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Vintage Synth Repair

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RE: [vintagesynthrepair] Re:Power supply for Roland M240

2008-12-22 by francois

Hi Scott,

thanks for your advice. You're right: modifying a PC supply could be a long and painful process, far above my available time.
Actually, some better googling revealed abundance of adjustable symmetric PSU schematics, mostly based on LM317/337. Sounds to be a better option if I don't find a genuine ACC120 at reasonable price.

François



To: vintagesynthrepair@yahoogroups.com
From: painintheamp@...
Date: Tue, 23 Dec 2008 02:06:51 +0800
Subject: [vintagesynthrepair] Re:Power supply for Roland M240



Hi...
I wouldnt mess with a modified PC supply.

1st...try some surplus electronics places online.

You can get a little leeway on the volts out (if Roland wants 21.5 , you can supply up to 24vdc most likely as long as the supply can do the +/- 500mA.)

A used one is possible too

The transformer inside will have 24VAC with CenterTap then a full wave rectifier, an LM317 and LM337 adjustable +/-regulators inside. Each set up for the 21.5 Of course they'll be a couple of resistors and filter caps too.(Thats how I'd design one.)

Scott Frye
AudioFixation
Consumer / Pro Audio Repair
Southern VT

"Resistance is futile but.....
Impedance is much more complex"

Scott Frye
AudioFixation
Consumer / Pro Audio Repair
Southern VT

"Resistance is futile but.....
Impedance is much more complex"




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