Turntable PSU

[Rare Bird]

I'm a bit out of touch with turntables but i need some recommendations for a real world power supply to use with a 48 pole AC synchronous motor TT.. Just thinking back to the old Flutterbuster but can't remember!

[DSJR]

Why not try a simple mains filter rated at 6A. A lot cheaper than designer transformers or external supplies, but may just keep the worst of vibration inducing interference at bay?

http://uk.farnell.com/roxburgh/pmf6/filter-in-line-6a/dp/1101097?Ntt=RoxburghIN-LINE

[Reid Malenfant]

cheap 50W per channel amplifier, decent sized electrolytic capacitor, 18V 60VA transformer & an accurate 50Hz sine wave generator & you have a TT power supply.

Or if you want call it a regenerator :)

[sq225917]

The inline filter linked to will do nothing for improving the speed stability of your turntable, it filters at Mhz frequencies and does nothing at all for the noise that your motor will be susceptible to which is typically from DC to about 1khz.

Your options are a transformer coupled filter of suitable size, which is more likely to be 500va than 100va or less. Or an active regenerator that turns your AC to DC and then back again. The Hercules is the most price sensible of these options, but it most certainly is not suitable for a 48 pole motor, and will need modifying to give you the correct phase delay for your particular motor.

You may not like either of these options but they are the only ones that aren't pissing money up the wall.

[Rare Bird]

Simon
I understand the filter has nothing to do with speed stability.. however regardless of my over obsession for vintage equipment, it may come as a suprise to some that i know jack sh*t about Hi-Fi & find all these technicalities go over the top of my head, hence id rather scrap the who idea all together tbh & just listern to my records.. :)

I'm one of these guys: if i buy a product that for example has a cheap mains cable, i'll replace it with something that looks to be of higher quality & also looks pretty, i'm not intrested in it's specifications or claims over sound improvement :D

[hifi_dave]

Why not try a simple mains filter rated at 6A. A lot cheaper than designer transformers or external supplies, but may just keep the worst of vibration inducing interference at bay?

http://uk.farnell.com/roxburgh/pmf6/filter-in-line-6a/dp/1101097?Ntt=RoxburghIN-LINE

Is that like the Croft filters we used to fit to everything back in the 80's ? Because they made a big difference to the sound of every turntable we tried, lowering and cleaning up the noise floor.

Back then, Glenn couldn't make them fast enough to keep up with the demand. We had customers buy one and then come back next day for more, even fitting to ELS speakers and TV's..:D

[blake]

One of the most important, if not the most important, things the Linn Lingo, VPI SDS and Naim Armageddon do is substantially reduce the voltage to the AC motor following startup.

This, in turn, reduces motor noise and vibration which, when transferred through the belt, degrades performance.

You can achieve similar results (albeit with an added step that takes a couple of seconds every time you play a record) with a simple variable output transformer which costs about $50 or 30 GBP.

Not sure about the numbers on your side of the pond. In North America, voltage at the wall is about 120v and the Lingo and SDS drop down to around 68-72 following startup.

I've implemented this idea with my Michell Gyrodec with very positive results after Harry Weisfeld from VPI suggested it for older tables with Pabst motors like the Empires (Harry has operated them with good results off a variac in the past) on another audio forum.

I was considering a used QC supply or an upgrade to DC but haven't really thought much more about it since buying the transformer.

[sq225917]

Is that like the Croft filters we used to fit to everything back in the 80's ? Because they made a big difference to the sound of every turntable we tried, lowering and cleaning up the noise floor.

Back then, Glenn couldn't make them fast enough to keep up with the demand. We had customers buy one and then come back next day for more, even fitting to ELS speakers and TV's..:D

No nothing at all like it.



The Armageddon doesn't drop the voltage rails after start-up. It doesn't need to do this because they spec the correct cap value of 0.2uf as opposed to the 0.22uf everyone else uses to drive the second leg of the psu. Because they spec a capacitor that doesn't give the correct 90 degree phase lag it causes the motor to stutter ever so slightly and they have to drop the voltage to reduce it. Some of the designs make it even worse by supplying a different voltage to each phase- so in effect applying different torque to the motor at every second pole of its revolution.

If you supply the correct phase lag and equal voltage you can run the Premotoec type motors at 110-120volts and still get faultless noise and speed stability performance. Especially if you add a little drag... ;-)

[DSJR]

I know where Simon is coming from, but still own and use the Croft made 4A "Pi" filters. The Roxburgh at £52 started life (to my knowledge) as the £200rrp Chord Co Clearway. I tried them and liked what they did - similar to the Croft and best used one per item..

Back to Andr'e's situation. An Armageddon style supply will cost methinks. My thoughts were that the filter is cheap, works for me (I use several) and, if the deck didn't benefit, a CD player almost certainly would, that's all...