dqwong
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I have been researching alot into DAC(AKM/Crystal Semiconductor/ESS/Ti/Wolfson) and here's some interesting quotes I found from Charles Hansen(Founder and Designer) of Ayre Acoustics
source:
Q&A with Charles Hansen of Ayre Acoustics | AudioStream
source:
Oversampling: Who Does It Best? - Page 5
As time went on, the main demand has been for smaller, cheaper DAC chips with lower power consumption. This is due to the iPod craze. There is still a market for high-performance audio DAC chips, but there are only a handful left. All but one (the Burr-Brown PCM1704) use some form of a delta-sigma design that typically has only one to six bits, and relies on oversampling and noise shaping to attain reasonable performance.
In general, the more bits it has, the better the performance will be. However with a ladder DAC, all of the bits beyond 18 or so are called "marketing bits" as there is no audio-grade ladder that can exceed 18 bits of resolution. For example when Burr-Brown replaced the "20-bit" PCM1702 with the "24-bit" PCM1704, not one single specification changed. The only difference was that you could feed it digital words that were 24 bits long.
source:
Q&A with Charles Hansen of Ayre Acoustics | AudioStream
The Analog Devices AD1955 is essentially similar to the Burr-Brown devices. The Cirrus Logic CS4398 has a switched-capacitor analog stage, which in conjunction with an internal op-amp provides a voltage output. I have never been a fan of op-amps. The AKM AK4396 is similar to the Cirrus Logic part except that it has a patented method (6,693,574) of canceling some of the out-of-band noise created by the sigma-delta modulator. Some people, particularly Alex Peychev of the now defunct APL Labs, loved this part for that reason.
None of these parts provides any better low-level resolution than the Burr-Brown parts.
The ESS9018 is all the rage these days among certain people. The DAC section itself performs comparably to the PCM1792. However, the chip has a smorgasbord of other functions built in -- asynchronous sample rate converter, programmable digital filter, 8 channels of DACs (for easy design of a 7.1 channel receiver), and a multi-input S/PDIF receiver. Consequently, this part is expensive -- nearly 4x the price of the PCM1792. Since I don't need those other functions I don't feel that it offers a good value for my needs.
The AK4399 is similar to the AK4396, but is a "32-bit" part. This was probably the first of the "32-bit" parts. The specs are not improved over the 24-bit parts, it is simply a marketing gimmick that produces little, if any, audible improvement.
source:
Oversampling: Who Does It Best? - Page 5
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