I have No. 00015. I did have the same problem ("Mr Squeaky Mouse & Friends), which is exacerbated by various factors:

- using the line outs (Home mode) on the unit with headphones with low impedance
- earth loops, or improper grounding of the unit in the car install
- amp gain set too high on low impedance amps.

I sorted out the squeaky noise in the car by using good quality grounding wire, careful gain setting at the amp, and a good quality amp.

In the end, it is not really possible to completely remove all the noise, since it's a design issue. There is little you can do about this. However, I did improve it a lot as a consequence of having to repair the internal audio harness of the box following a shield wire breakage. In re-soldering the wiring, I also re-arranged the routing of the cables to reduce stress due to bad routing. Once this was done I was surprised to find that the squeaky noises had all but disappeared. Hoowever, this solution would require soldering and the ability to do careful cable re-routing, so this may not be for you. I would be glad to help if you are in the UK or the Netherlands, so please mail me off line.

I am sad that he thinks it's intrusive enough to not use it - I have a friend here who borrows my unit to store keyboard backings for stage performances (he took the photos at the owner's meets) and just plugs it into an input channel to the group's mixer via an isolator transformer.