Re: Stereo Automation?

[greenpjs@xxxxxxxxxx]

On Thu, 28 Apr 2011 09:48:25 +0000 (UTC), David White
<whitedavidp@xxxxxxxxxxx> wrote:

>One of my buddies wants to build a remote control mechanism to turn the
>volume control on his stereo. He imagines some kind of motor or servo
>from an RC application that is somehow linked to a pulley which connects
>to the volume knob with a rubber band or the like. It obviously needs to
>move slow and steady yet it need not move a huge distance (if geared
>properly). He doesn't want to use a huge RC radio to control it though.
>He wants something much smaller. Any ideas? He knows that there are
>boxes that can be added to a stereo that are essentially remote control
>volume devices but he is an audiophile and wants to add nothing to his
>system that might dirty the sound.
Before remote controls and electronic volume controls were popular, I
once created my own remote volume control using by using a passive
photo cell connected as a variable resistor.  The volume changed as
the light shining on the photocell changed.  I put the photocells (one
for each channel) in a small sealed box along with a small dimmable
lamp and then used x-10 to remotely vary the brightness.  It worked
really well.  Your friend may or may not think the addition of the
photocell and a regular resister will dirty his sound, but I found
that it did not affect the sound quality at all and I am pretty picky.