LABORATORY TEST REPORT

Given the unusual digital-to-analogue processing used in the APL Hi-Fi DSDAR, I was expecting some unusual results back from Newport Test Labs, and that’s certainly what I received. Graph 1 shows the APL Hi-Fi DSD-AR’s analogue output when it’s fed with a 1kHz sine wave at maximum level (0dB). Obviously there’s more distortion than I’d expect to see, but much of the distortion that’s there is not actually harmonically related to the 1kHz test signal.

There’s a second harmonic at –95dB (0.0017%), and a third at –78dB (0.0125%), a fourth at –120dB (0.0001%) and a fifth at –102dB (0.0007%). All the other harmonically-related distortion components are more than 110dB down, each representing