1/20/2024 0 Comments Dragonfly cobalt power output![]() This graph was taken with the DragonFly Red driven by the MacBook Pro and it turned out that behavior was due to an interaction between the Audio Precision's input stage and the Red's ESS headphone amplifier. When I fed it 16-bit J-Test data, the lowest-frequency sidebands, at ☒29Hz, were slightly accentuated (fig.14 the correct levels are shown by the green line) of more concern was the symmetrical modulation of the noise floor just over 3kHz to either side of the spectral spike that represents the high-level tone at one-quarter the sample rate. The Black's reconstruction filter offers similar rejection above the audioband (fig.3), but the harmonics of the 19.1kHz tone are all higher in level, at ≥7dB (0.14%).įig.13 AudioQuest DragonFly Red, 24-bit data, HF intermodulation spectrum, DC≣0kHz, 19+20kHz at 0dBFS into 300 ohms, 44.1kHz data (left channel blue, right red linear frequency scale).Įven after 36 hours of burn-in, the DragonFly Red's rejection of word-clock jitter was disappointing. This graph was taken with the Red, and the harmonics associated with the 19.1kHz tone all lie below ≨0dB. ![]() Both DragonFlys preserved absolute polarity ( ie, were non-inverting), and both offered a very low output impedance of 110dB. The DragonFlys' maximum output levels at 1kHz into a high 100k ohms load were 1.19V (Black) and 2.04V (Red). AudioQuest's Stephen Mejias warned me that the DragonFlys' rejection of jitter would be optimized after they'd been powered up for 24 hours, so before I did any testing, I left both plugged into USB ports on one of the PCs in my lab for 36 hours.Īpple's USB Prober utility identified the DragonFlys as "AudioQuest DragonFly Red v1.0" and "AudioQuest DragonFly Black v1.5," both from "AudioQuest." Both converters' USB ports operated in the optimal isochronous asynchronous mode, and Apple's AudioMIDI utility revealed that they accepted 24-bit integer data sampled at all rates from 44.1 to 96kHz. I then repeated some of the testing, playing the same files with Pure Music 3.0 on my MacBook Pro running on battery power, and on my iPhone 6 using a Lightning-to-USB adapter. I performed a full set of tests on both converters with WAV and AIFF test-tone files sourced from an iPad 2 with a 30-pin-to-USB "camera connection kit" adapter. ![]() I measured the AudioQuest DragonFly Red and Black with my Audio Precision SYS2722 system (see the January 2008 " As We See It").
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