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Audio-Gd Master 7 - Discrete Fully Balanced DAC (PCM1704) - Page 184

post #2746 of 2758
Quote:
Originally Posted by martin778 View Post
 

Sounds like a tough choice!

I'm using a Squeezebox Touch with TT3.0, EDO (USB output up to 192KHz) and TeraDak PSU as a digital source, digital cable is an Apogee Wyde Eye.

 

The price difference is enormous - I can get around €600 for my Octave but I'll have to buy the Master 7 brand new which costs €2155.

Spending €1555 for a side-grade isn't the most brilliant idea ;)

 

Also the offramp is another $1200, that's a no go. Way out of my budget.

 

+

By the way, what about the Sabre based NFB-7?

 

My goal is extreme resolution in the mid and high range and tight bass (I run a bi-amped JBL hybrid-4343)

The Octave is nice but the mid is a bit pushed forward to my taste, also I miss some sprakle in the highs (NOS?).

 

I won't debate that I2S isn't the ultimate way to go with this dac because it is, but for a while I used the $99 Schiit Wyrd straight into the M7 usb latest version and it was fantastic.

post #2747 of 2758
Quote:
Originally Posted by martin778 View Post
 

 

By the way, what about the Sabre based NFB-7?

 

My goal is extreme resolution in the mid and high range and tight bass (I run a bi-amped JBL hybrid-4343)

The Octave is nice but the mid is a bit pushed forward to my taste, also I miss some sprakle in the highs (NOS?).

 

NFB-7 (USB) will give you more resolution, more delineated attacks, and better bass control than M7 (USB) - at the cost of it sounding more digital - especially on the top end

post #2748 of 2758

So, maybe should I go for the NFB?

 

BTW, is modern USB better than S/PDIF?

post #2749 of 2758
Quote:
Originally Posted by martin778 View Post
 

So, maybe should I go for the NFB?

 

BTW, is modern USB better than S/PDIF?

With the Sabre DACs, yes.

post #2750 of 2758
The Audio-GD NFB1 2015 has a totally different sound character then the Master 7
http://www.modelpromo.nl/Audio-GD_NFB1-2015.htm

it's personal;
If you like dynamic, up front, detailed sound the NFB-1 is the best choice
If you preferre a more rounded, realistic and neutral sound the Master 7 is the better choice

soon i will review the DI2014 interface in combination with I2S and standard USB ports
I shall test all possible combinations, on paper the best connections are:

1) i2S
2) USB
3) coaxial digital (SPDIF)
4) optical digital (SPDIF)
post #2751 of 2758
Quote:
soon i will review the DI2014 interface in combination with I2S and standard USB ports
 

Looking forward to it......

post #2752 of 2758

I have been toying with hifi for 5-6 years now and didn't really believe that much in the "source first" mantra but after a couple of weeks with OR5 and M7 combo I have completely changed opinion on that topic, and I don't even use head-phones.

I want to give a big thanks to Purrin, Dacladder, AlRainbow, ArticNoise and others here on the head-fi forum who has been experimenting with different combinations and shared their thoughts and given so much guidence in this thread amongst other places. I have had equipment from Denon, Cambridge, Lavry, Audiolab, Naim, Accuphase, Dali and Tannoy amonst others and mostly good but I feel that I finally have reached end game with my current setup, which consist of PC w/PPA USB- Empirical Audio Shortblock - EA OR5 w/ all uppgrades / Dynamo PSU - HDMI i2s  - AGD M7 w/ acss-> AGD M1 ->  ATC SCM50ASLT. I was sceptical at first reading about it but nw I know the OR5 really made a significant step up. 

 

Thanks, and happy easter!

post #2753 of 2758

Just following on from what people have been saying re the M7 USB module, I think there may be some flaws with it and bypassing it/disconnecting it seems worthwhile.

 

Had some spare time this morning so I hooked up my scope to the M7 to measure waveforms to quantitatively check different sampling rates, filter settings, oversampling settings, etc (I wasn't particularly satisfied with my past square wave measurements so just wanted to explore that further for my own sake).

 

I didn't really get anywhere re improving my square wave measurements, but I did notice that when I used the USB input (my default input), a 100 Hz sine waveform was visible on the rising and falling edges of my square waves (seemed like amplitude modulation of the square wave edges). The 100 Hz signal was continuously visible when I tested with 96 kHz and 192 kHz .wav files but was only intermittent at 44.1 kHz.

