DC Upgrade for Gyro.. or not

[Sporadic]

Hello,

I have an older gyro with the papst AC motor, but no PSU.. So I either have to upgrade and get the new DC motor, and HR PSU, or look for a new AC PSU.

I have seen some PSUs which would seem to work, like the Martin Bastin Wave mechanic.

There have been many comments on these forums about the various differences between the older AC papst and the new DC versions - so I am interested in confirming the real differences.. i.e. between the AC motor with a quality PSU and the top DC motor with HR supply.

Is the difference just in the externally heard noise of the motor - or does it impact significantly on musical reproduction too?

I would quite like to keep the AC motor - but as it is not dissimilar money to either go to a new top DC or upgrade the AC, I don't want to be paying for markedly inferior sound reproduction..

Would people please mind commenting on whether they think I would be wise to go full DC or upgrading my AC?

Thanks for your help

[Sporadic]

Just an update - the Martin Bastin wave mechanic will not work as it outputs just a regular mains voltage level, rather than the 19V or so that the papst needs..

So it is really down to a custom AC PSU costing maybe 500 GBP, or a new DC motor and HR psu, costing circa 500 GBP..

So is there much in it?

[930 turbo]

If Michell can supply you w/ a 110v Wall wart power supply for your AC papst motor use the VPI SDS.It works in my Gyro/Orbe. Maybe its a cheaper upgrade than the DC motor and the Never connected power supply. The SDS is regularly available in the used market.

[blakep]

Just an update - the Martin Bastin wave mechanic will not work as it outputs just a regular mains voltage level, rather than the 19V or so that the papst needs..

So it is really down to a custom AC PSU costing maybe 500 GBP, or a new DC motor and HR psu, costing circa 500 GBP..

So is there much in it?

Not sure exactly how this would work for you as we are 120V 60hz in Canada vs. 220/50 in the UAE but here goes.

I was in the same boat as you and struggled with shelling out significant money for either a used QC Supply or spending even more on a new DC motor and power supply.

I was reading a post in the Vinyl Asylum by Harry Weisfeld from VPI on the benefits of running the Papst AC motor (he has an older Empire) off a variac and reducing the voltage following startup. This is actually one of the major things that the VPI SDS does as well.

In any event, I purchased an inexpensive variable voltage regulator to give it a try. The Gyrodec simply plugs into the variac. I turn the table on at full power (120V) and once it is up to speed I dial the voltage down to 60V. The turntable is speed consistent at 60V and there are definite sonic improvements. Hard to describe but definitely a lower noise floor-a smoother, less distorted and less grainy presentation overall. I was quite surprised. As you reduce the voltage you can actually feel the vibration decreasing on the motor housing of the Gyro and hear less motor noise. The effects of those reductions in noise and vibration are audible.

Drawbacks of this are its "manual" nature, unlike expensive power supplies like the SDS, Linn Lingo and Naim Armageddon which drop the voltage automatically following startup. With the variac you need to drop the voltage yourself and then turn it back up following shutoff (or before if you prefer) so that you'll be able to start the table up again. If you make an attempt to start the table with the voltage reduced, it will not start.

In any event, a very effective and inexpensive tweak. About $50. I've linked to the unit I purchased (the least expensive model at the top of the page). Definitely worthwhile IMO. Probably not as effective as a very expensive power supply but the laws of diminishing returns are probably at work with those and/or the DC motor and upgraded supplies for it. I have no desire to spend any more money until the AC motor completely dies.

http://www.kelinginc.net/VariableACOutputTransformer.html

[Werner]

As you reduce the voltage you can actually feel the vibration decreasing on the motor housing of the Gyro and hear less motor noise.

If the Papst is audibly noise then it seems time to have it services. It will likely be quiet after cleaning and lubricating. These motors are virtually indestructable.

"manual" nature, unlike expensive power supplies like the SDS, Linn Lingo and Naim Armageddon which drop the voltage automatically following startup.

As the Armageddon is a transformer in a box it cannot do this trick.

For a sketch of a DIY Armageddon specifically for the Gyro look here:

http://www.tnt-audio.com/sorgenti/gyroqc_e.html

As for the DC route: there is not quite the need to buy the HR. There are plenty of DIY recipes for DC motor controllers on the net. Some are even decent.

And Michell's basic DC supply really is good enough to get you started. A basic DC setup will sound at least as good as an AC motor, especially when the latter is old and unserviced.

[blakep]

As you reduce the voltage you can actually feel the vibration decreasing on the motor housing of the Gyro and hear less motor noise.

If the Papst is audibly noise then it seems time to have it services. It will likely be quiet after cleaning and lubricating. These motors are virtually indestructable.

"manual" nature, unlike expensive power supplies like the SDS, Linn Lingo and Naim Armageddon which drop the voltage automatically following startup.

As the Armageddon is a transformer in a box it cannot do this trick.

For a sketch of a DIY Armageddon specifically for the Gyro look here:

http://www.tnt-audio.com/sorgenti/gyroqc_e.html

Don't really know exactly how the Armageddon, Lingo and SDS work but my understanding of them is that they do indeed provide lower voltage to the AC motor following startup. Both the Linn and the SDS drop to around 70V following startup and I understood the Armageddon operates on a similar basis but perhaps I am wrong on that.

Wouldn't say that my AC motor is any noisier now at 120V than it was 25 years ago and it has been lubricated regularly in that time period. As I said, I really embarked on this after a recommendation on this online from HW at VPI who has done the same thing with his Empire. It has worked for me and I ended up actually giving him a call personally to thank him for the idea.

The proof is in the result as far as I'm concerned. The "noise" from the motor which I've described is more of a very slight "whirring" audible from the motor if you essentially place your ear right up to it during operation and it has done that since I've owned the table in the mid 80's.

Reducing the voltage substantially reduces, if not eliminates, that whirring and results in much lower motor vibration which, as I said, can actually be felt on the motor housing. I'd expect that a substantial part of the performance enhancement that supplies like the SDS, Lingo and Armageddon achieve is attributable to exactly this.

As I said, using something like this involves an extra step in record play, but for $50 it has been a no brainer for me.

[Dubmart]

I upgraded my motor to DC several years ago so can't really remember specifics as to how it sounded compared to the AC motor, but I definitely thought it was a worthwhile upgrade, I had the power supply in the perspex box, can't think what it is called now. If I recall correctly getting the HR was a much more obvious upgrade.

I'd say get the DC motor, hopefully it will improve the sound and then you have the option of a further upgrade with the HR.

[Spinnr]

Dubmart.

Called a GyroPower. The upgrade is a stunning improvement.

Vinyl forever.