For those who have
never heard of the "Pink Faun I2S Audio Bridge"
before;
Here is the link of my
earlier 2015 review:
Link:
http://modelpromo.nl/PinkFaun_I2S_Bridge.htm
This article is about the question:
What is the best way to
connect my DAC to my self-built audio PC?
To get an answer to this question you must first know how your DAC is
S/PDIF (coax/optical digital)
S/PDIF
is an already outdated way to transport digital audio files.
The maximum PCM resolution
S/PDIF can
transport is
32bit / 192 kHz.
Therefore
it's not suitable for the newer and larger DSD, DXD audio files.
This
connection still can be found on many
older, but also newer DACs.
Although
S/PDIF
is
dated; this does not alter the fact that S/PDIF
can't
sound very
good!
There are very good sounding S/PDIF
DACs for sale, such as the
"Tentlabs b-DAC mkII" that sounds
much better than many other USB DACs.
USB
Most
DACs that are currently available have an
USB connection to which the DAC can be connected.
This can be: a
streaming device, amplifier, or DIY audio PC.
USB is popular because
it is cheap, versatile and can also transport the newer and large DSD,
DXD and PCM audio files.
But the disadvantage is that
most
USB
DACs do not sound really musical.
Often
the
music
sounds a bit unreal, too dynamic, tiresome
or
not organic.
This is because USB DAC chips (eg: ESS) are
not only very cheap, but also very integrated
This is especially easy for the manufacturer,
he doesn't have to do anything else but place the chip in a housing, and
the product is ready.
As a result, the margin (profit for the
manufacturer) is high, but the quality for the consumer is low.
It is therefore better to invest in a DAC
with a better (more expensive) DAC chip such as "Burr Brown" or a good
ladder DAC (R2R) such as the open source community DAC called: "DSС2 v2"
Example: In my
Audio-gd Master 7 DAC there are no less than 8 (!)
Burr Brown DAC chips of the type: PCM1704UK
These now cost around $ 70 each.
My DAC already has a cost of $ 560 in DAC
chips alone ...
Quality costs money, but never pay too much
for a DAC.
An
expensive DAC containing an ESS chip is a waste of money! you can do
better on Aliexpress
buy an ESS DAC for around 200 euros, and that
probably sounds even better :-)
But the cheap
and low quality DAC chip is not the only reason USB DAC's sound not so
good
It's
also
because
of the fact that USB was
never
designed for transporting High Definition audio.
There is no
official standard for transporting High Resolution audio over USB.
In order to get
this done, the manufacturers themselves have developed
their own protocols and other ways to
ensure that High Resolution audio files still can
be transported over USB.
So every manufacturer has his own "technique" or "trick" to do this...
The problem is to transport digital audio over USB a lot of conversions steps have to bre made
Also a
special interface chip has to be used to
converted
the music data
over USB like the "Amanero"
or "XMOS"
module.
In addition, the data must be converted into a protocol developed by the
manufacturer itself.
Again because USB does not have this
functionality of its own.
So with all these conversions
it's understandable that things can go wrong...
That does not mean that there are
not
also
good sounding USB DAC's
available
but they are rare.
I have good experiences with the "Amanero Cobo384 module"
This module
is used by many manufacturers and has very good specs.
As you can see in the above diagram:
USB was never
been designed for transporting high-resolution audio, there is not
even special master clock
signal!
I2S
i2S = a serial link especially designed for
digital audio
The serial bus has only to handle audio
data, while the other signals, such
as sub-coding and control, are
transferred separately.
To minimize the number of pins required and
to keep wiring simple, a 3-line serial
bus is used consisting of a
line for two time-multiplexed data
channels, a word select line and a
clock line.
- serial data (SD)
- word select (WS)
-
continuous serial clock (SCK)
Therefore I2S can be implemented in
many different ways:
Over multiple BNC, RCA connectors or even over a
single HDMI cable:
“ I²S” HDMI pinout
(Audio-gd)
Note:
While the I2S is a official protocol
especially designed for digital audio,
there is no official way to connect two digital devices together.
Therefore every audio manufacturer has his own specific "I2S"
implementation.
