Re: [Harp-L] Kinder AFB+ Questions

[fjm <bad_hat@xxxxxxxx>]

Joe abcdeasy had a good answer to Ken's question.  This post is 
originally from July of 2008. I'll just quote it in its entirety, fjm


I have a friend who wants to convert AFB to external power.  I'm
looking into building a solution for him.  In speaking with Kinder
that unit only draws a few milliamps. That's a very low current
demand.   However it uses a bipolar power supply that is plus and
minus 9VDC.  That's why there are two 9V batteries.  The two 9VDC wall
wart approach works fine and is cheap and easy however its not a very
elegant solution.  Who wants two more wall warts to carry around and
take up more outlet space?

The better way to approach it is to build an external bipolar power
pack that uses one AC connection similar to a laptop power pack.  I'm
sure Kinder could have built an external supply but my guess is he
probably couldn't do it very cost effectively.  He also probably
figured that not too many people would want or need external power
since the unit can run for a very long time on a set of batteries.

Here is a complete bipolar supply solution that uses one 12VAC wall
wart.  All you need to do is populate the circuit board, put it in a
project box and wire it to the AFB using a three pin connector.
http://www.musicfromouterspace.com/analogsynth/WALLWARTSUPPLY/WALLWARTSUPPLY.php
Maybe $40 total for the entire project?

I'll build something similar to the above but without a wall wart.  It
will use a small transformer inside of the project box.

Anyway, its not a very big deal to build an external supply or use two
wall warts.

I also agree that the inside of the AFB is a real mess !  Not very mod
friendly and very tight on space.

Joe