12 volt bipolar power supply - how do I go about making one?

[mthibeau]

A friend of mine gave me a BBE sonic maximizer OEM board (from 1989) - never used, never even opened.

It's a PCB all built and populated, with stereo RCA ins/outs, board mounted pots, etc.

The documentation for the OEM board says to use a 12v DC bipolar power supply.

How would I go about building one, or modifying an existing power supply to do bipolar. Having trouble finding something already built I could just buy (like a wall wart supply that just does bipolar).


- MikeT

[anchovie]

http://www.generalguitargadgets.com/projects/24-power-supplies/137-bipolar-power-supply

[tasos]

http://tonepad.com/project.asp?id=64
You could just plug your 9v ac adaptor into this...

[mthibeau]

Thanks all, will try the GGG one.

- Mike

[mthibeau]

OK, I am finally ready to build the GGG bi-polar supply, but I am not sure what secondary supply I should buy.

I need 12v bi-polar power for the project.

Would this 15v AC supply work as the secondary?
http://www.ebay.com/itm/VISION-15-VOLT-AC-POWER-ADAPTER-SUPPLY-D48-15-1000D-/120953544109?pt=LH_DefaultDomain_0&hash=item1c29649dad

If not, could someone suggest one (Ebay, Amazon, whatever...)

- Thanks in advance...

[R.G.]

 Whatever you do, I suggest you read "Power Supplies Basics" at http://www.geofex.com.

[Jdansti]

I've built the GGG one for a noise gate and it works great. I picked up a $5 20VAC wall wart at a local electronics surplus store.  While I'm not afraid of building an entire PS from scratch, I prefer to use a plug-in transformer that drops the AC voltage so I'm only dealing with no more than 25VAC.

Here's an inexpensive example:  http://www.alltronics.com/cgi-bin/category.cgi?item=96E012

One bit of advice: label the end of the AC adapter showing the voltage. If possible, use a different size jack and plug so you can't accidentally plug it into one of your 9VDC pedals.

Edit: The D48-15-1000D model you found appears to have an output current of 1A and would probably work as long as the current requirement of your pedal is <1A.  It is probably unregulated, which means that its output voltage will be something above 15V as long as you stay below 1A current draw. The regulators on the GGG PS require the input voltage to be a couple of volts greater than the regulated output voltage, so you're probably fine with this model.  I'd take R.G.'s advice and read up on power supplies before jumping in, though.