nitewulf: I believe that the Comet is Delta Sigma, but Merlot is FPGA. And Metrum uses proprietary R2R chips.
I love my PS Audio Direct Stream with Red Cloud :)
Yesterday, PS Audio released the Red Cloud FPGA software written by MIT genius
Ted Smith.
With immense delight, I auditioned all through the night.
The beauty exceeds what were my wildest expectations when I purchased the DAC
several years ago, and reconfirmed that I had made another good choice (my
previous good choices include Tannoy 15" DC speakers, Cary SLP05 preamp,
Art Audio Jota HC monoblocks, Wavelength Cardinal monoblocks, Cardas Clear
cables, Acoustic Zen reference cables, Wyred4Sound server, PS Audio Premier
Power Plant, inexpensive HDMI cable, and ceramic corn dishes.
While I haven't heard a great many DACs, I have heard static-state Sabre DACs,
which sound ear-bleeding mediocre IME, and R2R chips which were the thing 20+
years ago. I think that FPGA Red Cloud is superior, and the best thing
aesthetically to have come from a scientist educated at MIT. Make music, not
war.
Disclaimer: I'm not affiliated with PS Audio, except as a happy customer. It's
just a great company!
- ...
- 34 posts total
According to Exogal CEO Jeff Haagenstad in conversation with Michael Lavorgna of Audiostream: "The longer version is that we don't do our D to A conversion in a conventional way. We have implemented a 6-core DSP in an FPGA (and we blew the "Read" bit, so we can write to it for upgrades but it can't be read or decompiled...) and we use some signal processing approaches that are unconventional in audio but not in wider signal processing work." "The EXOGAL DSP platform (on which the Comet is the first of many products to exploit the technology) does have some conventional DAC chips but only the final output stages of the DAC chips are used for the final translation into analog. The main output uses PCM4104 DAC's and the headphones use PCM5122 DAC's. The outputs are buffered using TI/National LME49600 buffers. These are high-current, high-impedance, class AB buffers with no feedback. Beyond that, we ain't sayin' " Read more at https://www.audiostream.com/content/exogal-comet-dac#zHAKuQUy8iV0yglU.99 |
Metrum is r2r, but there's FPGA processing: http://www.the-ear.net/review-hardware/metrum-acoustics-adagio-dacpreamplifier "New to the Adagio are Transient DAC Two modules, a further development of the Transient and FPGA architecture used in the Pavane DAC. Inside each module are two 16-bit R2R ladder converters and one FPGA. When a 16 to 24 bit signal enters the module it is split into two sections by the FPGA. The upper bits are passed directly to one of the R2R converters, while the lower bits are raised to the highest level before they reach the second R2R converter. This increase in level is done so as to use the highest voltage on the ladder resistors, moving away from the relativel noisy, low level signal part that exists in all types of converter. Before the output stage the signal level of the second converter needs to be adjusted to the correct level and combined with the original upper part to create the correct output signal. Metrum manipulates the least significant bits (LSB) because lower level irregularities occur, non-linearity arises and digital noise becomes part of the analogue signal with lower level signals. These modules reduce noise by -145dB or more. This might sound simple but it took years to write the algorithms for the FPGA and to develop the Transient DAC Two R2R converters." Not to stray too off topic though, PS Audio dacs are great, was just wondering what other dacs use fpga processing. |
- 34 posts total