Hi there,
I'm completely new to audio recording and just bought a new DR-680 as my first recorder. I'd appreciate if someone could share a bit of their experience. With no mic connected, all settings reset to factory default (except recording mode changed to mono), and with the headphone volume max'ed, I tried to check the self noise of the recorder using a pair of headphones from Sennheiser (25-1 II). Here's what I found:
1) turning on/off phantom power generates 2 loud sounds in the recording each time I move the switch.
2) as long as I don't switch input to mic and set mic gain to high at the same time, I only need to set headphone volume to 9 or lower to eliminate most of the hissing from my headphones. But once setting input = mic & gain = high, the hissing jumps up. I need to set volume to 8 or lower to make my headphones quiet again. And for channel 1 (and only this channel), I will also hear a persistent radio interference sound (like the sound one can hear from a florescent light tube). For this channel, I have to set volume to 7 or lower to make my headphones quiet.
Are these normal? Is channel 1's extra noise something to be concerned about? On my computer I can see even if I ignore the operation noises, the recording file is not a flat line and by the spectral display, noise exists all the time.
Thanks,
Henry