Turntable power supplies

[duficity]

What is the difference between all these expensive power supplies that are being sold as upgrades to already very expensive turnables and a regular wall wart 24vdc transformer you can buy at Radio Shack. In an attempt to get my turntable running to check it out, I bought one of the RS ones, hooked it up and to my amazemend, it ran. Checked with the strobe and it was rock solid at both speeds. Played an album and it sounded fine. So what would a $1000 plus power supply do extra and how does it do it? Or why couldnt you use any number of hospital grade power supplies that provide the correct voltage? Am I missing something?

[bastlnut]

hallo,

just go listen to one, or get one on loan to listen with your turntable,
and then you will know.

regards,
bastlnut
_________________
little things matter, but make my jaw drop. PLEASE!!!!

[analogous]

There need not be any difference.

You want the PSU not to sag, to have little ripple and low resistance.

[Conrad Hoffman]

It depends on what kind of motor and power supply the turntable already has. For example, my Thorens 295 uses a low voltage stepper/synchronous motor and an internal oscillator to generate the two necessary waveforms. The 16VAC from the wall wart is rectified and filtered before it feeds the oscillator circuitry. A fancy external supply wouldn't do a thing for it. I can vary the incoming voltage and frequency over a rather wide range, with no effect on speed, noise or anything else. There will always be the argument that I haven't actually tried a $1k supply and therefore can't know for sure, but about $10k of test equipment on the bench strongly suggests it would be a waste of money *in this particular case*. If you have a table where the motor is running directly off the wall wart, an external supply might make sense. A good parts supply and some DIY skills would put it in the $50 region- I'd never consider spending much more than that.

[duficity]

I guess thats my question. As long as the power supply supplies constant and steady voltage at the specified level, it seems that it is doing its job. I mean, does the power supply do anything other than maintain the turntable speed at the correct rpm, with no flutter or wow. If so, isnt it doing all the job it was intended to do, or is there something else I am missing?

[Conrad Hoffman]

The "something else" would be how well it can do it. Nothing's perfect and, as audiophiles, we're obligated to latch onto whatever imperfections might conceivable exist, and fret over 'em. What particular motor/tt system are we talking about?

[caligari]

[Conrad Hoffman]

Ah ha! I have similar feelings about another firm who engages in excessive legal action and threats, whose name suggests a large smelly All Hallows' Eve troll.

CH

[Alec124c41]

There is a difference between a complete power supply, including regulation of voltage and frequency, etc., and a wallwart that supplies the voltage to the controlling circuitry of the turntable.
If your turntable has an external source of DC voltage, and the rest is on an internal board, then a decent regulated power supply would be quite adequate.
The Linn Valhalla etc are a completely different kettle of fish, converting AC to DC, and dividing a frequency supplied by a quartz oscillator to out through an op-amp to drive the motor. The whole thing can be replaced by a Hercules or Lingo to some benefit, apparently.

Cheers,
Alec

[andyr]

[Alec124c41]

AC to DC, then generation of a quartz-generated AC signal to drive te AC motor, independent of mains variations.

Cheers,
Alec

[Edmond123]

That is my experience,
Once I visited an audiophile who had been addicted to vinyl for many years, he upgraded his Oracle turntable with SMEV, VDH colibri, venture Phono cable, MC4...etc. But his Oracle turntable still used wall charger for motor, you can't queries the sound play back in texture, and resolutions, however, it was lack of depth and width. All images messed up between two loudspeaker. We tried another LP12 turntable with decent PSU, only with ITTOK II, shelter 501, the resolution and texture is far behind his Oracle set up, but width and depth out bid the $10,000 turntable. I believe you can get a decent PSU for your turntable at reasonable price. Specially AC motors. The theory is same as CD player, any device with motor spinning, the PSU is crucial to its performance.

[andyr]

[duficity]

I have a number of DC motor turntables, like my Oracles, that use a wall wart DC supply and have internal circuitry, just like that unmentionable brand. In fact, I have tried the Oracle supply on it and it works fine. My question is whether there is some other issue besides speed stability that is addressed by the fancy power supplies that would affect the sound. I mean, isnt that all we expect from a turntable is to turn the record at a given speed reliably and without extraneous bearing noise or vibrations and without wobbling around?

[Conrad Hoffman]

On the surface, that's all that should matter, but supplies can also generate RF, have leakage currents and waveform distortions. I do believe that RF can create subtle audible problems if it gets into the wrong places. Wall warts typically have no ground pin, so they tend to be a conduit for all sorts of bad stuff. Ferrites are a good idea, as is a filtered power strip. I can imagine a tt with internal filtering and regulation circuitry (like mine) sounding different/better with a different power supply if there's an RF or isolation problem, though mine has shown no such sensitivity.