I wouldn't say that the M scaler is needed, but it does a function that the DAC does not. You need a good streamer and internet source to appreciat the M-scaler. Garbage in, garbage out. When I first got the M-scaler, it degraded the sound rather than improving it. When you are dropping bits and losing detail, upscaling to higher resolution just makes it easier to hear. Now with the hard wired internet, audiophile switch, and Innuos streamer, it definitely gives DAVE better raw materials to work with.
thanks for your comment.
Jerry