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Audio-Gd Master 7 - Discrete Fully Balanced DAC (PCM1704) - Page 83

post #1231 of 3496
Here is what I know and you can go to there forum and pose your question and you will get the detLed info you wish. But here is a simple answer, the offramp has several outputs that are all on all the time. So each output is setup to work with the different output setups. . So according to Steve n the maker of the offramp said it's different as well. No how it is different I do not know.

Al
post #1232 of 3496

Ah.  So the OR5 product is versatile in that it offers multiple I2S protocol outputs, HDMI and RJ45 being two...

post #1233 of 3496
post #1234 of 3496
Quote:
Originally Posted by purrin View Post

Anyone know what Metrum uses? I hate it when manufacturers scratch out the lettering on the chips. Really cheesy.

 

Not certain but from fairly intensive study of the pinout and various numbers that Metrum quote (like slew rate) it looks a dead ringer for TI's DAC8580 (with the internal digital filter turned off).

 

@DACladder - that ARDA DAC chip is vapourware for sure. As far as I'm aware though they're still making their ADC, which is used by Ayre (amongst others).


Edited by Sapientiam - 1/24/14 at 4:59pm
post #1235 of 3496

Thanks, Al.  I'll probably follow up with DACLadder.

post #1236 of 3496
Quote:
 Ah.  So the OR5 product is versatile in that it offers multiple I2S protocol outputs, HDMI and RJ45 being two..

Yes, the same four I2S signals on two different outputs - RJ45 are single ended LVTTL and LVDS (low voltage differential signalling) using an HDMI connector.  The HDMI connector signals are not the same protocol as what connects from a Blu-Ray player to television.  Companies are just using the HDMI connector and transmit/ receiver chipsets to move I2S data/ clocks down a standard HDMI 1.3 type cable. Should be superior to LVTTL signals on a CAT cable.

 

Quote:
 DACladder - that ARDA DAC chip is vapourware for sure. As far as I'm aware though they're still making their ADC, which is used by Ayre (amongst others).

I was afraid of that.  Looked like an advanced datasheet.   Ardatech is (or was) in Mt. View, CA and down the road from where I work.  I wrote them asking for more information using my company Email which may get a faster response.   Maybe (or maybe not) hear back next week.  


Edited by DACLadder - 1/24/14 at 5:38pm
post #1237 of 3496

Yes, I'm just wondering if there's a path forward for the PWT balanced I2S output using the HDMI connector/cable and the rather simplistic (SE?) M7 I2S input using the RJ45 connector/cable.  Obviously Empirical Audio has found some way to make the I2S output signals compatible internally. Can the PWT I2S LVDS signal line outs be somehow converted M7 LVTT  input signals via some sort of converter board similar to what the OR5 is doing?

 

I have a copy of the PWT I2S HDMI pinout assignments for comparison with the M7 pinouts if you're interested.


Edited by jacal01 - 1/24/14 at 5:53pm
post #1238 of 3496
Quote:
Originally Posted by jacal01 View Post
 

Yes, I'm just wondering if there's a path forward for the PWT balanced I2S output using the HDMI connector/cable and the rather simplistic (SE?) M7 I2S input using the RJ45 connector/cable.  Obviously Empirical Audio has found some way to make the I2S output signals compatible internally. Can the PWT I2S LVDS signal line outs be somehow converted M7 LVTT  input signals via some sort of converter board similar to what the OR5 is doing?

 

I have a copy of the PWT I2S HDMI pinout assignments for comparison with the M7 pinouts if you're interested.

As annoying and effortless as it sounds, I'm pretty sure the honest answer is 'no'. Don't look at it as if I2s is some standardized format that is just being sent via one termination or another and that should be easily switchable, look at simply as a term; and one that in this case means different things from different companies. And Empirical Audio can do it because they're a manufacturer and they have the source signal from their custom made gear to work with, serious expertise, thousands of dollars, and their own company which specializes in digital audio. I'm not sure who you are, but I don't have those resources available for my DIY audio hobby.

 

I recently got the pin-out from the PWD Mkii HDMI-I2s from PS Audio because I was looking at making up my own LVDS->HDMI I2s cable to feed from an Audio-gd DI-V3 I2s output to my PWD Mkii HDMI-I2s input. I don't know much about the format, but as soon as I saw what was going on I gave up on the idea. 

