The established UK hi-fi magazine HiFi News published a review of the MU2. Andrew Everard evaluated its sound and Paul Miller took it to his work bench for measurements. Both became highly impressed.
Andrew started listening to a few pop albums. “That ability to bring out the finest detail was also in evidence with Peter Gabriel’s ‘Sledgehammer’, from his So album. Big and bold this highly commercial track may be, but the MU2 delved deep into the percussion, laying down a solid foundation that powered the music along, while layering the multiple instrumental lines above it, making every strand easily audible.“
“With classical music, Grimm’s player is every bit as convincing (…) From the gentle dreamlike opening to the explosive power of the full orchestra, this choreographic symphony enjoyed a weight and impact – especially in the pounding percussion – to test any amplification connected downstream of the MU2.”.
And Andrew loved the rendering of Jazz too: “the beautifully measured Tord Gustavsen Trio album Seeing was here presented with enthralling levels of detail. Piano, bass and drums were wonderfully resolved, so the impression was of having the musicians before the listener. One can literally hang on every note, from Gustavsen’s piano through to the resonant, depth-plumbing bass and the gentle patter of the drums.”
Returning from his lab, Paul Miller reported that “The technical performance of the MU2 is state-of-the-art in respect of distortion and jitter suppression (<5psec with all sample rates / all inputs and with no observable phase noise – suppression of correlated jitter is almost total).”
In conclusion: “The Grimm Audio MU2 may at first seem something of an outlier: unusual looks, possibly an unfamiliar brand, and of course that reliance on Roon as an operating system. However, use it for a short while and everything falls into place, from the ease with which music can be accessed to the purity and drama with which it’s reproduced. Get all your subscriptions in place, sit back, and enjoy…”
HiFi News handed the MU2 an ‘Outstanding product’ badge with a rarely offered 90% score.

“It sounds fast and crisp then rich, vibrant and soulful” Andrew Everard, HiFi News, UK.