I am not sure what you mean, usually what I have seen (as far as I know) is that yes the output can be more than 2 channels, but usually that is only to monitor the recording (for playback) but also that with other equipment you can have multiple inputs also but usually audio, while a midi connection in and out also is there.
http://www.rolandus.com/p.ducts/details/703/specs/http://www.sweetwater.com..5--USB_Audio_Interfaceshttp://www.sweetwater.com...lsiNDI5NDk2NzI3OSJdfX0Mackie ProFX12
http://www.sweetwater.com...iZ216bgCFaZaMgodCAMAZwOutputs - Main 2 x XLR, 2 x 1/4"
Outputs - Direct No Direct Outputs
Outputs - Other 2 x RCA (Tape)
http://www.sweetwater.com/c264--Analog_Mixershttp://www.sweetwater.com/shop/studio/mixers/http://www.sweetwater.com...kmount_MIDI_InterfacesThat is not the only on-line place, there are others but the pictures are nice and you can usually look at the back of the unit also.
http://www.rme-audio.de/en_index.php Take the RME UFX just as an example. You can have 30 inputs and 30 outputs I think (I do not own one). What you get is software for the computer where you can adjust the output level (not the input level that is automatic) to monitor what was recorded, but where you put 30 output connections usually is done by optical fiber cable (TOS I think it is called) plus/or the usually left and right analog output channels so you would need more equipment for however many channels you would need.
That will cost more, a lot more perhaps.
Just having one unit, I really do not know, I guess you would have to view each list of different items (mixers, audio/interfaces, whatever) and see what you think you need.
Because like I said, I am not sure what you mean. All channels of the recording would go through the USB2.0 connection though because like RME stated, USB2.0 can handle about up to 100 channels before it can not handle anymore channels. I guess that is when you get into MADI then type equipment and can handle say like up to 192 channels in and 192 channels out, plus the SPDIF connection (2 channels) and whatever other output usually meaning like 396 or so channels altogether.
But usually that is audio, not midi, as midi is usually only one connection in and out (MIDI In and MIDI out) unless you go to a all MIDI device which I think I linked up above also. One can look around though, at anything there and read all about it also.
Oh, sometimes there may be a typing error on some of those pages, but usually not.
Just look at the categories under SHOP menu item up on top I think and you can view or look at all kinds of equipment.
http://www.sweetwater.com/ ??????
In other words, I doubt that you are going to find just one unit that does it all, perhaps there is, but right now, I am thinking you would need an interface, to a mixer, to output probably just left and right channels into monitors (speakers to hear it with). (which is usually mixed in Sonar back out to the audio/interface and you listen in stereo to the entire output (not needing adjustment after that).
But the recording is where in the DAW (digital audio workstation - home computer - Sonar program) you change the level volume of the different tracks to output it all together (when balanced and mixed) even out to a wave file or *.mp3 file to listen to with (if nothing else) your computer speakers - but left and right channels only.
You can get surround and make 5.1, 7.1 whatever surround channels recordings also and output those also with some of the equipment.
If getting a USB2.0 device (firewire is probably a headache nowadays with Windows Computers - no port for firewire usually), then make sure the drivers are really good and will support all OS systems perhaps in the future - well like Windows Vista, Windows 7, Windows 8, 8.1 and they work good). RME works really good for drivers, but usually that is for audio like other USB devices, sure Midi goes through that also.
I know this is a really lenghty post, but I am confused with what you want. An audio/interface (say like my RME Babyface) can record midi (has midi connections in and out) and also audio via USB2.0 to the computer and back out, and all of it goes in and out of the copmuter via USB2. but the audio/interface has midi connections and audio outputs and audio inputs on the unit. Need no mixer, that is done either in Sonar, or with the monitor program - TotalMixFX program in the computer - for only monitoring the output. The input in all cases is automatic, so the levels you send the recording into the audio/interface, must be adjusted so it is neither too loud nor too soft into the computer and Sonar. And with the automatic inputs, it has way more headroom than any analog equipment back 15 years ago, when Midi connections use to be on soundcards, and more leeway for the recording, but there are also digital mixers also and probably still analog equipment also. Depends on how much you want to spend on equipment.
You can buy audio/interfaces that also have gain controls on them for input (volume say) but I don't think any of those work with midi, only audio in and out of the interface.
post edited by spacealf - 2013/08/06 15:40:28