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Meaning of Dynamic Range for Vekian DAC
Meaning of Dynamic Range for the Vekian DAC
In general, Dynamic Range is the window or difference between the
maximum reproducible signal to the lowest reproducible signal that at or just slightly above the background noise level. For digital, the
theoretical dynamic range is determined by the number of n-bits with
quantization levels of equal distance or DR(db)=20log10 * (2^n) or
approximately 6.02*n. This would mean 16-bit digital audio would
have maximum theoretical limit of about 96dB, 20-bit would be 120dB, and 24-bit would be 144dB.
But, in reality dynamic range is limited by factors that can raise the noise floor such as quantization errors, semiconductor non-linearities, semiconductor noise sources, background thermal noise in passive components, and etc. The general standard (EIAJ) measurement for dynamic range is to measure the
absolute value of the total harmonic distortion (THD+N) plus 60dB
with a 1kHz input signal at an input level of -60dB. In addition,
the standard specifies the measured spectrum is band-limited to the
Nyquist frequency, otherwise out-of-band noise can corrupt the
dynamic range noise results due to aliasing components and the
dynamic range noise measurements are A-weighted.
The maximum dynamic range for the Vekian's digital-to-analog converters set at the maximum gain with the output voltage at 6.5Vrms and the corresponding fs = 44.1kHz, 96 kHz, and 192 kHz respectively was determined from measurements and calculation to be 130dB. The THD+N at Vout=0dB is less than 0.0004%. However, compensating for the 1.9dB noise factor of the analog gain stages, the dynamic range of the Vekian was conservatively rated for 127dB at the balanced output. The lowest determined dynamic range is conservatively rated at 123dB at the unbalance output connection with the low gain setting determining the maximum output voltage of 1.63Vrms.
In general, Dynamic Range is the window or difference between the
maximum reproducible signal to the lowest reproducible signal that at or just slightly above the background noise level. For digital, the
theoretical dynamic range is determined by the number of n-bits with
quantization levels of equal distance or DR(db)=20log10 * (2^n) or
approximately 6.02*n. This would mean 16-bit digital audio would
have maximum theoretical limit of about 96dB, 20-bit would be 120dB, and 24-bit would be 144dB.
But, in reality dynamic range is limited by factors that can raise the noise floor such as quantization errors, semiconductor non-linearities, semiconductor noise sources, background thermal noise in passive components, and etc. The general standard (EIAJ) measurement for dynamic range is to measure the
absolute value of the total harmonic distortion (THD+N) plus 60dB
with a 1kHz input signal at an input level of -60dB. In addition,
the standard specifies the measured spectrum is band-limited to the
Nyquist frequency, otherwise out-of-band noise can corrupt the
dynamic range noise results due to aliasing components and the
dynamic range noise measurements are A-weighted.
The maximum dynamic range for the Vekian's digital-to-analog converters set at the maximum gain with the output voltage at 6.5Vrms and the corresponding fs = 44.1kHz, 96 kHz, and 192 kHz respectively was determined from measurements and calculation to be 130dB. The THD+N at Vout=0dB is less than 0.0004%. However, compensating for the 1.9dB noise factor of the analog gain stages, the dynamic range of the Vekian was conservatively rated for 127dB at the balanced output. The lowest determined dynamic range is conservatively rated at 123dB at the unbalance output connection with the low gain setting determining the maximum output voltage of 1.63Vrms.
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