / 401 is a prime example. I wonder how many magazine writers (Noel Keywood maybe, he uses one), would have owned up to having a specially plinthed 301 in the 80's? I think it's commonly accepted now that they produce some very good sounds.

2. The DD approach The re-awakening of interest in DDs as a whole could have been started by the www and the easy access to Japanese / Far east sellers. Most of the higher end machines sold in minuscule numbers over here and there aren't many about. Articles in HiFi world, forums, 2nd hand fairs etc all also helped. With a renewed interest in the method (DD) naturally the revival in interest has trickled down to the cheaper models. Try a well serviced L07-D or SP10MKIII and I think they'd take on all comers.

2. The High End I'm not sure that those at the 'high end' are swapping out their Brinkmans and SME 20a for KABSL1200. However, for the sub 1000 bracket (and probably for a bit above that too). I think it's probably a pretty hard to beat proposition. Cheap 2nd hand deck, Technoarm / Nima, Audio origami re-wire, platter matt, DL304 and some isolation feet, all for less than a grand if you're lucky. Doesn't look great but it's all about SQ isn't it?*




* Not for me, I like my stuff to look okay too.

 

You'll get no argument from me. I can see the point Paul is trying to make but FWIW I'd still regard it as a DC motor.

With regard to the 1210, the basic motor unit is fairly sound. It, like many turntables, benefits from better isolation, a better tonearm than that supplied, some attention paid to the choice of mat used and a better power supply which it is easier to implement offboard. The same can be said for many decks including the equally venerable & venerated LP12 which I think even James used at one time.

Having heard a couple of 1210's thus treated I'd say they can be considered as a relatively affordable alternative to many more expensive belt driven designs.

Its certainly an approach I'd consider now if I was looking to buy a new, good quality record player. There are plenty of ways that huge sums of money can be wasted on perspex & bling which also give a far worse result

 

quote

from psu thread,
i used to work for alphason, when with mike and i worked with what i still think was one of the most super turtables ever design "SONATA along with the HR 100MCS i have dealt with t/t's since the mid 60's as a child, as for your coment on my thred on psu's maybe you should hold on to your thread if you haven't got a decent coment to make i have a resolution to your problem, issu is i charge,
regards .
nando

 

I assume this is a modified SL12xxx? That 24 volts goes directly to an IC which contains drivers and to a subsidiary regulator that produces 9v for the clocks and stuff. I think it's not comparable to what goes on in a Lingo or the SME PSU. That's handled by the IC. Do any of the SL1200 modders dig right into that area?

If you include all the electronics then it's a 'brush less DC motor'. But the DC is very isolated from the motor coils which have AC sinusoids passing through them.

Certainly upgrading the DC supply to the SL1200 isn't analagous to upgrading an LP12 from Valhalla to Lingo.

I suspect the bulk of the benefit from an external supply for an SL1200 is in the physical removal of the transformer and its associated fields and vibrations.

If I hadn't impulse bought an SP10 I was planning to acquire an SL1210 for a project. My thought was to transplant the motor into an alternative plinth arrangement.

Paul

 

To the OP. Can't you just remove the VTA adjuster for this cart?

The AT33PTG is about 16mm top to stylus before tracking force. This seems to be a popular cart that fits most things. So I wonder if you have to re-evaluate your setup?

Paul

 

Having looked at how it goes together I'd guess doing that to a 1210 would perhaps be more trouble than it was worth.

I think an SP10 (or one of the other standalone motors by JVC or Denon) gives more scope to be 'creative' with the plinth!

 

I think perhaps with a new bearing? Just reuse the motor and electronics. One option would be to produce something compatible with the SP10 but new and relatively infinite.

I see from another forum that the KAB SL1210 PSU retains the Technics rectifier/regulator etc. A keen DIYer might just remove the transformer to another place.

Paul