I have been looking for help Fixing iMic Hum. I sold my old G3/4 so I no longer own any modern Mac hardware with an line in (I do have an old iMac G3 but I haven’t tried using it for this — yet). And my old technique, using gramofile on my FreeBSD machine, no longer works: I rashly removed gramofile and it will no longer build due to some changes in the legacy system I am using. The SHM_LOCK issue didn’t crop up in older releases of FreeBSD 4.x.
shmbuf.c: In function `init_shm': shmbuf.c:157: `SHM_LOCK' undeclared (first use in this function) shmbuf.c:157: (Each undeclared identifier is reported only once shmbuf.c:157: for each function it appears in.) gmake[1]: *** [shmbuf.o] Error 1
So I am using the iMic II with Final Vinyl with limited success. I get a lot of hum (I assume ground loop hum) but when I drop the needle, it goes away, and I can then hear a much more faint buzzing sound that gets worse with more gain. I think the unshielded iMic is at fault.
I suppose I could try Audacity as well, to eliminate any software-related problems. As noted in the link above, this gets more complicated: I have never used the the Audio MIDI control panel before, not that it helped.
Any ideas on how to add some shielding will be welcomed.