Audio-Gd Master 7 - Discrete Fully Balanced DAC (PCM1704)
Sep 28, 2018 at 3:45 PM Post #4,036 of 4,451
Hello seaice! The HDMI I2S signalling is not compatible with AGD inputs. It is like the Gustard U12 where resulting absolute audio phase is 180 deg. plus L- R channels are swapped.

Hi DACLadder, thanks again, very good info! My MScaler>HE7S mission is probably doomed. I doubt that a device converting 352.8/384kHz SPDIF to A-GD I2S exists .
 
Oct 5, 2018 at 1:26 PM Post #4,037 of 4,451
After three months with the R2R 7 and the last Singularity V2 firmware whirlwind I took some time off from listening to music and, for some kicks, returned to the SIngularity 7 (M7S). I like V2A Accurate version with this DAC. Adds much needed clarity in the highs versus Smooth. All three versions sound pretty good though and can appreciate one or other based upon listening preference. But I tend to like V2 Smooth with the R2R 7 as it provides better balanced on my system (less highs and more bass). OS x8 DSP setting on both and identical SIngxer F1 sources.

The Master 7 DACs are very dynamic and slightly more so than the R2R 7. I can immediately hear more bass on music that is lively and with a beat. Always appreciate this fact with the M7S. The M7S can throw a wide stage as well. The R2R 7 has slightly better highs and a tiny amount more low-level resolution. The R2R 7 is probably more accurate but the M7S can render music (a touch warmer) that is very enjoyable. And yet M7S and R2R 7 are cut from the same cloth with only minor differences in sound quality.
 
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Oct 8, 2018 at 6:32 AM Post #4,038 of 4,451
Hi
I want rolling dc servo opamps in master 7 and master 1
I have opa2132, opa2107, lm4562, lme 49860 opamps to test
My favorite one is opa2107 , that is difet , simillar to opa627 and sound very rich
But I have a question
M7 is connected to M1 by ACSS connection
So does it matter to change M7 opamps or in acss connection M7 opamps are bypassed?
 
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Oct 8, 2018 at 7:29 AM Post #4,039 of 4,451
Hi
I want to roll-off dc servo opamps in master 7 and master 1
I have opa2132, opa2107, lm4562, lme 49860 opamps to test
My favorite one is opa2107 , that is difet , simillar to opa627 and sound very rich
But I have a question
M7 is connected to M1 by ACSS connection
So does it matter to change M7 opamps or in acss connection M7 opamps are bypassed?
The opamps have minimal effect on sound as they are used only to cancel the dc offset. Not all opamps can be used for that purpose. The 2132p will do. With the m7, i believe the opamps are soldered to the boards so they can’t be swapped. As far as i know, the opamps are not bypassed with acss.
 
Oct 8, 2018 at 8:05 AM Post #4,040 of 4,451
Than
The opamps have minimal effect on sound as they are used only to cancel the dc offset. Not all opamps can be used for that purpose. The 2132p will do. With the m7, i believe the opamps are soldered to the boards so they can’t be swapped. As far as i know, the opamps are not bypassed with acss.
Thanks FredA
You are always responsive, kind and informative
I really appreciate that
Yep, you are right, for dc servo opamp must be fast and low dc offset exist in inputs , as I know (correct me if I am wrong)
So, kingwa use opa2134 which slewrate is 20v/us and dc offset typically is about 0.5 mv and max 2mv
2107 slew rate is 18v/us , quiet close to 2134 and dc offset is typically 0.1 mv and max 1 mv
Yes, opamp in one of M1 and M7 is (I dont remember exactly which one) soldered directly to the board
Did you test rolling opamps by yourself or not?
 
Oct 8, 2018 at 9:12 AM Post #4,041 of 4,451
Than

Thanks FredA
You are always responsive, kind and informative
I really appreciate that
Yep, you are right, for dc servo opamp must be fast and low dc offset exist in inputs , as I know (correct me if I am wrong)
So, kingwa use opa2134 which slewrate is 20v/us and dc offset typically is about 0.5 mv and max 2mv
2107 slew rate is 18v/us , quiet close to 2134 and dc offset is typically 0.1 mv and max 1 mv
Yes, opamp in one of M1 and M7 is (I dont remember exactly which one) soldered directly to the board
Did you test rolling opamps by yourself or not?

You’re welcome.

I just tried the 2132p, that’s it, as recommended by @JaMo. I got a slight upgrade with overall clarity.
 
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Oct 9, 2018 at 6:48 AM Post #4,043 of 4,451
Hi Fred,
Not completely true. I suggested/recommended OPA2140's. They are the best I found for the servo-job
/Jan
Hi Jan.
Yes, my memory plays tricks on me. Another headfier recommended the 2132p. I think the 2140 has to be put on adapters, as it is smd. And it is more expensive.
 
Nov 8, 2018 at 9:06 PM Post #4,046 of 4,451
For limited time till 11th Nov, audio-gd accepts order of M7S and HE7S. I have just placed my order for a M7S. I chose the M7S over the R7 mainly for quicker warm up time.
 
Nov 8, 2018 at 9:22 PM Post #4,048 of 4,451
Congrats! I think you could request the new faceplate with settings. Just a thought.

I think the new front end panel is only for converting R2R7 to R7? Cause Kingwa only mentioned the USB isolator input with built in power supply being the only upgrade since the last M7S. From my experience with the Reference 5.32, I don't care much about changing setting, as I would set it permanently to OS8X, PLL on and Dither on. I don't like NOS with the PCM1704.

I did request to have the DC Servo opamps to be installed on sockets though.
 
Nov 8, 2018 at 9:27 PM Post #4,049 of 4,451
I think the new front end panel is only for converting R2R7 to R7? Cause Kingwa only mentioned the USB isolator input with built in power supply being the only upgrade since the last M7S. From my experience with the Reference 5.32, I don't care much about changing setting, as I would set it permanently to OS8X, PLL on and Dither on. I don't like NOS with the PCM1704.

I did request to have the DC Servo opamps to be installed on sockets though.
Using the r-7 fw, i suppose it would work as is. Good idea for the opamps. I did not like nos so much with v1, did not even try it with v2a, but with v3a, i am enjoying nos2 a lot.
 
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Nov 8, 2018 at 9:37 PM Post #4,050 of 4,451
Using the r-7 fw, i suppose it would work as is. Good idea for the opamps. I did not like nos so much with v1, did not even try it with v2a, but with v3a, i am enjoying nos2 a lot.

I also requested to have V3A firmware preloaded (hopefully it is already available). The funny thing is I had bought a USB Blaster for doing Reference 5.32 firmware upgrade before, but had misplaced it somewhere in the storage. I don't want spending hours digging up the USB Blaster again...
 
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