This is a review and detailed measurements of the SMSL SU-6 stereo Bluetooth and USB DAC. It was sent to me by the company to be sold by Shenzhenaudio. It will cost US$169.99.
I really like the slick look of SU-6 with its white LED:
Yes, you can adjust the brightness level (I think there are four). The single touch button powers the unit and lets you cycle through inputs and settings. A remote control is provided to make that task easier. Back panel shows one of my favorite features: in-built power supply so no big dongle for that:
I think this is the smallest DAC with a built-in power supply.
SMSL SU-6 Measurements
As usual we start with our dashboard:
I expected superb performance and we have it, especially in one channel. Averaging the two still leaves a very respectable score as far as SINAD is concerned (sum of distortion and noise):
Dynamic range (how noisy the DAC is) is right up there as well:
Multitone shows superbly low distortion levels:
Linearity is as good as it gets:
Intermodulation distortion and noise is very low as well:
USB Jitter and noise shows some negligible (and utterly inaudible) unwanted tones:
Switching to Coax input I initially saw a lot of jitter. But then remembered the options for Digital PLL (DPPL) so played with the 8 different ones in there to find the optimal one:
Typical trade off here is slow lock time vs performance. By slow lock time I mean if you switch sample rates, there may be longer delay before the DAC starts to play. Hence the adjustability.
Lots of filters are provided for you to play with:
Filter selection naturally impacts measured performance in our wideband distortion+noise test:
Conclusions
Yes, we all get bored with one more desktop DAC with great performance. Here though, there is innovation in packaging and styling which works very well. The SU-6 definitely made me smile when I first powered it on in this regard.
I am happy to recommend the SMSL SU-6.