Audio-Gd Master 7 - Discrete Fully Balanced DAC (PCM1704)
May 18, 2014 at 7:46 AM Post #1,712 of 4,463
Is it linear ??? If it's switched it's no good to use .
Al
 
May 18, 2014 at 8:36 AM Post #1,713 of 4,463
http://ppaproduct.blogspot.tw/2014/01/linear-dc-adapter-for-battery-supply.html
http://ppaproduct.blogspot.tw/2013/07/audio-grade-usb-30-pcie-card.html

The above links are the battery trey and the PCI express usb card
Al

 
  http://www.audiocircle.com/index.php?topic=122520.0
 
I just bought a ppa card myself, because it's easier to chase the small gains first and hit the off ramp later. Don't have it yet, but this thread is pretty interesting.


Interesting.... Let us know how it goes.. 
 
May 18, 2014 at 8:49 AM Post #1,714 of 4,463
Is it linear ??? If it's switched it's no good to use .
Al

It's a linear 5v 2 amp ac to dc converter. Anything that can do 5v in the 1 to 3 amp range will work. Not sure if it was that same thread on audiocircle, but one guy measured the output from a acopian and said it was rock solid. That, and most can be found on ebay for less than $30, cheaper if you search around. (Grabbed mine for $26ish). 
 
(edit: If you google Acopian 5EB200, the 5 is the voltage and the number after EB is the amps, in this case 2. Other useful models are the Acopian 5EB100 and Acopian 5EB150, 1 amp and 1.5 amps respectively. The Acopian 5EB100 would work just fine, but I was having trouble finding any cheaper than the Acopian 5EB200 I ended up buying.)
 
May 18, 2014 at 8:49 AM Post #1,715 of 4,463
I am going to remove the hdmi today
To put back the USB and compare the USB to rj45
Offramp. Both with the new PPA USB card
Al
 
May 18, 2014 at 8:51 AM Post #1,716 of 4,463
Aha I'll shall buy one then they are really cheap
Nice find thanks
Al
 
May 18, 2014 at 8:39 PM Post #1,718 of 4,463
Ok this is easy but sad. The offramp beats all inputs compared to the USB without it. It painfully obvious.
Now using the USB with the PPA card meaning using the USB on other board it is even worse . So the card does work some magic . No with the card and the offramp this is a really PCM dac.
Test was done with social club at 24/96 and senn hd800 headphones with the hdvd800 as amp only. So empirical is still the champ here. Hey dac ladder guess whAt I have no rj45 output on the offramp . Want to guess why hahahah.
Anyway it's going back to empirical as soon as he gets the USB output option going.
This dac is a really good PCM dac .
Now it beats the mytek easy and the hdvd800 dac inside as well.
But the new direct stream beats them all agin just testing with PCM.
As to the why it's better with the offramp . For starters clIrty it's just better all around , but it improves the seperation of the music so voices are more seperate when all are signing together .
Forgot to add this. The HDMI is the best input way above the USB and it beats out the AES with the offramp as well .
Al
 
May 19, 2014 at 10:54 AM Post #1,719 of 4,463
.Hey dac ladder guess whAt I have no rj45 output on the offramp . Want to guess why hahahah.
Al

Sorry to hear that and yes be careful with connecting the Off Ramp.  I received the Short Block last week and it did not work.   The PC USB port did not see the Off Ramp.   With Off Ramp Dynamo power supply disconnected from AC the Off Ramp three LEDs glowed dimly so not sure what is going on there since the PC +5V is supposed to be isolated with the Short Block.  So I disconnected the Short Block and not sure I want to risk again blowing up my equipment.   The HDMI I2S GNDs are directly connected between the M7 and Off Ramp in the same way as they are with RJ45 I2S.  The Off Ramp really does not like this GND reference removed or connected with power on.  You get large voltage spikes doing so.   The Short Block documentation has a stern warning about powering all equipment from the same AC outlet.  Steve also gave me a verbal warning on my last communication with him.
 
So take notice with connecting the Off Ramp (any I/O port).  If there is one thing to ding the box on that would be it.   Steve fixed my Off Ramp for no charge though.  But hot plugging the HDMI cable took out seven ICs and the Hynes I2S regulator.  Also blew up the chip on the HDMI I2S board.  I did not have the M7 connected at the time (thank goodness).  So proceed with caution with the separate USB board and power supplies.  I can't stress this enough.
 
May 20, 2014 at 5:53 AM Post #1,720 of 4,463
Good morning
I have been in contact with Steve regarding the the rj45 problem. . It's not the audio gd as if I use both PC board inputs with the USB it works fine. Also the HDMI works fine.
Now Steve says if the HDMI works the rj45 does. This leaves me to think the cable is damaged. When I test the cable with a data tester it shows only two pairs have continuity and one pair is shorted to another pair. . If I try a regular data patch cable it does not work and gives me a whinnying sound. So dacladder do you have the pinout for a cable . I will make my own to try out . If it works Steve will have the cable repaired . Steve says the cable should have 4 pairs being used ,so it seems the cable is bad . And making my own cable and having it work will prove this.
Al
 
May 20, 2014 at 9:10 AM Post #1,721 of 4,463
Good morning
I have been in contact with Steve regarding the the rj45 problem. . It's not the audio gd as if I use both PC board inputs with the USB it works fine. Also the HDMI works fine.
Now Steve says if the HDMI works the rj45 does. This leaves me to think the cable is damaged. When I test the cable with a data tester it shows only two pairs have continuity and one pair is shorted to another pair. . If I try a regular data patch cable it does not work and gives me a whinnying sound. So dacladder do you have the pinout for a cable . I will make my own to try out . If it works Steve will have the cable repaired . Steve says the cable should have 4 pairs being used ,so it seems the cable is bad . And making my own cable and having it work will prove this.
Al


Well that is good news but not for the expensive RJ45 cable perhaps.   All four I2S signals are used.  The pinout on the Master 7 side requires the OR5 SCLK signal to move from 1st pair to 3rd pair and SDATA and L/RCLK signals to move up a pair position each (2->1 and 3->2).  MCLK stays at position 4 on each side.
 
Off Ramp RJ45 I2S Output
 Pin 1 - SCLK
 Pin 3 - SDATA
 Pin 5 - L/RCLK
 Pin 7 - MCLK
 Pin 2,4,6,8 GND returns
 
Master 7 RJ45 I2S Input
 Pin 1 : SDATA
 Pin 3 : L/RCLK
 Pin 5 : SCLK
 Pin 7 : MCLK
 Pin 2,4,6,8 GND returns
 
May 21, 2014 at 9:01 PM Post #1,725 of 4,463
Try the dac without the internal amp. And post results
Al
 

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