PS Audio PWDMK2 i2s connection


#1

Hi guys, i have a PWD MK2 last version firmware, my streamer is a Raspberry pi 2 with custom linear power supply, my connection is USB, sound is ok, i could say perfect.
Thinking about an upgrade, because Raspberry share bus between USB and Lan, i bought a Audio GD i2s Output Module
link: http://www.audio-gd.com/Pro/diy/I2Skits/I2SEN.htm

I try to do the connection but PWD never take the lock. In this forum another one make this but use a PS Audio DirectStream.

Is the HDMI different between PWD MK2 and DirectStream?

my map:
PIN01 - Power 3.3V
PIN12 - BCK
PIN34 - MCK
PIN35 - WCK
PIN39 - Ground
PIN40 - Data

Could be the driver of the player?

I readed that someone use Hifiberry DAC driver with Volumio/RuneAudio player.

Thank for any help,
Arnaldo.

My custom streamer: Custom Streamer


#2

The PWD uses the I2S master clock, the DS doesn’t.


#3
Ted Smith said

The PWD uses the I2S master clock, the DS doesn’t.


Hi Ted. Thanks.

Nooooo! :-(((((

Ok, thi is the problem because Raspberry Pi 2 doesen’t generate a master clock.

You think, take out i2s from Hifiberry Digi Pro or Allo Kali Reclocker will be possible?

Thanks,

Arnaldo.


#4

If their documentation says that they are an I2S master and provide the master clock. (All of the signals have to come to the PWD. The PWD doesn’t provide master clock or bit clock.) The Allo Kali manual state that it sends the correct signals. You also have to be able to invert the Data and Left/Right signals for PS Audio products. I don’t know if inverting some signals are options on these devices.


#5

Could you explane more about it.

Thanks,

Arnaldo.


#6

The I2S connection on the PWD (and other PS Audio products) uses an HDMI cable. Each signal in HDMI is represented by a differential pair, i.e. there are two wires for the bit clock, two wires for the master clock, two wires for the data and two wires for the L/R indicator. Whenever the signal in one wire in a pair goes up the signal in the other wire goes down. In PS Audio products the data connection and the left/right connection have the wires reversed. If you are wiring your own HDMI cable you can fix this easily. If your product comes with it’s own HDMI connector you may have to invert the signals somewhere else…

If this seems too complicated you might consider using a different input on the PWD. Tho the best input can be I2S, it really depends on the source as well and if the I2S wasn’t designed well it may be easier to get a great S/PDIF or AES/EBU connection.


#7

Sorry Ted, considering that:
http://www.psaudio.com/forum/directstream-all-about-it/directstream-i2s-input/

Now PWD needs Master Clock, using this card
https://support.hifiberry.com/hc/en-us/articles/205711451-DAC-Pro-connect-external-I2S-DACs
i could have what PWD require.

What do you think about that?
Thanks,
Arnaldo.


#8

Indeed the signals you need are there. You’ll need the pinout for the HDMI cable and differential LVDS drivers. If you haven’t discovered http://www.i2s.sonore.us you’ll be happy. The HDMI page has most of the details you’ll need.


#9

Thanks Ted for this informations!

Arnaldo.


#10

UPDATE:
i bought hifiberry digi + pro, i have soldered 5 pins on the i2s out of this card named P4.
i made this map:
1 GND
2 Master clock (22.5792MHz for 44.1, 88.2, 176.4 kHz sample rates, 24.576MHz for 48,96,192kHz sample rates)
3 Bit clock (frequency = 32/64* sample rate)
4 Frame clock (frequency = sample rate)
5 Data

5 -> DATA
3 -> BCLK
4 -> WCK
2 -> MCLK
1 -> GND

from hifiberry digi + pro to audio gd output module

hifiberry digi + pro:
https://support.hifiberry.com/hc/en-us/ … l-I2S-DACs

audio gd output module
http://www.audio-gd.com/Pro/diy/I2Skits/I2SEN.htm

DOES NOT WORK!!
:( :( :( :( :( :( :( :(

Any idea?

Thanks!

Arnaldo.


#11

Without having the devices people are buying in front of me I can’t really guess where people might be making mistakes, and further I can’t warrant that any given device is well designed or PS Audio compatible from just the amount of info on the typical web sites.

In this case we’re talking about products that I don’t have, didn’t design and have never used. I’ve answered technical questions with correct technical answers, but I have to draw the line somewhere.

Further, as I’ve said in the past, I suspect that people can get just as good sound quality with, say AES/EBU or S/PDIF (or even TOSLink) as I2S if grounding, etc. isn’t done well. The advantage of those is that they are standardized and directly supported by most hardware so the risk is quite a bit lower.


#12

Hi Ted!

What do you think about this card? Could be great for me?

https://www.audiophonics.fr/en/diy-interfaces/asynchronous-sample-rate-converter-module-cs8421-32bit192khz-p-11456.html

Thanks,

Arnaldo.


#13

First off it won’t work with the DS, DS Jr nor, I suspect, with the PWD and other PS Audio DACs. I changes all input sample rates to 211kHz which isn’t supported in the DS firmware.

ASRC (asynchronous sample rate conversion) is a whole different kettle of fish - it’s not for me - it may have lower output jitter than input jitter, but it encodes the input jitter as changes in the digital bit stream, thereby making it impossible to remove that input jitter down stream. Whether any given DAC sounds better with ASRC than SSRC is up to the design of that DAC, the rest of the system it’s in and the ears of the listener.