In a move that solidifies its position at the pinnacle of digital audio reproduction, Dutch high-end specialist Grimm Audio has released a comprehensive firmware overhaul for its acclaimed MU1 and MU2 music streamers. Dubbed a “true milestone” by the company, the update—internally designated as v2 for the MU1 and v1 for the MU2—represents 18 months of intensive development and realizes the engineers’ original vision for these flagship devices.
For the first time, owners of the MU1 and MU2 can now integrate the streamers with a broader ecosystem of network sources beyond Roon. The update introduces full UPnP support, enabling seamless compatibility with popular music apps such as JPlay and BubbleUPnP. Users should note that a dedicated UPnP server must be present on the network, as the Grimm devices themselves do not provide this functionality. Additionally, Tidal Connect has been added, further expanding streaming options for discerning audiophiles.
Grimm Audio remains steadfast in its endorsement of Roon as the premier music management platform. The firmware elevates this partnership by certifying the MU1 and MU2 as official Roon Ready Endpoints. This certification grants the streamers their own distinct identity within the Roon interface, complete with a bespoke MU icon, a precise decibel-scaled volume control, and an innovative signal path viewer accessible via a simple blue button click. For those managing vast music libraries, the update ensures flawless integration with external Roon Servers, streamlining performance in even the most demanding setups.
Two standout features promise to redefine user convenience without compromising Grimm’s uncompromising sonic standards. Loudness Normalization, now available via UPnP and Tidal Connect, automatically adjusts playback levels to ensure albums from any genre maintain consistent perceived volume—no more reaching for the remote mid-session. Implemented as a transparent offset to the streamers’ exemplary built-in volume control, this function preserves absolute audio fidelity.
Equally intriguing is the new bit test function, designed for the meticulous audiophile. By streaming a specially crafted Grimm Audio test album—featuring tracks at varying sample rates and bit depths—users can verify the integrity of their entire digital chain, from Roon or UPnP sources through to the output. This tool empowers owners to confirm bit-perfect transmission with ease.
Beneath the surface, the update migrates the system to a newer Linux OS version, squashes rare bugs, and incorporates numerous under-the-hood refinements. The result is a more intuitive, robust, and future-proof platform that honors the MU1 and MU2’s reputation for reference-grade performance.
Grimm Audio invites users to explore the enhanced capabilities through updated software manuals, Quick Start guides, and detailed change logs, all available on the downloads tab of the MU1 and MU2 product pages on their website.
This firmware release not only broadens accessibility but reaffirms Grimm Audio’s commitment to innovation in the high-end streaming domain. For audiophiles seeking the ultimate in digital purity and versatility, the MU1 and MU2 have never been more compelling.













