Admit to having been dragged kicking into bench testing the H4 (a very cheap SD flash deck out for nearly 2 years), but here is the technical low down on many issues plaguing H4 users having problems with input distortion and noise.
Sort of a non-review compared to MT and R-09 reviews I've done, but seems there's now enough tech disclosure to know what you might be able to do, how to adjust the settings, and maybe what's not so H4 practical.
Go to:
www.sonicstudios.com/zoomh4rv.htm