[jacal01]

Yeah, I'm currently of the opinion that oversampling is a good thing, and that the quality of the digital filter employed (no. of filter taps, closed form algorithm) has a significant impact.  I believe that the PCM1704 uses the associated DF1704 digital filter (8x oversampling, selectable).

 

[DACLadder]

  Yeah, I'm currently of the opinion that oversampling is a good thing, and that the quality of the digital filter employed (no. of filter taps, closed form algorithm) has a significant impact.  I believe that the PCM1704 uses the associated DF1704 digital filter (8x oversampling, selectable).

Oversampling can be a good thing if properly implemented.   I'm sure eventually that I will get around to trying different M7 oversampling rates and filters but in no hurry.  I always reflect back to John Darko's review of the AGD Reference 7.1.  What I remember of the review is the Ref 7.1 took forever to burn in and after 6 months John contacted Kingwa about changing the filters and oversampling.   Kingwa said basically go ahead and try but 8X sounds best.  And John agreed after some eval time. 
 
The M7 doesn't use the DF1704 oversampling filter chip.   Those functions done by the DSP which is nice as you have more options plus can change the algorithms if needed.

 

[jacal01]

Interesting.  Who wrote the filter algorithms programmed in the DSP?  Kingwa?  Are there canned interpolation filter programs?

 

[wmedrz]

I'm considering the M7 and noticed there are two versions available, the RJ45 + HDMI and the USB. The HDMI version comes with the digital interface at a discount. Which would you guys recommend and why? From my understanding the USB interface on the M7 has been improved with software this year. Will the RJ45 be a significant step over USB? Is he HDMI a step above the RJ45? 

 

[aljordan]

  Interesting.  Who wrote the filter algorithms programmed in the DSP?  Kingwa?  Are there canned interpolation filter programs?

I remember a couple years ago reading that he had contracted the programming of the DSP out to an external subject matter expert, but I can't recall where I read it.

 

[jacal01]

  I'm considering the M7 and noticed there are two versions available, the RJ45 + HDMI and the USB. The HDMI version comes with the digital interface at a discount. Which would you guys recommend and why? From my understanding the USB interface on the M7 has been improved with software this year. Will the RJ45 be a significant step over USB? Is he HDMI a step above the RJ45?

 
I'm not conversant about the latest USB driver version , but I can say that the LVDS I2S via HDMI input is better than S/PDIF and LVTTL I2S via RJ45. But you need that pesky (spelled $$) OR5 USB DDC on the front end for best results.

 

[DACLadder]

  I'm considering the M7 and noticed there are two versions available, the RJ45 + HDMI and the USB. The HDMI version comes with the digital interface at a discount. Which would you guys recommend and why? From my understanding the USB interface on the M7 has been improved with software this year. Will the RJ45 be a significant step over USB? Is he HDMI a step above the RJ45? 

 
Audio GD is currently running a special 50% off discount of the DI-2014 with purchase of a Master 7.   For $160.00 you can get the tricked out DI-2014 with HDMI and TCXOs . 
 
If it were me I would only get RJ45 I2S if I had a source that already provided that output.   And I would pick HDMI over RJ45 I2S for better sound quality.  I haven't connected USB32 or RJ45 I2S in a while so can't help there. 

 

[frizzup]

My setup is
Jplay,
Audiphils Optimizer,
Windows 2012 R2 Core,
Intel I7 Control & Audio PC's
Paul Pang Clock Upgraded ASUS Motherboards
SSD's Battery powered
Meicord Cat 7 Ethernet Cable
2 x HDPlex 100W Linear Power Supplies 12V to CPU's and 19V to motherboards
Paul Pang USB V2 USB PCIE card battery powered
Double Helix USB cable
Audio-GD DI-2014, TXCO, HDMI/I2S kit installed
Wireworld V7 Silver Starlight HDMI
Audio-GD M7, with HDMI/I2S DIY Kit replacing RJ45 input
Double Helix Balanced ACSS Cables
Audio-GD M10
Mad Scientist NEO Power Cord and Inline Purifer on the M10
Audioquest 16/4 cables
Magnepan 3.7R's
 
Assembled this equipment a bit at a time over the last 3 years. Most recent addition was the DI-2014/HDMI interconnect 2 months ago. Had this setup working now for 8 weeks. Before this, my last 2 configurations were the same as above but 1) Using Audiophilleo 2 and its Battery Powerpack and 2) Audio-GD M7 USB32 Version 1.
 
