Measurements and conclusion
Contents
We measured the Volumio Motivo on a few aspects. We were curious about jitter, the power supply and, of course, generic performance.
Jitter we measured with the Wavecrest. Unfortunately, we couldn’t get a lock on the Aeroflex, so a deeper phase-noise measurement failed. It is a bit of a fussy and sometimes a bit capricious device. We measured the Volumio Primo as an indication, since we do get a lock on that crystal. That one has slightly higher jitter, so the phase noise of the Motivo will be slightly lower.
We also measured the – surprisingly fine – standard power supply in terms of noise and stability. That was done with the Rigol Electronic load and the Tekbox LISN with splitter for common mode and differential mode noise.
Finally, the generic measurements. Those were done with the trusty Prism dScope III.
Volumio Motivo – Jitter
Jitter is completely in line with expectations. We see around 8ps of jitter (1-Sigma). Adjacent Cycle jitter is around 14 ps. Not bad at all for a product in this class. Low frequency noise is quite low at 4.5as (crazy scale, we know. It can go to dB, but that’s not always convenient either).
When we connect the lab power supply to it, the jitter goes up….odd. We can conclude that the clock is still sensitive to the power supply. However, Volumio has clearly included a better power supply than with previous models. So perfect!
We see that the phase noise is around -42dBc at 1Hz and -75dBc at 10 Hz. Realize that this is a 100 MHz clock, so it is not a bad score for a device in this class. The jitter we see is pretty close to what we measure on the Wavecrest. So we are pretty confident that these numbers are correct.
Volumio Motivo – Power supply
The stability is good enough. The player draws about 1A when booted up. Then the power supply just delivers 9V nicely. At 4A we see 8.4V which is a bit on the low side, we think. All in all, the power supply drops 0.7V when looking at 0 and 4A load.
The power supply is also remarkably quiet for a (included) switching adapter. We see some spikes, of course, but it is not excessive. It is also mostly common mode, which is to be expected.
Could it be quieter? Yes… definitely. But know that in this case you have to spend quite a bit for it to be quieter AND bring audible improvements.
Volumio Motivo – noise floor
We cannot measure very much, since there are no analog or digital inputs we can use. However, we can see that there is a neat noise floor. Both without and with a signal active. -120dBFS is just very good. Without an input signal, the Volumio does have to mute the output, because -145 dBFS is not really realistic in this class. We know devices that are quieter, however, those cost at least triple. All in all, decent results.
Your review is thorough and technical, which I really appreciate. However, I have some reservations about the usefulness of measuring factors like jitter. The main issue is that it only reflects the performance of the specific unit you tested, without accounting for variability between different units of the same model. There’s always a risk that your test unit could be an outlier, either particularly good or bad, which might skew the overall conclusions of the review.