Can this circuit be modded to work with lower power input si

[Kasterborus]

I built this kit last night, and tapped the input across one of my
speakers.

http://www.velleman.be/images/tmp/MK114.jpg

It's their standard one channel light organ designed to work with low
voltage lamps.

It worked, but I had to crank the speaker really high to get the lamp
to flash. Looking at the circuit it seems that all I need to do is
find a way to flash one side of the optisolator to make it work. At
the moment it's using the power from the audio amplifier to do this,
but could I add a transistor from the 12v supply, connect this to the
OI input and feed in a lower power signal to do the switching?

Ideally I would like to run this from an audio line level signal, not
the speaker output of my amp.

Any input is always appreciated.

Dave

 

[Kasterborus]

I was looking at the schematic again - do you think that the pin 6 on
the OI could be wired up to do the job?
It seems to provide an electrical input to trigger the switching .

Maybe breaking the connections on pin 1 , connecting this to pin 6.
Then breaking pin 2 and connecting this to GND.

Obviously at this point I would never want to wire it up to a speaker
again, but maybe the half rectified line level signal would be enough.

I'm great with theory, just no so good with number crunching.

 

[Kasterborus]

Is there some safety reason why you need to use the opto?- Hide quoted text -

No I don't reallly need the opto - the line level signal is 'safe' -
that's why I was thinking about using the transistor in the OI - if I
understand the pin out, then pin 6 is an electrical 'base'.

Dave