snd_hda VIA VT1708S record problem

I have Asus M5A78L-M/USB3 motherboard with integrated VIA VT1708S sound chip/ codec. After some manual nid-pinning in device.hints I have sound (not before). Mostly I use stereo Rear output and Front Headphones. So, I disabled all other nids except two stereo outputs (Rear and Front) and two microphone inputs (Rear and Front).
My problem is: I have terrible noise trying to record from microphone. But everything if O.K. in Windows for the same motherboard. May be some known tricks? Or anything to try?
Can you set it to "line" instead of "microphone"? The reason is that microphone inputs usually have extra amplification, which might be causing clipping.
Should I reboot? If not, than it doesn't help.
And yes, I disabled "igain" and "ogain" in mixer. Noise have large relative amplitude and well-pronounced main harmonic at 8kHz. More than that, when I plug in the microphone (dynamic one, of course) I hear rather strong hiss out of it! Some output is going to microphone???
No help with rebooting or line option. So pity, I can't record via this onboard VIA1708S (or PCI AudioPhile2496)...