DAVE w/ or w/out M Scaler?

The M-Scaler gives you more.  More detail.  More air.  Better separation.  A little smoother of sound but like ricred1 said, it is not absolutely certain this will make the sound better to your ears.  Most customers have been quite happy to add an m-scaler to their Dave.  I have yet to have a return.  

The general rule is...the better and more refined the DAC, the more an M-scaler does to change the sound.  And this goes for non-Chord DACs.  It was designed for the "TableTop" series from Chord so it is naturally intended to max out sound quality from a TT2 but arguably does even more for a Dave.  Most Dave customers follow up and get an M-Scaler.    

We have a 30 day return policy.  Your obligation is return shipping to NJ.  

@jjss49  this is an interesting question.    On the surface, you are right.  The approach with a NOS DAC is the exact opposite of what Chord is trying to do with the M-Scaler.  NOS DACs are trying to serve up a digital signal in its purest form while Chord and the M-Scaler are trying to recreate an analog signal as completely as possible driving the need for up-scaling.  Theory says you shouldn’t be able to hear a difference yet people do.   

In this thread poster ecwl talks a bit about this.  
https://audiophilestyle.com/forums/topic/46501-chords-new-m-scaler/

So theoretically, it should have no impact.  However, many M-Scaler users report improved sound even in pass through mode compared to USB.  
Check out this thread focused on the Denafrips Terminator over at Audiobacon.  
https://audiobacon.net/2019/02/28/denafrips-terminator-review/amp/

Ultimately, I don’t have an R2R DAC lying around that I can test this with.  You can be  certain it won’t take full advantage of what the M-Scaler is capable of.