Above is the “I2S” implementation of “I2S” over HDMI
of the brand "Audio-gd"
Pink Faun also has choosen for HDMI to transport I2S signals
Ethernet (RJ45) – I2S DAC
There is
also a fourth way to connect a DAC, namely directly via the Ethernet
network (RJ45)
For this you need a special DAC (often called "endpoint" or "bridge")
This DAC has an
Gigabyte
Ethernet connection
(RJ45) and
the DAC sets the audio data internally
immediately into I2S, so that
the signal can be processed internally.
So there is no USB involved.
Please note:
This is not quite the same as a DAC with an "I2S -
RJ45" connection.
Because for these types of DACs you still have a
special "I2S - RJ45 Bridge card" and an audio PC to convert the audio
signal to I2S over Ethernet (RJ45)
What I'm talking about now is a
"special" DAC (or endpoint) that is directly connected to the Ethernet
network.
You don't need an audio PC again for these I2S DACs!
No USB cables, and no special “I2S Bridge PCI-E card.
You can
easily connect these “Ethernet I2S DACs” to the existing network in any
room where you want to hear music.
The "HiFi Berry DAC + XLR" is a
good example of an "I2S DAC" directly on
the network can be
connected. It is actually an Audio PC + Bridge + DAC in one!
Which connection should I choose now?
Afbeelding van een “SPDIF Optical and RCA
Out Plate Cable Bracket” te koop op Aliexpress
voor onder de 10 euro
https://www.aliexpress.com/item/32810954369.html
i2S
I2S: a serial link especially designed for
digital audio.
The serial bus has only to handle audio data,
while the other signals, such
as sub-coding and control, are
transferred separately.
To minimize the number of pins required and
to keep wiring simple, a 3-line serial
bus is used consisting of a
line for two time-multiplexed data
channels, a word select line and a
clock line.
- serial data (SD)
- word select (WS)
-
continuous serial clock (SCK)
If you have a DAC that has an "I2S" input connection, then you can choose to use
Innovations:
The Pink Faun I2S
Audio Bridge has been given a modular design where
the manufacturer maintains a database of all
manufacturers that make an I2S DAC
Pink Faun therefore knows exactly what the
relevant I2S HDMI pin layout is
of every DAC.
When ordering the Pink Faun I2S Audio Bridge
you must first select your I2S DAC
after which Pink Faun ensures the correct
configuration.
This way you are assured that the card will
work perfectly with your DAC
Another important innovation is the ability
to easily upgrade the standard TCXO clock.
For audio streaming with I2S, the I2S card in
the audio PC determines the tempo
That is why it is important that the "clock"
on the I2S card is very precise.
The standard clock gives excellent results
according to Pink Faun
But if you want to experiment with other
(more precise, better) TCXO clocks
then this was now possible.
Pink Faun has created a very simple upgrade
system with its HEA bridge system for upgrading the TCXO clock.
The clock upgrade consists of a separate
board that is very easy to install on the HEA bridge (without soldering
or programming)
This clock upgrade can also take place at a
later stage, for which no technical knowledge is required.
The clock upgrade is easy to install and the HEA
bridge automatically switches to the improved clock.
I chose this review to first review the standard
version, because I first want to know what that sounds like.
Installing the card
After ordering the Pink Faun I2S Audio Bridge, the card was received
in an anti-static bag in a sturdy box.
Without any manual or drivers.
What I'm already used to as an IT professional when, for example, I
order a PCI-E card.
But when inquiring with the supplier this turned
out to be normal, the card would not need any drivers by default.
I
did receive a download location from the supplier via email where I
could download an optional "driver", with which you can stream using
"kernel streaming"
In the first instance I will not do this for a
while, I will first go to the Pink Faun I2S Audio Bridge
configure by
default and listen how this will sound.
But no installation manual
... or any other info ...
The card apparently still needs to be fed
extra with the Molex connector to your power supply
or even better to an external linear power
supply
After reading the
“installation manual” it appears that the Molex power supply connection
is also used for the operation of the card.
The card can be powered in two ways:
1) via the power supply of the PC (via the
Molex connection),
2) or via an external linear power supply
through the 5.5 / 2.5mm center positive DC jack connection on the rear
side.
There is
no technical specs mentioned of the card in the "installation manual"
which is a shame.
Because I don't know how much power (Ampere)
the card needs to function properly, this would be nice to know if I
wanted to feed the card via a battery.
Because I will first test the card as standard, I use the "Molex" connection.