Once everything was connected and Roon configured to use the MU1 as Core to Client, we turned up the Meishu's volume to check for noise. We were pleasantly surprised that even with our ears in the tweeter horn, there was zero hiss. That was a good start. The first music we played was Opium Moon by Opium Moon.
On this album the Los Angeles band weaves a sonic tapestry that mesmerizes and involves. Relaxed percussion, deep fretless bass, subtle violin and meandering dulcimer are the main ingredients. With the MU1 as D/D converter, the soundstage was wide, dynamics were old-fashioned large and higher-pitched instruments solidly carried aloft by deep warm bass. When we set the French DAC to oversampling, some air was lost for a subtle but noticeable change. With oversampling turned off, the sound bloomed again. This merits a remark. When using a NOS DAC, there is a chance that some high-frequency noise will leak into your amplifier to modulate its behavior with some distortion. In our case, the amp did not suffer anything. With the MU1⇒NOS DAC duo, the MU1 now acted as external oversampler. According to Eelco, this filters out any energy from 22kHz-154kHz. The analog filter in the NOS DAC would attenuate it as well. But when a DAC runs its own upsampler as the vast majority does but still allows you to defeat it, comparing it to the MU1's own filter can painfully reveal the resolution losses of generic on-chip upsamplers.
Next came a Bandcamp download, The Famous Unknowns of Lindsay Buckland and Carlos Vamos. These are busking street musicians who use lots of loops to create a captivating atmosphere. The longer a passer-by stops, the more he might be inclined to pay the musicians. Also, a song composed in this fashion may meander. This recording was a perfect continuation of Opium Moon. Australian Linsday Buckland designed and constructed his very own stringed instrument. An electric dulcimer is the best description for it.
Via Midi circuitry, he coaxes from his e-dulcimer a wealth of possible sounds which, recorded and looped, combine into a broad pallet of simultaneous instruments. Just like the MU1, playing loops needs perfect timing. The musician must tap the right foot pedal at exactly the right time. The other artist here is guitarist Carlos Vamos. One of his trademarks is a tapping technique he picked up after attending a Stanley Jordan concert. It uses both hands to tap the strings like a set of hammers. Though the recording is RedBook standard and dynamic range limited, it is great fun.
Also from Bandcamp came 2013's Doralice by Doralice. This is guitar, banjo, violin, accordion and why not, a child's piano to be quite eclectic. Doralice prove that producing your own album and using Bandcamp to cut out a record company is fruitful musically and sonically. We liked how the MU1 opened up this recording and put the instruments in a virtual soundstage all in a very credible way. Throughout the listening period we switched between TotalDAC and T+A DAC 8 and each time found the TotalDAC in non-oversampling mode to be the preferred partner. We can't wait for the MU2 upgrade which will add DAC functionality. As far as we know, current FPGA-based DACs either convert everything to DSD like Nagra and PS Audio; or to PCM like Chord. What Grimm will do remains to be seen.
Grimm's special sauce of custom FPGA for all up/down/resampling.