LP12 Motor and Power Supply suggestions

[dsavitsk]

I have an old LP12 (SN < 3000.) The arm (Roksan) and cartridge (clear audio) are pretty recent, but the table itself has had few, if any, upgrades in 30 years (I am the second owner, but I know it hasn't had any since 1993, and the PS is clearly pre-valhalla.)

I am looking to upgrade the power supply, and perhaps the motor. One promising route appears to be using a DC motor and a well regulated power supply. Origin Live seems to sell kits, but they are a lot more thn I am willing to spend, and I'd rather design stuff myself. Furthermore, designing a variable regulated DC power supply should not be a big deal.

The question, then, is what I should use for a motor. Is it worth just buying a motor from OL? It is expensive (abot $120 for the DC100, and $250 for the DC200), but should fit the table okay. Or, does anyone know a source for decent quality DC motors that can either drop into an LP12, or that can easily be modified to do so.

Any other LP12 upgrade suggestions?

[Nanook]

Maxon and Pabst make some great motors....I'm sure Origin must use one or the other in their tables..

but have you considered reducing the ac voltage going to the stock Phillips/Airpax motors? Apparently the Linn benefits from an initial start up of 110 Volts (full Voltage in North America), but a reduction to 82 Volts(just enough to overcome drag and load while not accellerating) while running presents a considerable upgrade. Also consider seperate ac power supply (Really easy to do --all you need is a frequency generator, a means for attenuation or gain as needed, and a big *** power amp), and ya can alter turntable speed by altering the frequency...., and motor noise by altering voltage out..

Also some time ago HiFi+ magazine from the UK did a comparison of some mods and had recommendations..And might I add a Nuance shelf from Ken Lyons is apparently a very worthwhile and relatively inexpensive mod..

www.neuanceaudio.com

(I am in no way affiliated or own any of Ken's product's)

[dsavitsk]

Originally posted by Nanook
Apparently the Linn benefits from an initial start up of 110 Volts (full Voltage in North America), but a reduction to 82 Volts(just enough to overcome drag and load while not accellerating) while running presents a considerable upgrade.

I'd have a starved motor to go with the stared heaters in my amps. Do you happen to know the current draw to determine the size for a dropping resistor.

Originally posted by Nanook
Also consider seperate ac power supply (Really easy to do --all you need is a frequency generator, a means for attenuation or gain as needed, and a big *** power amp), and ya can alter turntable speed by altering the frequency...., and motor noise by altering voltage out.

Interesting. How much power would I need? Could a gainclone do it or does it take more power?

Also, what is the recommended method of generating a wave?

Originally posted by Nanook
And might I add a Nuance shelf from Ken Lyons is apparently a very worthwhile and relatively inexpensive mod..

Looks nice, but not very DIY.

-d

[Nanook]

A simple frequency generator can be made with a really cheesy cd player and a cd of 60 Hz signal (just repeat the frequency for the entire cd) and a means of attenuating the signal,or make one. I'd have to really check into a complete DIY frequency generator. I think that was posted here or on another forum

The relationship V = IR applies for resistors in an AC circuit , so the voltage of 120 V often has a .117 Amp current draw (for a 14 Watt device). Dropping the voltage would require a 480 Ohm resistor, with a suitable rating so as to disappate the heat without burning up.(if I remember basic electronics correctly). I recall that Neil McBride, on his website (which hasn't been updated in some time), needed first to step down the Voltage from 220V to 120 or 110 Volts.

Try here DIY Armageddon for a power supply. Basically a few resistors, a cap or two and an appropriate Toroid. Often Turntables require very little current, (and hence "Watts" to power, so if using a frequency generator I'm sure a 25 watt single channel Gainglone or similar would be fine)


the Nuence is not DIY, but elsewhere Mr. Lyons suggested an Ikea "Lack" table cut down as a cheap alternative (apparently Target in the US sells a similar table), about $20 USD. Not completely DIY but cheapenough, and still requires a little work.

[Nanook]

basically the same motor system, Airpax Ac Synchronous motor...Systemdekll power supply

[sbrads]

Just for inspiration, I can still remember the extra transparency and deeper bass when I had the Valhalla upgrade fitted to my 1981 Linn a year or two later. Any method that reduces motor vibration ought to boost sound quality.

A mod from HiFi News in the mid 80's was to epoxy a thick collar of perspex around the main bearing to the metal plate, this damped the 60Hz flex mode of the whole assembly and was plainly audible as a more even bass response. I never felt like removing it in the following years, so it must have worked.

[Nanook]

Some time ago HiFi+ magazine did some "buying a used LP12" and LP 12 upgrades", May 2002.

by Roy Gregory and Jimmy Hughes...(I guess if they can or could be considered experts).

Some have suggested that the Valhalla made the LP12 sound spectacular but a little "soul -less", than earlier LP12s . The Armageddon I think brings the soul back. If dsavitsk liked/likes the sound of the original, the Valhalla may be a bit sterile. The dampening idea sounds interesting, and if it worked/works, great. Certainly an easy to implement idea, and reversible...

[Zoodle]

Has anyone tried the Hercules psu? If so, how long have you been using it, and have you had any issues with it? Thanks in advance.