Re: Using Op-Amp to drive Amp Gauge with Audio Signal

Tom wrote:

Just to let you know it worked great!

Excellent. Now we can move on to making the scale read in decibels. ;-)

I do have one concern that I
was wondering if I could get some advice on. I set up everything as
mentioned above. To get the +/-12V for the op-amp, I took my 24V
supply and split it with two resistors. The tap in the middle being
ground. I had to use that as ground for the audio ground and the final
output resistor. My concern is what problems could be encountered
having the audio ground hooked to this "floating ground" and at the
same time having the ground go to the main amp? Is there a way to
have the V- be ground without having to DC offset? Possibly the
bridge before the op-amp?

The only risk I can think of is if turning the volume way up bounces the 24 volt supply around, feeding another, unintended signal into the circuit. But if the 24 volt supply is stiff or regulated, that is not a problem. The opamp has to be able to swing both ways to work with the AC signal. So the simulated split supply is probably fine.

Tom




--
Regards,

John Popelish
.