Never misunderestimate the ability of the forum to overthink even the simplest things. Full disclosure: I converted AC to DC battery, did none of that, and it was audibly quite a bit better. Just not that hard. Unless you make it so.
Possibly Dumb Question re:Battery as a power supply
I have bought a new Clearaudio Performance DC Wood turntable. I plan to drive to the dealer in Atlanta and pick it up next Wednesday. I have seen the wall wart power supply which comes with the TT, and it is not a pretty sight. Clearaudio sells an upgraded 12V battery and charger supply for "only" $1,200.00. I don't wish to present myself as a parsimonious individual, but $1,200.00 seems a bit steep to me. I am wondering what problems would ensue if I bought a moderately sized (say 25 or 30 lbs.) , sealed, lead acid, 12V rechargeable battery; attached the proper wires to connect to the TT, and used it as a power supply. When the battery runs down I could just take it to my workshop and use my electronic, automatic battery charger I use to recharge car, truck and tractor batteries to bring it back to full power. As little current as the TT uses this shouldn't be too frequent a chore. It is just a possibility, but if it is feasible I might try it. I would really appreciate any and all comments, criticism or warnings.
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- 52 posts total
@lewm , just so. An MC7812 requires 19VDC if I remember correctly. And it's hard to know the characteristics of any internal regulation or the motor, and it may not even be obvious about how motor speed relates to platter speed. Doable, sure. How much of a project? Depends on your luck and how much test equipment you have lying around. If you don't have any test equipment, it'll take some pretty dumb luck not to void the warrantee. Only way around it I can see is to measure (or otherwise determine) the voltage on the manufacturer's battery pack. Then replicate with a comparable rechargeable pack of your own. And don't forget to protect the pack with a diode and protect the motor with a fuse! |
Drop out due to VR is usually dependent upon many factors including current draw most importantly. I built a PS for my Klyne 6LX which has regulators on board the audio chassis. The PS needed to put out not more than 4-6V above the needed regulated V. I am sure an 18V battery or a 24V one at most would work for the clearaudio. We don’t have enough info even to guess. |
I should have mentioned another issue: variability in parts. For example, the MC7812 is specced to regulate +/- 4% or so; which means that if you buy 5 of them, one should be within 1%. That’s 33 RPM to 33.6 RPM. Assuming you need it. Maybe you don't. Like I said, it’s a project. You might have the time and inclination for it, or you just might want to listen to music. |
The OEM
wall wart
is a 12V 600mA regulated
switching
power supply, so long as a battery can supply a regulated 12V
with min. 600mA it should be find. Since the Performance DC
feathered fine speed adjustment on the back of the turntable to compensate variability
in voltage difference, I think using a 7812 regulator shouldn't cause any problem. https://hifiheaven.net/shop/image/cache/catalog/Clearaudio/12V1-750x750.JPG |
- 52 posts total