Welcome here! and congratulations on getting your Model II.
Hi, i'm the proud owner of a model II and about to buy a tonematch to get the most out of this magnificent beast. Most of the time i will be needing the phantom power just on channel one but i know that phantom power applies to channel 1-3.
It is not yet clear to me if i can safely plug in a guitar, keyboard or mp3 player on channel 2 and/or 3 when phantom power is turned on? Any help would be appreciated! Thanks in advance!
Yes, you can safely plug in a guitar, keyboard or mp3 player into channels 1, 2, or 3 when you have the Phantom Power turned on.
Here's a little background: The Phantom Power is only applied to the XLR connection in the channels 1, 2, 3 combo jacks. All the devices you mentioned would typically be connected using the 1/4" jack. Any properly wired XLR connection to a device or microphone that does not require Phantom Power will not be harmed if you have the Phantom Power turned on.
Does that help?