Originally Posted by pandy71
...if you really wish to have HQ audio then all those problems need to be addressed properly, audio supply and ground need to be clean, proper PCB layout etc.
It's passably OK for the intended job, but it could have been so
much better at the minor expense of dedicated audio stage voltage regulation and correct signal ground referencing. Also, setting up a guard band around the audio stages would have been very easy and quite effective at keeping radiated digital noise away from the audio signals. All of this was standard practice at the time on high quality audio equipment.
Show the schematics and PCB layout to any competent electronics design engineer and they'll tell you exactly the same thing. I suspect that penny-pinching is partly responsible as doing it properly can be very cheap, but not quite free.
I'm happy to accept it for what it is as I don't use the Amiga for any serious audio work, but I certainly wouldn't attempt doing so without at least a partial circuit redesign.
I re-capped my 2B A1200 at the weekend, so I know they're not responsible in my case. The incoming supply rails are as clean as can be expected from the fairly crude (by modern standards) external PSU design, so I'm happy that nothing is broken per-se.
I am not
moaning. This is exactly what I'd expect to see from the hardware that's sitting in front of me. I'm under no illusions that high quality audio will be delivered or should be expected.