Dac Metrum PAVANE

[Janacek]

Bonjour

J'ouvre un thread sur les DAC Metrum, suite aux post de R11bordo au sujet des DAC avec le R2R et l’exemple des Metrum, dans le thread Denafrips.

(10-29-2018, 10:53 PM)r11bordo a écrit : Hello
Sur photo, le Terminator semble bien porter son nom. Pourtant, un ancien de ce forum décrit les dac r2r comme mous du genou, et avoue avoir eu une expérience mitigée avec ce type de dac (en tout cas, il a revendu ses dacs r2r à pas de prix, trop plan plan selon lui). 
Je me demandais donc si le Terminator s'adresse davantage un public proche de la retraite, adepte de la musique de chambre et des écoutes intimistes, à faible volume sonore, ou est ce au contraire un appareil homogène sachant restituer le rythme d'une œuvre funky ou rock des seventies ?

En plus du test de Patatorz très bien fait et interesant.

(10-30-2018, 10:18 AM)r11bordo a écrit : C'est l'Amethyst
http://patatorz.com/2018/10/27/metrum-ac...mpathique/

Je suis sur le site de Metrum
Il y a le Pavane 4 850,00€ hors TVA soit 5 868,00€ plus de 25€ avec Poste NL à 120€ avec UPS + douane...
ça pique ehhh....
https://metrumacoustics.com/product/pava...acoustics/

Citation :With the goal of creating a very special DAC in mind the designers of Metrum Acoustics have developed a new DAC.
It was an unprecedented challenge, which was eventually solved by introducing an entirely new chip, which has been exclusively developed by Metrum Acoustics.
Behind the luxurious front more than new chips are concealed:
The parallel driven R2R ladder networks as used in the eight DAC modules performs , especially when combined with our FPGA-driven “forward correction module”, on a higher level. This module splits up the audio samples for each channel into new separate data streams. Each dac cluster processes a portion of the data in the most linear region of the dac chips. The result of this process is an extremely high linearity, right down to -140 dB, which gives the Pavane a realistic 24 bit dynamic range. Due to the dual mono design over the entire frequency range an extremely high channel separation of 120 dB is realized. This contributes to the flawless positioning of instruments.
In short, the Pavane is a DAC that has taken all the lessons and experiences that her designer has learned over the years, and combined them in an ambitious DAC that can fit in every system. It is musical, honors the Non-oversampling principle while simultaneously incorporating the technological progress that has been made over the years.

Citation :Extreme NOS
The Pavane by Metrum Acoustics Pavane is the company’s flagship DAC.
The Forward correction module is splitting the 24 bit format into two new 12 bit streams. So you have a 12 bit stream which is the LSB (least significant bits) and the 12 bit DAC (most significant bits). The problem with 24 bits R2R ladder DAC is linearity and switching noise of the ladder network in the lower ranges. Therefore the LSB part will be pushed to the upper part of the ladder by the forward correction module. In other words, the LSB will be processed as MSB data. The advantage is that it will be processed in the area having the lowest noise, the best linearity and the lowest distortion.
The result however is that on the analog side of these two clusters the volume of the LSB is equal to the MSB part which is wrong, of course. Therefore we have to attenuate the LSB part with 67 dB (equal to 12 bits) to let it match with the MSB part. The result of this attenuation is that switching noise is also attenuated for 67dB and that distortion and linearity in this range is the same as in the MSB part.
All incoming data is passed through this “forward correction module” and the answer to “What’s it correcting?” is essentially low level linearity and noise.
The USB receiver comes courtesy of M2TECH’s hiFaceTWO that supports up to 384kHz over I²S, which is fed directly to the FPGA. The Toslink input maxes out at 96kHz, while the Coax and AES inputs can handle up to 192kHz PCM data. Finishing off the back panel are the power switch and the IEC inlet for the included power cord. Up front resides the units On/Standby button and a series of buttons with associated blue LEDs for input selection.

et le Onyx moins cher 2 495€ TVA inclus et fdp voir Pavane + douane....
https://metrumacoustics.com/product/pava...acoustics/

Citation :With the goal of creating a very affordable, yet superior DAC in mind the designers of Metrum Acoustics have developed a new DAC, the ONYX By Metrum Acoustics.
It was an unprecedented challenge, which was eventually solved by using an entirely new chip, which has been exclusively developed by Metrum Acoustics and was first used in the PAVANE.
The parallel driven R2R ladder networks as used in the four DAC modules performs , especially when combined with our FPGA-driven “forward correction module”, on a higher level. This module splits up the audio samples for each channel into new separate data streams. Each dac cluster processes a portion of the data in the most linear region of the dac chips. The result of this process is an extremely high linearity, right down to -140 dB, which gives the ONYX a realistic 24 bit dynamic range. Due to the dual mono design over the entire frequency range an extremely high channel separation of 120 dB is realized. This contributes to the flawless positioning of instruments.
In short, the ONYX is a DAC that has taken all the lessons and experiences that her designer has learned over the years, and combined them in an ambitious DAC that can fit in every system. It is musical, honors the Non-oversampling principle while simultaneously incorporating the technological progress that has been made over the years.

Je vois que aussi dans les Metrum parle des R2R.....mais en NOS?

PS l'entrée USB peut-être remplacé par un entrée I2S. Si achete avec le DAC est gratuit. Je imagine que cette entrée fonctionne uniquement avec le Amber de Metrum et pas d'autres streamer....


EDIT
mon CR sur le DAC page 4.