While running in the current configuration I had left the Audiophilleo 2/Powerpack in place so I can switch from that setup to the HDMI/I2S configuration using the M7 inputs selector, to then the M7 USB32 input by just moving over the Double Helix cable from the DI-2014 to the M7 USB32 input.
 
I would rate the configurations (subjectively) over two weekends of trailing as from top to bottom
 
1) DI- 2014 --> HDMI/I2S ---> M7
2) Audiphilleo 2/PowerPack ----> M7
3) M7 USB32
 
The M7 USB32 is an acceptable level of performance, but the detail, instrument placing and depth/width of spacing, just improves moving up the ladder. Initially I found the DI-2014/HDMI setup sound quite brittle but it settled down after about 3 weeks of running through on "shuttle mode' with some 'burn-in' tracks.
 
From 3) to 1) for an additional $160 + HDMI cable is a great combination at a great price IMHO (If you buy Audio-GD combo offer of M7 and Di-2014). If you already have an M7 then the Di-2014 and DIY HDMI upgrade to the M7 is a still great upgrade at around $400+
 
From 3) to 2) for an additional $900+ is not so great a deal financially
 
Any downside...perhaps. I cannot run Jplay in 'Ultrastream', have to use River, Beach or XStream. Cannot get buffers down to 'Direct' need 256, 512 and 512 for 44.1, 96, and 192. The issue there would seem to be the VIA USB32 driver used with the DI-2014 which will not work with Jplay at those lower, Optimum settings ?. But those settings working with A2/Powerpack are bested by the DI2014/HDMI combination. So perhaps sometime in the future a newer US32 driver, or changes by the Jplay team, might open up those other options in Jplay for better or worse.
 
Does make me wonder what an OR5 or the future OR6 might offer.....but for now happy listener with the DI-2014/HDMI
 
Looks like I'l be selling the A2/Powerpack
 
Frizzup
 
31/12/2014 - Tweeters on both Magnepan 3.7R's stopped working yesterday. Noticed treble fuses blown, replaced the fuses but still no treble. Doubt this relates to the DI-2014/I2S interconnect I have now been using for approx 8 weeks. Looks like I have the big job of packing these rather large speakers and freighting them back to the NZ agent. Waiting to hear back from the agent which will probably be a week away with Xmas/New Year. *&^!*^7 **** happens, but on New Years Eve ;-(

 

[drez]

  My setup is
Jplay,
Audiphils Optimizer,
Windows 2012 R2 Core,
Intel I7 Control & Audio PC's
Paul Pang Clock Upgraded ASUS Motherboards
SSD's Battery powered
Meicord Cat 7 Ethernet Cable
2 x HDPlex 100W Linear Power Supplies 12V to CPU's and 19V to motherboards
Paul Pang USB V2 USB PCIE card battery powered
Double Helix USB cable
Audio-GD DI-2014, TXCO, HDMI/I2S kit installed
Wireworld V7 Silver Starlight HDMI
Audio-GD M7, with HDMI/I2S DIY Kit replacing RJ45 input
Double Helix Balanced ACSS Cables
Audio-GD M10
Mad Scientist NEO Power Cord and Inline Purifer on the M10
Terrilium-Q Black Speaker and Jumpers about to arrive to replace current NAIM NACA5 cables
Magnepan 3.7R's
 
Assembled this equipment a bit at a time over the last 3 years. Most recent addition was the DI-2014/HDMI interconnect 2 months ago. Had this setup working now for 8 weeks. Before this, my last 2 configurations were the same as above but 1) Using Audiophilleo 2 and its Battery Powerpack and 2) Audio-GD M7 USB32 Version 1.
 
While running in the current configuration I had left the Audiophilleo 2/Powerpack in place so I can switch from that setup to the HDMI/I2S configuration using the M7 inputs selector, to then the M7 USB32 input by just moving over the Double Helix cable from the DI-2014 to the M7 USB32 input.
 
I would rate the configurations (subjectively) over two weekends of trailing as from top to bottom
 
1) DI- 2014 --> HDMI/I2S ---> M7
2) Audiphilleo 2/PowerPack ----> M7
3) M7 USB32
 
The M7 USB32 is an acceptable level of performance, but the detail, instrument placing and depth/width of spacing, just improves moving up the ladder. Initially I found the DI-2014/HDMI setup sound quite brittle but it settled down after about 3 weeks of running through on "shuttle mode' with some 'burn-in' tracks.
 
