Here is sort of an answer that I got from tascam:
2010-12-17 19:57:45
Hello louie,
Thank you for contacting TASCAM.
Our customer support representative, NFaison, has written
the following response to your message:
Louie,
We don't have that exact information.
However, the specification for power consumption with phantom power being used is 9 watts.
Thank you for your interest in TASCAM products.
Below is a copy of the message that you submitted:
Support Reference Code: EL4JUEFX
Support Request Type: Pre-Sales Information
Product: DR-680
Your Question:
when in record mode, how much power do each pair of channels consume when phantom 48V is on and how much when they are off. Also, if you are only using channels 1-4 do channels 5-8 consume power? thanks for your help in advance.