New Audio-gd R-7, R-7HE R-8, R-27, R-27HE, R-28 Flagship Resistor Ladder DACs and DAC/amps
Jun 30, 2017 at 7:43 AM Thread Starter Post #1 of 11,259
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This new DAC replaces the PCM1704-based DACs with dual FPGA-controlled resistor ladder DACs, similar in concept to DACs like the Rockna Wavedream and MSB DACs.

http://www.audio-gd.com/R2R/R2R7/R2R7EN.htm

Each channel uses a resistor ladder consisting of pairs of resistors to improve the tolerance, as individual resistors have too high a tolerance for high-bit rate accuracy. To counter the inherent errors in this method, dual FPGAs are used per channel, similar to how MSB and other high-end manufacturers design their DACs.

One arrived here just a few days ago and initial impressions are similar to those I've experienced before with other resistor-ladder DACs, with the kind of sound that makes one want to listen, especially to acoustic and live music. I've only done a brief comparison to my Yggy, and what came to mind is that the Yggy is a bit more "dry" to the slightly more "liquid" sound of the R2R 7, but it isn't tuned as warm as Audio-gd's previous PCM1704-based flagships.

I'll post more impressions soon.

Audio-gd_R2R-7-D75_7775_.jpg Audio-gd_R2R-7-D75_7776_.jpg Audio-gd_R2R-7-D75_7777_.jpg Audio-gd_R2R-7-D75_7778_.jpg Audio-gd_R2R-7-D75_7779_.jpg Audio-gd_R2R-7-D75_7780_.jpg
 
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Jun 30, 2017 at 8:05 AM Post #2 of 11,259
I have been waiting for this DAC a long time. Pictures are really nice.
The Master 7 Singularity was again an improvement in sound (and features) compared to previous Master 7.
I can see Audio-GD takes a new approach with its R2R DAC and knowing them for a lot of years now I can only say; I can't wait!

Looking forward to your impressions...............
 
Jun 30, 2017 at 6:16 PM Post #5 of 11,259
I am really impressed and excited too. The layout of the r2r sections is clean. I assume it is a sign magnitude design, so that it is able to perform well with low amplitude signals and subtle inflexions. The distorsion graph seems a bit better than that of the S7. It perhaps is even better in comparison with low amplitude signals, who knows.

As Kingwa mentioned, the compensation of the r2r ladder is key, since the resistors will never be accurate enough for a classic ladder. Looking forward fto Currawong's review.
 
Jun 30, 2017 at 7:23 PM Post #6 of 11,259
...One arrived here just a few days ago and initial impressions are similar to those I've experienced before with such DACs, with the kind of sound that makes one want to listen to music. I've only done a brief comparison to my Yggy, and what came to mind is that the Yggy is a bit more "dry" to the slightly more "liquid" sound of the R2R 7.

Look forward to your impressions! The "liquid" nature of this DAC you mentioned vs "dryness" of Yggy is one of the SQ attributes why I prefer my Master 7 and HE-7 Singularity over Yggy. I would like to see comparisons with the latest 1704-based A-Gd DACs (the Singularity versions of M7 or HE-7).
 
Jun 30, 2017 at 9:46 PM Post #8 of 11,259
Looking forward for comparison to holo spring dac
 
Jul 1, 2017 at 12:48 AM Post #9 of 11,259
So far I've been listening to a bit of classical (Decca) using Audirvana Plus feeing the DAC via USB. Out of interest, I tried 2/4x up-sampling (maxxed settings, linear phase) and it sounds a bit less "warm". I would guess that Kingwa uses minimum phase or similar filter. I'm not sure if this is standard, but he included a USB programming interface in the box so supposedly I can upgrade the DSP and FPGAs myself with different firmware. I wouldn't mind swapping the NOS setting for different filters instead.
 
Jul 1, 2017 at 6:53 AM Post #13 of 11,259
I've been waiting for this one. Finally R2R Ladders are getting the recognition they deserve and this time going against the well known Yggdrasil.
 
Jul 1, 2017 at 8:33 AM Post #14 of 11,259
Subscribed. I really like the dynamic sound of the Master 7 and Singularity 7. Makes music come alive versus the drier, analytic DACs. Hope this carries over to R2R S7.
 
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Jul 1, 2017 at 9:16 AM Post #15 of 11,259
The layout of the ladder in the R2R 7 is very interesting. On some Dac i have examined lately, a greater number of resistors is used to make a sign magnitude ladder. Looks like Kingwa is using a trick to make a double 24 bit ladder out of only 72 resistors instead of 96. I don't know if other manufacturers use that trick but i find it very clever, if i understand how it works correctly.

I feel like i am going to buy one soon.
 

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