RMAF 11: Noise Shaping Sigma Delta Based Dacs, Martin Mallison, CTO, ESS Technology - YouTube
The above link shows a youtube video of an ESS presentation at RMAF. I encourage everybody to watch it.
It details advances ESS claim in the design of their sigma-delta DACs.
Foremost in the claims is the fact that some people can evidently hear features well below the noise floor which were previously held by the majority of engineers to be inaudible. This is said to be confirmed in blind testing.
Large changes in the values of variables in the state space are said to contribute to non-periodic steady-state noise normally invisible using conventional measurement techniques. This is visible when instrumentation is used to examine the Noise-vs-DC Offset.
This is said to be minimized in ESS products by techniques designed to control the state-space related noise by rapidly quenching state variable excursions.
ESS also claim that a further artifact of sigma-delta modulators, variable (non-linear) excess phase, which causes oscillation in S-D modulators, has been eliminated by making their devices unconditionally stable, and that this too contributes to greater acceptance of the devices by some listeners, although the reasons for this are apparently not clearly understood.
The above link shows a youtube video of an ESS presentation at RMAF. I encourage everybody to watch it.
It details advances ESS claim in the design of their sigma-delta DACs.
Foremost in the claims is the fact that some people can evidently hear features well below the noise floor which were previously held by the majority of engineers to be inaudible. This is said to be confirmed in blind testing.
Large changes in the values of variables in the state space are said to contribute to non-periodic steady-state noise normally invisible using conventional measurement techniques. This is visible when instrumentation is used to examine the Noise-vs-DC Offset.
This is said to be minimized in ESS products by techniques designed to control the state-space related noise by rapidly quenching state variable excursions.
ESS also claim that a further artifact of sigma-delta modulators, variable (non-linear) excess phase, which causes oscillation in S-D modulators, has been eliminated by making their devices unconditionally stable, and that this too contributes to greater acceptance of the devices by some listeners, although the reasons for this are apparently not clearly understood.
yes, old news.
luckily they already have the highest performance SD dac part available for several years =) ie. they are not replacing engineering with psuedo-science
luckily they already have the highest performance SD dac part available for several years =) ie. they are not replacing engineering with psuedo-science
I concur cc, its an excellent one and Martin Mallinson makes a great presenter of the material.
There are several caveats though - in particular one of the slides they present comparing their offering to ADI's has vastly different vertical axes so highly misleading.
They also omit to give details of what the 'reference' DAC was that their 'golden eared' listeners used in the development of the Sabre DAC.
Lastly, its clear from measurements of the Medea+ DAC (by Weiss) that the Sabre DAC suffers from noise modulation. One can only assume that they missed out in optimizing this aspect of their modulator. Or perhaps the noise modulation occurs in the DWA algorithm later down the signal chain. Discussion of DWA techniques also wasn't included in the presentation.
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