I have put the BluDave combo through a lot of heavy testing and listening over the last few days because I had a Blu in for trying out and have had to make a decision as to whether I wanted one or not. The one I have has to go back as it's the wrong colour, however I do want one and I have ordered one in silver, but it won't be a totally straightforward decision for everyone I think because one has to weigh up the gains against the price and there will be several variables involved in that assessment.
I've played files direct to Dave and via Blu, same with CD's using my CD transport and, finally, CD's direct from Blu and I've used all of the input types available on Dave. Contrary to some of the comments on here about CD being dead, I have actually really enjoyed digging out some of my old CD's and playing them and it's been a bit of a trip down memory lane. Each to their own.
I play PCM only, not DSD but anyway, here's what I've found the Blu adds to the Dave (warning, non technical appraisal):
Warmer and slightly darker tone
Smoother and more refined presentation
More transparent with instruments more clearly placed, separated and defined.
Clearer and deeper bass with greater separation of the bass as an instrument which can be clearly placed in its own space in the room
No smearing or blurring of notes and parts, everything is very clearly defined
Cymbals, tambourines etc are smoother with no harsh edges
Voices sound like people in the room with you
More relaxed presentation which is non-fatiguing. Can play louder as a consequence (not the same as the Blu being 2-3db lower in output)
Creates an authentic soundstage
More 3 dimensional
More lifelike - it's like being there with the musicians
More emotive and greater involvement with the music. Certain pieces have shocked me at the depth of feeling that is conveyed, female voices especially
Harder to have running as background music due to point above - keep getting distracted and drawn in, classical music in particular
Red book elevated to a different level and I'm questioning the need for buying hires files now
One point of interest that has arisen has been a welcome surprise. I'm a guitar player and like rock and blues and when I was a kid, I played a lot of rock and I generally used to prefer live albums to studio, there seemed to be more life and energy that was often lost in the studio. Anyway, as I progressed into a digital system and away from LP's, I started to veer away from the live albums as I didn't like them as much which I thought was just my taste changing over time. I haven't played live albums in years but, with the BluDave combo, I've been digging out some of those old CD's and they sound terrific. I was trying to rationalise that and I think that it is the fact that the presentation is so open, smoother and analogue like. Whatever, I am happy about it and have rediscovered some very old friends this weekend.
Having said all that, my wife still feels that the best sound comes from my CD transport direct into Dave - that was always the best sound that I got prior to Blu. Her reason was that it sounded 'more detailed'. It actually isn't, but I think that the slight hints of digital presentation without the Blu create an initial impression of detail due to the slightly sharper digital edges that still remain and which the Blu smooths away. I have done far more listening than her over the last few days and the BluDave has tremendous natural depth and detail. Nonetheless, it's not necessarily a no brainer decision and my wife wouldn't spend the money!
For me, I will be trading my CD transport which makes it an easier financial pill to swallow. If it were a standalone M Scaler at similar price, I'd have to think long and hard over the value vs gains delivered, although I think I'd still get one anyway! I think that the BluDave combo is something that you definitely need to audition, even if only to hear how good digital can sound. After so many years, I finally think that the original promise of digital has been realised. Sorry for the long post but hope it may be useful to someone like me who was wondering what to do.