It is possible to use a celniod to keep power from the amp, and you can
set up a switch for the speakers to go from amp to head unit but why?
Just set up a system that will be designed for that kind of use.  Dual
battery system with a deep cycle battery.  That way you can jam out all
you want and if you leave it on when you fall asleep it wont hurt
anything.  Problem solved. This is what I did in my westy and it works
great. I have two amps and some video equipment and I only have run it
down to no power once, but it charged back up like it is supposed to.
It wasn't even that expensive.
Adrian

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of Simon Reinhardt
Sent: Saturday, November 09, 2002 10:24 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Stereo Power Amp

Larry,
It is possible to do it, but it would be weird and complex. As
suggested already, you could use both the line-level and speaker-level
outputs of the head unit; line while driving and speaker while parked.
It would be very easy to put a power switch on the "switched power"
lead that comes off the head unit and signals the amp to turn on. The
main gotcha is that you'd have to absolutely interrupt the
speaker-level outputs when the amp is on. Easy enough: on/off switches
for each wire, or a switch that has multiple circuits built in to
handle maybe up to four leads at once.
Do you really need every single speaker active when you're parked? If
you only used one pair, there would be fewer wires to switch on/off...
-Simon

On Saturday, November 9, 2002, at 09:14  AM, Larry Chase wrote:
>
> One of the goals I had in mind was to have a small external power amp.
>
> The idea was to use the external amp while driving and to turn it off
> and just use the head unit's internal amp when camping.
>
> The reason being to minimize power consumption when camping.