Sorry about the lack of info here. I'm not sure what transducer I will end up using. I was figuring that with my rather limited knowledge of electronics, I'd probably have to find a transducer to fit whatever circuit I ended up with. Thanks for the link to the leach amp plans- very cool.
As for the infor requested. I need an amp that can be powered by an automotive electrical system, and accurately put out an ultrasonic frequency up to 50khz (adjustable) with an output of roughly 1300 watts rms coming out of the transducer (that is, taking into account the efficiency and such of whatever transducer is used). And preferably at 1.2-1.6V.
It seems that the possibility of modding a audio amp may very well be dependant on the design of the amp itself, making the answer different from one model to the next. I figured this would be the case.
One thing I was wondering was the possibility of sending a single signal tone through an unmodified amp, and then using a 555 circuit or such to open and close the circuit to the transducer at the desired frequency- effectively giving me the high powered ultrasonic square wave i am looking for. Of course, the 555 circuit would have to be able to handle the high power load, and I'm not wondering if doing such would damage the amplifier.
Thanks again!