- Internal DAC chip: AKM4420
Setup: i7 computer system - same as Essence One. Analogue output from Touch going into the E-MU 0404USB for measurements.
Oscilloscope measurement of 1kHz square wave, 0dBFS off the analogue RCA output:
Mostly better results all around compared to the SB3. Frequency response within tighter range over the 20-20kHz spectrum, noise levels 1 dB lower in the 16-bit domain (as if it could go any lower!?), and about -4dB lower with 24-bit data giving the Touch DAC about 17.5 bits of dynamic range. Interestingly, the stereo crosstalk is a bit higher in the Touch vs. SB3 by about 6-8 dB (remember, it's still down at -90dB).
Notice no significant difference between WiFi and wired through the ethernet.
16-bit audio vs. 24-bit audio. Looks good. Less bass drop-off than the SB3 with my equipment.
Jitter (Dunn J-Test, WiFi):
I guess the only surprise is that the stereo crosstalk is higher in the Touch than the SB3. Otherwise, audio quality seems superior - it can obviously handle 96kHz natively (up to 192kHz with the EDO plug-in as a digital transport), and flatter frequency response especially in the low bass could be audible.
Again, assuming the WiFi strength is reliable and you're not constantly rebuffering, I see no indication that sound quality is negatively impacted by going wireless.
Subjectively, I like the Touch's sound. These days, it powers my bedroom system with SONY amp and Tannoy mX2 bookshelf speakers I got about 10 years ago. For what it is, I can't complain about these analogue output results - very competent! Although you can get better measuring noise floor, dynamic range, etc. with an outboard DAC, the Touch in its stock form is already very impressive and it would be wise to do some A-B testing before thinking an expensive DAC will improve the sound much!
For what you get, the bang-for-the-buck from this little device is fantastic and a shame really that it has been discontinued.