 

For me, it's back to trying to find a USB-> HDMI I2s convertor that doesn't cost more than my DAC... Damn pricey OR5... And although I know the OR6 is going to be in the same bracket, does anyone have any info on it yet? Now that Steve is moving away from the HiFace chipset I'm interested to hear some reviews. Especially since it'll be able to do Integer Mode now :-D  That was one thing I really didn't like about it before, and also that USB->XXX convertors that could were said to approach the OR5 with Integer Mode enabled. Now with a levelled playing field the OR6 should be a show stopper?

post #1239 of 3496
This all makes sense but I did not wait as I wanted to hear the improvement
And I spent about 2800 with all the options cables and psu
But any DAC I use it with moves up several steps
And using the offramp with my UM PP6
Or the JH audio JH3a / 16 fp is just sureal
In sound. As to where and when the offramp 6 comes out
The truth is I did not think it can improve the dacs we connect to it
As such it's a end game now with the offramp5.
I have an msb stack all in and that DAC without the offramp is just amaising.
So I do not think there is much or any to more to have
With improving the offramp.

Al
post #1240 of 3496
Quote:
 I have a copy of the PWT I2S HDMI pinout assignments for comparison with the M7 pinouts if you're interested.

Send me the PWT I2S pinouts and I will compare with the OR5.  PM me here and I'll forward you an Email address.

 

One of the reasons I purchased the Master 7 is that it has an I2S interface.  Good way to guard against rapidly advancing I/O standards I thought.   But there is no standard for I2S and I had a hard time getting the OR5 and Master 7 to sound consistently over the RJ45 port.  One day excellent and the next OK.  You can read about my trials and efforts in this Master 7 section starting in the mid/ late 60s pages.

Quote:
 Can the PWT I2S LVDS signal line outs be somehow converted M7 LVTT input signals via some sort of converter board similar to what the OR5 is doing?

Look at post#1056.  I started a design to replace the Master 7 RJ45 board with a version that utilizes the OR5 HDMI.  Just requires a single IC chip to convert LVDS to TTL.   The new board will connect to the current I2S header on the M7 DSP board.   Unfortunately I had some bad luck and blew up the OR5 I2S interface.  I was one day away from trying it out in the Master 7.  So the project is on hold until the OR5 is repaired.   If I ever get it working I will post in this forum. 

 

I won't be offering upgrade kits for others to try.  A lot of bad things could go wrong.  The current adapter board needs a tweak to get the HDMI pin spacing correct.  They are a little too narrow right now but I made it work for my testing.  The adapter needs +3.3V from somewhere in the M7 to power the LVDS receiver chip.  I have a good idea where I'm going to get it but haven't yet gotten that far.  And there is the mechanical issues of will the board fit and mount exactly like the current RJ45 board.  Also the parts I used on the design are small.  I had to use a binocular microscope to assemble a couple of boards for testing.  So I'm not going to spin the board design for my needs (if ever) until it is proven to work.

 

But I will share all information if someone else wants to run with it.  For starters there is a schematic and a prototype PCB (rev 2).  One chip with HDMI coming in on the left and LVTTL going out on the right.  Steve at Empirical Audio gave it a thumbs up.  He wanted to know what was connected when the OR5 blew. If I were to change any of the circuits I would probably want to power the LVDS chip from a linear regulator (LDO) for better power supply isolation/ rejection.  But that is another day and many more dollars to develop.  But in low production quantities you could build the board with all the parts for about $20 or less.

 

Edit: keepandshare is up.  You can get the schematic here.

http://www.keepandshare.com/doc/6797612/hdmi-i2s2lvtl-rev2-0-pdf-45k?da=y

 

Edit:  Here is Rev 2 of the HDMI 2 LVTLL adapter used in testing.  Looks big but about the same size as the current M7 RJ45 board.

 


Edited by DACLadder - 1/25/14 at 5:11pm
post #1241 of 3496
Thanks for the posts and you efforts. It has made me enjoy mine all the more. Over the weekend I will swap boards and see if I can hear a change.

Al
post #1242 of 3496
Quote:
 Thanks for the posts and you efforts. It has made me enjoy mine all the more. Over the weekend I will swap boards and see if I can hear a change

Excellent!  Al is referring to an RJ45 board swap with 75 ohm resistors for termination instead of the supplied 220 ohm termination.   Just swap the board with two screws and connect the header to the M7 DSP board?   How much did Kingwa charge for this board?   

post #1243 of 3496
30.00. Used. With shipping and he gave me two ribbons with it one terminated with jacks on both sides and one with a termination on one side . If I needed to solder directly.

Al
post #1244 of 3496
Quote:
I have a copy of the PWT I2S HDMI pinout assignments for comparison with the M7 pinouts if you're interested.

I didn't make the PS Audio/ PWT connection at first but yes it should work OK.   The OR5 HDMI was designed around the PS Audio and Wyred4Sound equipment. 

 

But send the pinouts and will double check...

post #1245 of 3496

Hi folks!!! I got it! It was the cable I think....using a VOVOX aes I can play all sample rates perfecly at mininum latency!.....Thank you all for your support!

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