 

It may be a mains harmonic (50 Hz mains in Aus) - and I might test this further. However, the 100 Hz waveform was near negligible when I switched to optical input suggesting that it's related to the USB module only.

 

I also noticed visible jitter when viewing waveforms (USB and optical) - which makes me want to test with I2S input and an external clock source.

 

Edit:

I didn't capture any waveforms at the time, but will do and post them up - I understand most of the above is irrelevant without some pictures.

 

Waveforms for 1 kHz square wave at various sampling rates. M7 jumper settings were default (e.g. 130 dB filter, 8 x OS, PLL on, dither on).

 

Waveform captures were undertaken at 5 ms time resolution so that waveform envelope distortion could be easily seen. 

 

44.1 kHz Optical - No issues. The rising and falling edge 'spikes' you see are acceptable and due to the waveform being band limited.

 

44.1 kHz USB -  Generally fine, however notice intermittent distortion to waveform envelope.

 

44.1 kHz USB - Zoomed in on one channel to better see the distortion/dip.

 

192 kHz Optical - Notice distortion at peaks/envelope of waveform. ~100 Hz sine wave amplitude modulation.

 

192 kHz Optical - Zoomed in one channel. Distortion, ~80 mVolts peak-peak.

 

192 kHz USB - Distortion is more evident/more pronounced.

 

192 kHz USB - Zoomed in on one channel. Distortion ~110 mVolts peak-peak.

 

Based on the above, I think the optical input is better than the USB. There seems to be intermittent glitching/distortion issue with USB at 44.1 kHz which doesn't occur with optical. And both suffer from the AM distortion issue, but it is measurably less with optical. 

 

I am not sure on the reason for the AM distortion which seems to appear at frequencies > 44.1 Khz and get worst with higher sample rates. If it were a mains/ground loop issue, I'd think it would appear at all times, irrespective of sample rate?

 

I thought maybe the USB module was causing this problem based on reports from some to disable the USB module - but when I unplugged the USB module, the distortion remained when using optical.

 

I was also unable to EQ out the 100 Hz signal (thought I'd try it).

 

Maybe the distortion is being added by the DSP. Guess the next things to try are:

1. Bypass mode (bypass the DSP)

2. Different filter settings

 

Note, I'm also fully aware that the distortion could be due to my setup too. I don't have any power conditioning, and when on USB, I'm connecting directly from laptop USB (noisy)... just odd that I'm getting various degrees of distortion with different variables.


Edited by aive - 4/5/15 at 7:34pm
post #2754 of 2758

I wonder, with the mention of the NFB-7 sounding more digital, if it wouldn't work best with a computer running software that has iZotope up-sampling to 352.8 kHz or 384 kHz? I say this because other Sabre-based DACs I've tried sound considerably less "digital" when I've tried it with Audirvana Plus.

post #2755 of 2758
Quote:
Originally Posted by aive View Post
 

Maybe the distortion is being added by the DSP. Guess the next things to try are:

1. Bypass mode (bypass the DSP)

2. Different filter settings

Also try an audio tone frequency that is not integer divisible by 50Hz like 133Hz.  In this case if it is power supply ripple then perhaps the noise will be seen on the scope floating through the waveform display (i.e. not locked to the 133Hz tone).  Could be artifacts of the digital filter as well trying to reproduce sq. waves. 


Edited by DACLadder - 4/6/15 at 7:17am
post #2756 of 2758

My experience with removing the USB module completely does help with "cleaning up"(Can't think of a better world to describe what I experienced) the sound. Not sure if you can really capture it with instrumentation, especially when you have so many additional electrical noise in the chain. In this case, you should experiment with/without usb module and trust your ears as this is a total reversible process and doesn't cost you anything(except time and some energy)

 

Hopefully Kingwa will offer a new revision of the USB Module in the future, with improved sound and better driver/firmware.


Edited by evillamer - 4/8/15 at 5:38pm
post #2757 of 2758

Anyone have DI-2014/ Master 7 listening impressions?... Compared to USB32, OR5, ...?   

post #2758 of 2758
Quote:
Originally Posted by DACLadder View Post
 

Anyone have DI-2014/ Master 7 listening impressions?... Compared to USB32, OR5, ...?   

Here you go

 

http://www.head-fi.org/t/625793/audio-gd-master-7-discrete-fully-balanced-dac-pcm1704/2325#post_11099115

 

Frizzup

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