I recently picked up an oracle turntable which requires a 27vdc power supply. Originally, it was just a wallwart, but Oracle doesn't sell them any more, and their dealers have no stock. Which leaves me to designing my own. I would assume some regulation would be advised, but a DC motor in a turntable, but I don't know if the onboard circuity handles that or not.

Can anyone point me to some plans to create a regulated DC power supply. I joked with squidward saying I was going to make a tube power supply, but realize it's probably not the best option at this voltage.

You can do one of two things. First, do a search of the web for DC power supplies or, go to the library and find something appropriate for your turntable. 27 volts dc is an odd value, for the components that are currently available for regulators, but no big deal. Depending on what your size limitations are, you may have to do something external, you can use a transformer, more current, and then regulate and step down the voltage. Since you have the original board, what is stopping you from replacing the components that are there to restore this item to its original working order? My next question, is, why did the power supply die? Maybe the motor was at issue to begin with. Find the voltage on the motor and then check the current with a battery or another dc source just to check.

i bought the TT from someone who inherited the turntable, I expect that it was working properly and the wallwart was misplaced. The on board circuitry is the DC motor controller, but what I haven't been able to determine is if there is some sort of regulation built into that area or if it was part of the wall wart. I'll just continue to search on and hopefully oracle can provide some better info in their next response.

Thanks.

Seems like a by-the-book LM317 circuit would be adequate to get you going. Something like a standard 24VAC transformer with a full-wave bridge, followed by filter and bypass caps, and then a standard LM317 regulator circuit with protection diodes, as shown in figure 3 (at least on mine :D) of the datasheet. Do you happen to know how much current the supply is supposed to provide? I'm guessing not all that much. Even so, you'd probably want to put the LM317 on a heatsink, and the current requirements would set the heatsink size.

current demand is only 350 mA. i'll do some reading on the LM317. thank you!

Good, that's certainly low current. The LM317, in the circuit described above, will just need a small heat sink, something like digi-key part #HS225-ND for example, or anything along those lines.

I recently picked up an oracle turntable which requires a 27vdc power supply. Originally, it was just a wallwart, but Oracle doesn't sell them any more, and their dealers have no stock. Which leaves me to designing my own. I would assume some regulation would be advised, but a DC motor in a turntable, but I don't know if the onboard circuity handles that or not.

Can anyone point me to some plans to create a regulated DC power supply. I joked with squidward saying I was going to make a tube power supply, but realize it's probably not the best option at this voltage.
If you can live with 28vDC, maybe this (http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&pa=1707075&productId=1707075) one or this (http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&pa=1707091&productId=1707091) one will do. I found them in my Jameco catalog. I wouldn't think 1vDC should make a big difference.