Please don't take offense at this put the problem probably isn't the recorder.

Can you find what is causing the distortion and make sure that the input wasn't overloaded when you were recording it in the first place ?

Compression shouldn't alter the EQ that much and people usually use it to make a mix more cohesive. Have you tried using a limiter? If you have recorded your loudest track with out it clipping you can add a limiter to it to stop it clipping when you turn up the master in the mix.

Incidentally you can turn a compressor into a limiter by setting the compression ratio to infinity.

You can also try normalizing after compressing however this is a less attractive option as it will also boost noise.