From 3) to 1) for an additional $160 + HDMI cable is a great combination at a great price IMHO
From 3) to 2) for an additional $900+ is not so great a deal financially
 
Any downside...perhaps. I cannot run Jplay in 'Ultrastream', have to use River, Beach or XStream. Cannot get buffers down to 'Direct' need 256, 512 and 512 for 44.1, 96, and 192. The issue there would seem to be the VIA USB32 driver used with the DI-2014 which will not work with Jplay at those lower, Optimum settings ?. But those settings working with A2/Powerpack are bested by the DI2014/HDMI combination. So perhaps sometime in the future a newer US32 driver, or changes by the Jplay team, might open up those other options in Jplay. For now I'm happy with this setup. Does make me wonder what an OR5 or the future OR6 might offer.....but for now happy listener with the DI-2014/HDMI
 
If you already have an M7 then the Di-2014 and DIY HDMI upgarde to the M7 is a still great upgrade at around $400+
 
Looks like I'l be selling the A2/Powerpack
 
Frizzup

That sounds promising if the $400 DI competes with the AP2/PP.  
 
How would you characterise the differences in sound between the DI/DHMI and the AP2/PP?

 

[motberg]

Hi frizzup... just a big thank you for the detailed post.. very much appreciated..

 

[Feuergeist76]

Hi Guys,

Nice reading through thie interesting findings, especially Frizzups good summary, as I'm actually also considering the M7 with or without the upgrade to the DI. Seems to be a no brainer.

How does thee M7 deal with DSD? Is it possible to simple play it via USB to the DI or will it be converted to PCM on the computer and then send to the DI? I'm pretty new the HiRes format so I'm asking this easy questions.

Cheers

Feuergeist

 

[frizzup]

That sounds promising if the $400 DI competes with the AP2/PP.  

How would you characterise the differences in sound between the DI/DHMI and the AP2/PP?

That sounds promising if the $400 DI competes with the AP2/PP.  

How would you characterise the differences in sound between the DI/DHMI and the AP2/PP?

DI-2014 through HDMI into M7 surpassed the AP2/PP through SPDIF/BNCinput to M7 in my setup in my opinion.

The differences are best expressed as 'more of the good attributes' and 'less of thd bad'. Most notable for me was the early brittleness turned into better clarity, more precision, the decaying note from a plucked string. Bass with depth and detail. Not as smooth or as sweet as A2/PP.

Ftizzup

 

[frizzup]

Hi Guys,

Nice reading through thie interesting findings, especially Frizzups good summary, as I'm actually also considering the M7 with or without the upgrade to the DI. Seems to be a no brainer.

How does thee M7 deal with DSD? Is it possible to simple play it via USB to the DI or will it be converted to PCM on the computer and then send to the DI? I'm pretty new the HiRes format so I'm asking this easy questions.

Cheers

Feuergeist

I do not think the M7 can handle DSD through any of its inputs includng HDMI. The DAC chipset was never engineered for that format. You will need to convert DSD in realtime on the PC source/streamer, i.e through J River or Foobar, or batch convert offline using something like DBconveter. M7 through USB32 or HDMI/RJ45 I2S can handle 192khz PCM. You wouldneed one of Audio-GD's ES9018 NFB Dacs to hanflr DSD natively.

frizzup

 

[ccschua]

hi frizzup
 
prior using mad scientiest neo, what was yr cable ?

 

[frizzup]

another way of looking at my conclusions is not that the DI-2014/HDMI is better than the AP2/PP just because of those devices themselves. They attach to the M7 through different input circuits/technologies BNC/SPDIF vs HDMI/I2S. The combination of the device and the input circuit/technology is what influences the result. IMHO the M7 HDMI/I2S input is far superior to its BNC/SPDIF input. What Philip/Audiphilleo achieved with the AP/PP though BNC/SPDIF was stunning 3.5 years ago when I first bought one. No insight here but maybe a AP/PP device with HDMI/I2S interconnect would out perform the DI-2014 or even the OR5/6..........

meanwhile back to the music...2L scandanvian recording at 192khz down sampled from DSD. Stunning.

frizzup