Very nice looking board. As with you plugging your bass into this direct to hear the pre's, are you using a 1\4" to xlr cord???
Or micing an amp?
Yah, what ARP said.
The M-500 boards are kind of neat that way. Each channel has 3 inputs, the mic input (we'll call this input 1), a line level tape return input (we'll call this input 2), and then a third input which is also line level except for channels 1~4 (we'll call this input 3).
There are some differences with the M-520 just because of 8 more channels...I'm going to focus on the M-512 here to avoid confusion.
Input 1 exists identically as far as function/features/routing across all channels 1~12, individual phantom switching, 30dB PAD and phase reverse per channel as well.
Input 2 is labeled TAPE on channels 1~8, and can be selected as the main input to the channel strip, and/or accessed as the source for the AUX 1-2 and/or AUX 3-4 busses for cue feeds when overdubbing, and ALSO can be independently sourced in the monitor mixer for the engineer (the monitor mixer is an 8 channel submixer on the M-512 and each channel can individually source either PGM busses 1~8 or TAPE returns 1~8). On channels 9~12 input 2 is labeled 2TR A L, 2TR A R, 2TR B L, 2TR B R respectively, which comprise two stereo halftrack tape machine returns. These can be sourced as the main input to the respective channel, and ALSO can be directly sourced by the engineer at any time in the MONITOR SELECT switchrack.
Input 3 is no less interesting...on channels 1~2 as previously mentioned they are Hi-Z guitar preamp inputs for passive instruments. Channels 3~4 comprise a stereo RIAA phono
preamp. Channels 5~8 they are simply labeled LINE and are source switcheable as the main input to those channels. On channels 9~12 they are still labeled as LINE and as with channels 5~8 are accessible as the main input to the channel strip, but ALSO can be independently sourced by the AUX 1-2 and AUX 3-4 busses.
LOTS of possibilities for routing and monitoring, and for plugging up a variety of sources.