This is an old DAC utilizing dual-differential Burr-Brown PCM-63 chips with digital volume control. Released in the late 90's, Uther supports HDCD format, has balanced audio output, selectable dither and a large number and type of digital inputs, from I2S to Toslink to AES/EBU and coax SPDIF and AT&T glass. Powered by an external proprietary power supply, some versions of the DAC also came with a rechargeable battery. This one did not, and was tested from its personal power supply, which appears to perform extremely well with no leaking frequencies.
A quick set of measurements to gauge how well Uther2 performs. Fed by a 20/44.1kHz dithered signal, measured alternatively at 24/192k or 24/44.1k by Apogee Element24. Toslink SPDIF input was used for all tests.
1kHz measurement shows THD of -91dB and THD+N of -88dB. Third harmonic is just below -100dB level, although 7th and 9th are almost at that same level:
Multitone test:
CCIF IMD test:
DIN IMD test:
Frequency and phase response:
White noise response showing the reconstruction filter:
Jitter at 12kHz is fairly low:
Distortion vs Frequency shows a rising 3rd and 2nd harmonics, while noise floor remains pretty much flat:
And an extended bandwidth measurement of a 10-22k sine sweep playing:
Simulated silence (-120dB sine wave) looks like this:
A quick set of measurements to gauge how well Uther2 performs. Fed by a 20/44.1kHz dithered signal, measured alternatively at 24/192k or 24/44.1k by Apogee Element24. Toslink SPDIF input was used for all tests.
1kHz measurement shows THD of -91dB and THD+N of -88dB. Third harmonic is just below -100dB level, although 7th and 9th are almost at that same level:
Multitone test:
CCIF IMD test:
DIN IMD test:
Frequency and phase response:
White noise response showing the reconstruction filter:
Jitter at 12kHz is fairly low:
Distortion vs Frequency shows a rising 3rd and 2nd harmonics, while noise floor remains pretty much flat:
And an extended bandwidth measurement of a 10-22k sine sweep playing:
Simulated silence (-120dB sine wave) looks like this:
