AC vs DC motor?

And there is no one who can share their experience?????

I'd just like to find out if anyone when form a D/c (or A/C motor on their turntable) to the other format. What were the differences? The good and /or bad results?
Is a battery powered motor a pain? Do you constantly have to check or change the battery?
Thanks for your support!

Rwd, I have the Redpoint/Galbier DC motor controller. Prior to that I had a VPI TT with SDS AC controller. The Galibier seems quieter to me with less motor vibration to deal with. My original battery lasted about 2 years and I purchased another for about $65 to replace it. The new one is more powerful and will most likely last longer. The only advantage of the VPI with SDS was that it was easy to dial in and lock the speed with the digital readout. I picked up a KAB strobe which really helps make it easier to dial in speed with the DC controller. Overall I feel that DC is the better way to go.

Thanks Dmailer!! Now were getting someplace! Anymore?

P.S. How did you know the battery was dying? Does it have an indicator light?

I replaced the battery when I noticed that it was not taking on a full charge. The power was depleting rather quick after a charge. It was still working when I stopped using it but I decided to get a new one before it gave out completely. I bought a Vector 450 amp jump starter and it works just fine. A fringe benefit is that you can jump start your car with it if need be.

The old battery had a VU meter. My current one has lights showing the level of charge. As far as use, I leave charging during the week and only unhook from charging when I play music. On weekends when I listen to more music I leave unhooked from the charger all weekend and do not worry about it. There is plenty of juice to run a TT motor for a week or so straight between recharging.

DC motors don't necessarily mean that its power source is a battery, in fact most run off of a DC power source. Why all of this discussion about batteries and none about the advantages or disadvantages?
Again, the advantages/disadvantages boil down to the execution of the design in regulating/maintaining speed.
Bob P.

I have a Platine Verdier, which I used originally with a standard AC supply - very good it was then. About a year ago, I bought a Battery PSU (GT Audio in the UK - www.gtaudio.com) supplying DC power to the motor, and this transformed the Platine - much quieter, less surface noise, greater dynamic range - one of my best ever upgrades. If all DC power supplies are similar, then go for it.

I have an original Oracle which has AC not DC. The later Oracles went to DC and then back to AC. I have a MacMod Box by Mod Squad which is a speed stablizer so it runs at 33 1/3 or 45 rpm. Yup it's the one that started the whole deal with going with the optional power supply for Linn,Oracle,Vpi etc.etc. The difference between DC and AC is AC has alot less tourque and takes time for the platter to get up to speed. With the early Belt Driven Oracles if you were dry cleaning your record with a brush the record could just stop with little pressure. Now this is what i was told anyway and my power supply is plugged into the wall.

Hi Bob P......excellent point..."Again, the advantages/disadvantages boil down to the execution of the design in regulating/maintaining speed" so which one does it better? Most here say...D/C?

Dear Rwd: The ACvsDC is not the issue, because both are good ones it depends what the TT designer looks for.

The name of the game here is " power supply design and execution to that PS design ". The motor well " is a motor " if you give it what is asking for you can't have any trouble and will works fine: both motor designs.

There is no single battery design that can even a good AC PS design. The Topoxford.. experience trhough a battery PS means that the original AC PS was not up to the task not that the battery one is better.

Regards and enjoy the music.
Raul.

I used my LP12 with its origonal Valhalla AC supply, then added an Origin Live DC motor kit. Probably marginally better, BUT don't forget DC motors are noisy, you can hear the brushes even on the best. I have moved on to an Origin Live Resolution/Illustrious, which I have no plans to change. It uses OL's best motor the 200 series and Ultra power supply. The sound is wonderful, but the deck was built for DC supply. As Raul points out, some decks are built with DC in mind others AC. It aint what you do, but the way that you do it. Ultimately it depends on the skill, care and material content of the design. I dont think one is intrinsically better than the other.
By the way, I can still just hear the motor with the current turntable, with the best motor Origin Live have.

'Motor' on over to Audio Asylum-Vinyl Division and ping Mark Kelly. The guy knows way more about motors that you'll need to know, and is kind enough to share his knowledge. He's done gobs of work with controllers, AC DC, etc., and will be able to answer any question.

Great!

Greetings,

The folks who advise you that it's all about execution are right on the money with their advice. In no way have I discounted the concept of AC motors for example - even though all of our current offerings employ battery powered, DC drive systems.

Regarding DC noise - I'm not certain what the poster is talking about. Yes, if you get within a foot of the motor pod, you will hear a bit of "whirring" sound. If this sort of thing makes you lose sleep at night, than I suggest that you to listen do CD's.

Perhaps the poster is experiencing more noise than what we experience here at Galibier. Sometimes, with rigid drive belts, a user can misalign the belt slightly and put some ripples on the belt's edge. This will increase the noise a bit, but can be resolved for about a penny with a new belt.

As far as torque is concerned - one can have high torque AC as well as DC designs. Similarly both AC and DC motors can be designed for low torque.

As far as the design of a turntable's drive system is concerned, torque is one of those parameters which needs to be optimized in the context of platter mass, drive system (belt) compliance, and bearing oil viscosity. Too much or too little torque will sound "off the mark" in one way or another.

This concept of optimum damping is very similar to power supply design in electronics, and damping alignments in boxed speaker design. If you over filter a power supply, or have too damped a speaker alignment, your system will sound lifeless. The opposite is also true - too little damping and the system will sound too "zingy".

As far as keeping a battery powered motor drive system charged and ready, a weekly charge is more than sufficient. Dmailer has a ritual which works for him, and if he went to a weekly charge regimen, he might end up like me and forget to charge his battery for a month at a time. I'm really quite bad about this - knowing how much capacity these batteries have, I push the limit to the point of forgetting. My customers have this figured out a whole lot better than I do (grin).

Cheers,
Thom @ Galibier

What would I get for a battery?  Would a lead acid house bank boat battery work?