The DAC-80’s digital input stage operates in an asynchronous mode independent of any timing errors associated with the incoming digital audio stream. The input stage synchronizes the data to an internally referenced timing signal generated by an exceptionally stable circuit. The re-clocking circuit’s accuracy is such that any negative timing errors (jitter) are reduced to near theoretical limits.
Precision Volume Control
A digital 32-bit volume control offers precise channel tracking. Unlike more common digital volume controls operating at 24 or 16-bits, the 32-bit dynamic range of the DAC-80's volume control avoids any loss of low-level resolution.
The analog preamp stage is a "minimalist" design that offers a signal path that approaches a "straight wire with gain" level of performance. Combined with top quality parts and a full 4.0Vrms signal level at the RCA outputs, the preamp section of the DAC-80 ensures that only the purest of analog music signals will ever be presented to your preamplifier.
A 24-bit, 192kHz DAC stage accurately converts digital audio data back to an analog signal at its native sampling rate. No up-sampling or other questionable data manipulation is ever employed.
Note: For Async USB Audio, please refer to the Async USB Audio FAQ and Setup Guide.
The following plots showed exceptionl performance of DAC-80. Please refer to larger images of the measurement plot in the image gallery above.
DAC-80 (yellow color) with the reference oscillator (i.e. a signal generator) under identical conditions: The reference oscillator output is 6 dB higher and the noise floor is lower.
The spikes are the residuals of 60Hz and 120Hz component from AC at -100dB. There is no evident of higher frequency jitter with the even noise spectrum well below -130dB
The above FFT Spectrum plot indicates that jitter side-band performance (i.e., jitter) is extremely good. The primary jitter components close to, and on either side of, the 1kHz test tone are more than –100 dB below the test signal. As such, there is no audible contamination of the source recording. Note: The other, larger components spaced further away and on either side of the 1kHz test signal are harmonic artifacts of the measurement process and are therefore irrelevant. Even so, they are all below –100 dB. Were they real, they too would be inaudible.
This FFT Spectrum plot is close to textbook perfection. All residual artifacts of distortion and/or noise are below -100 dB, with most at, or close to, –120 dB. Therefore all converted signals are free of audible colorations or artifacts that would otherwise mask low-level details in the source recording.
The Frequency Response measurement is among the most familiar to audio enthusiasts. The FR of the DAC-80 is all but perfectly flat. Taken together with a total response from 10Hz to 25kHz within that same 0.25 dB window, one cannot ask for better measurements from any audio product, price notwithstanding.
The DAC-80 THD+N measurement is exceptional. The slope of the plotted line is linear, indicating the absence of non-linear components added by the DAC. The standard THD+N measurement as commonly referenced in the audio industry is indicated at the –0 dB point (at the far right of the graph). As we can see, THD+N is less than .005% – extremely good THD+N performance for any audio component.
Note: The 0.3% THD+N measurement indicated at the –40dB test signal level does not reflect the results of a typical THD+N measurement. As a matter of calculation, THD+N (as a percentage of the total output) increases as the test signal level decreases. The law of percentages tells us that with no test signal present, the THD+N becomes 100%, irrespective of the actual measured voltage value.
*During initial turn on, there may be a brief 'noisy music' at low volume for 2 seconds if the CD/Track is being played while the DAC80 is being power-up and setting up itself.