6 channel car amp (work in progress)

[djQUAN]

here's what I have completed so far....

three 2-channel preamp boards with gain control, one logic delayed muting circuit and +/-5V supply, and the amp1 and amp9B boards.



all I have left to do is the switching powersupply and case.

[V-bro]

Hey nice preamps! What are they?

------X-max. can be several meters on any driver, too bad it can be done only once...------

[djQUAN]

they are there for four things.

*limit bandwidth so they don't oscillate/pick up noise in the automotive environment.
*control gain so they can accept a wide range of sources.
*amplification so the T-amps can accept weak input signals.
*invert the signal so the output of the T-amps are in phase with the other amps in the system.

simply uses a MC33274 quad op amp. I had it for quite a while but never managed to put it to use so now is the time. [:P] the more common TL072/NE5532's don't seem to be quite happy with a low supply voltage so hopefully this one would work.

[V-bro]

Can you post the schematic? []

------X-max. can be several meters on any driver, too bad it can be done only once...------

[djQUAN]

I could but it still isn't tested so the component values might need adjusting. also, it's in my laptop and it doesn't want to work in the internet connection here. will try to post it when the laptop isn't acting up.

[djQUAN]

here are the schematics...

[Havoc]

looks very good djquan

[V-bro]

Thanks man! So did you test them? Are they good?

------X-max. can be several meters on any driver, too bad it can be done only once...------

[djQUAN]

I made a little plug with LED's for amp9 and while trying to power it up, I accidentally shorted the wake pins to the mute pins.

now, my amp9B draws 1.2amps at 11V input (no signal and no speakers) and the tripath chip gets really hot. dang....need to buy a new chip. now this project is pushed aside again.

[djQUAN]

I was thinking..... what if instead of using the amp9 plus amp1, I'll graft the amp1 to my amp2 car amp. would be nice to have a four channel staggered power output.