Wanted to see if anyone has used both the A9 or M1 for neck pain and which they feel works best. I am trying to decide which to try for my cervical pain due to stenosis.
I recommend you read Dr. Bob’s post here:
The A9 essentially runs one protocol (Omni 8) and supports 9V lithium batteries which can last for many hours. The M1 supports multiple protocols (like Alpha and Schumann4 as he references in addition to having the Omni 8 protocol) and has a small camcorder battery which requires changing every couple of hours.
I hope this helps.