Glad to hear you like it, so do we! We had the same idea and made balanced input/output pairs with Neutrik jacks.
- they have ground in the middle, so the 3-pin is [1, gnd, 3] and 5-pin [1, 2, gnd, 3, 4], if that makes sense. So the 3-pin has two channels, 5-pin has four channels.
- JST PH
- So on the Mix 01 you have the inputs, normalled inputs, outputs and normalled outputs on 4 connectors. The 'normalled' ins/outs can be thought of as the default connections, if nothing is in the jack. So if you want to add balanced stereo outs, you'd use the regular output 3-pin connector. If you want the balanced outs to disconnect if you put something in the output jack on the mixer, then you'd use the normalled output connector. Makes sense?
Same for the inputs, of which obviously there are four.
In terms of 'new connections', the short answer so far might be zero, since you're not accessing any channels beyond those available on the front panel.
But there's an additional stereo bus input connector, which lets you add two inputs, or the summed outputs from another mixer, directly to the mixer bus. This gives you in a sense unlimited expansion possibility.
- If you want balanced ins/outs then you need balanced line drivers / receivers such as the THAT 1606 / 1646.
Sorry if this is a bit long and confusing, in reality it's really quite straightfoward! Perhaps the schematics will explain it better.
The easiest thing to do is to add balanced stereo outputs, for this you just connect a line driver to the output connector. Then you could add two or four balanced inputs, normalled to the mixer channels, meaning that if you plug something into e.g. channel 1 on the front panel then it disconnects the balanced input. If you want to go more advanced and add inputs straight to the bus, then you need to work out how you control the level of each input and how it is mixed on the stereo bus.
I should finish up the balanced input/output boards we made and make them available to DIYers. Happy to post the details if you prefer to build it yourself.