11 November 2013

Black Lion “Sparrow” DAC

The Sparrow is a stereo D/A capable of operation to 192kHz, with AES,

optical, and S/PDIF inputs. Construction is primarily surface-mount, with a large number of through-hole electrolytic capacitors also seen. The converter chip is the ESS9018.

I/V conversion is AD797 with LM4562’s and AD8510’s also used, presumably

in the anti-image and line output stages. A linear PSU with toriodial transformer and ferrite EMI “clamp” filters are used. Figures 1 and 2 show the front and back of the PCB.

Measured performance agrees well with manufacturers specifications of

0.0005% (-105) THD+N at -10dBFS (1kHz, 20-22k filter, 96kHz input, +18dBu output) and 0.0015% SMPTE IMD.

THD+N at 0dBFS is roughly -103dB. A comparison was made to the ESS 9018 SABRE_8 2 channel D/A evaluation

board.

Figures 3 and 4 compare the Sparrow to the ESS reference design at 1kHz/0dBFS (fundamental removed).

Figures 5 and 6 compare the Sparrow with the ESS reference design. The FFT of 19kHz/20kHz at 0dBFS shows substantial harmonic content not

present in the ESS evaluation board.

The source of this inter-modulation is not known, but is almost certainly the cause of audible distortion during the listening tests.

Other measurements not shown here (Noise, dynamic range, THD vs. level)

are all superior in the ESS reference design.

F igur e 1. Spar r ow PCB Top

F igur e 2. Spar r ow PCB Bottom

F igur e 3. Spar r ow 1kHz at 0 dBF S

F igur e 4. ESS Re fe r e nce De sign 1kHz at 0 dBF S

F igur e 5. Spar r ow 19k/ 20 k at 0 dBF S

F igur e 6. ESS Re fe r e nce De sign 19k/ 20 k 0 dBF S