I use the ES-9 outs to the inputs of a Motu M4 audio interface that is connected to my monitors. The ES-9 outs come from an iPad where I control all levels. The Motu isn't connected to the iPad (iOS can only do one audio interface at a time) -just straight in & out. So it's a pretty robust chain. If I want to, I connect the Motu to my mac for more fun.

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