Quote Originally Posted by N8YX View Post
The switch board has a 5V reference applied to a couple of its traces and the Speech switch must be isolated from these, as the ADSP2 unit requires a momentary ground on each of its control lines to properly select the various modes and bandwidths. The IC-EX310 Audio Input line is just that...an "input" to the audio preamp. The main-board audio signal chain must be broken in order to insert the I/O leads. Additionally, the volume-control pot on the front panel merely varies the gain of the AF preamp IC and cannot be used as an injection point.
Yes - working solutions are quite different to initial ideas, its amazing how many unanticipated hurdles are come across when developing a mod, program or solution to a problem!

I have yet to expeience any good DSP processing. I have probably been exposed to old generation AF dsp only, so it sounds like the later generation dsp is quite good. Must be good for you to consider putting it into your receivers. :)