HFAS1 Developer Interview
Focus on fidata peripheral devices
We asked audio critic Hajime Sakaki to interview the developers of the HFAS1 for this article,
which explores some of the challenges they faced during the development process.
Hajime Sakaki, audio critic
Interviewer
Hajime Sakaki,
audio critic
Mr. Sakaki is active as a commentator who addresses a variety of audio devices,
making his views available in audiophile magazines, online, and at audio and
visual events.He has given trial listening presentations showcasing fidata at numerous
tradeshows and exhibitions, and for this article, we asked him to interview the
fidata development team.
Planning: Yasunori Kitamura
Hardware design: Akiya Miyamoto
Software design: Yuji Minagawa
fidata Music App design: Ryusuke Tanigawa
Planning: Yasunori Kitamura
Kitamura:
fidata is an audio brand with an uncompromising commitment to the digital
domain. As suggested by the expression “Hi-Res.grade Network Audio
Components,” our intention from the beginning was to roll out various
products, rather than limiting ourselves to a server.
Initially, we worked on a server, which is a core competence for I-O Data.
Then we planned to bring the fidata focus on quality to a network player,
USB DAC, and connectivity.
Kitamura:
We set about developing a LAN cable first because as we visited stores
after launching the server, we occasionally received feedback that the
system's sound quality varied with the LAN cable being used, and because
such a cable was necessary in order to use the server.
fidata audio LAN cable:HFLC
Planning: Yasunori Kitamura/fidata audio LAN cable:HFLC
Planning: Yasunori Kitamura
Kitamura:
We didn’t set out in the usual manner with any preconceived ideas about
the price point. Instead, we pursued a level of quality that we found
acceptable, and then the cost of materials led us to settle on this price.
Miyamoto:
We focused on taking into account the various parts and components
that make up the product, of course, and also on bringing them together
to create the finished product. For example, the HFLC uses a Cat 7
cable, but the shielding is cut at one of the connectors so that the
connected devices’ grounds are not connected.
Since sound quality is significantly affected by whether the shielding is
cut or not, we decided to cut it, based on the assumption that the cable
would be used with the fidata server.
Controlling the amount of noise that would be conveyed by the cable
was a major focus in our development work, and we very carefully
studied how to accomplish that goal, including through listening tests.
The HFLC uses silver-plated OFC conductors, and that decision was the
result of listening tests, rather than any sort of desire to gain the
“sound of silver plating.” In addition to sound quality and structural
considerations, we focused on the cable’s flexibility, so that an excessive
load would not be placed on connectors.
Hardware design: Akiya Miyamoto
Mechanism for reducing noise with a cut in the shielding
Hardware design: Akiya Miyamoto/gold-plated connectors from Telegaertner.
Miyamoto:
The Telegaertner connectors were not among those we were considering at first as we carried out listening tests to compare the various
alternatives, including products from Telegaertner as well as from other manufacturers, gold-plated connectors, and normal connectors.
As the result of that process, we determined that the gold-plated connectors from Telegaertner delivered the sound quality best suited to
fidata while listening to music being played through them. Other advantages of the Telegaertner connectors included a design that allows
stable contact with signal lines while providing a good fit with the positioning of the signal lines from other cables we had already chosen.
Planning: Yasunori Kitamura
Kitamura:
We can confidently recommend using the HFLC LAN cable to connect a fidata
server to a network player.
Since the cable is designed to aggressively control noise when connected to a
server as described above, that combination is the best choice for customers.
Although it’s been designed to connect a server to a network player,
it can also be used to connect a server to a network (hub).
○Note from Mr. Sakaki:
In my own audio system, I use the HFLC-1.5M to connect an HFAS1-XS20 fidata
server directly to a SFORZATO DSP-Dorado network player using the shortest
possible cable.
Seeing as how the HFLC was developed specifically for use with fidata, I feel
that its biggest advantage lies in improved S/N performance and increased data
capacity.
Some servers lack the dual LAN ports provided by fidata, in which case it’s not
possible to connect the server directly to the network player.
In such installations, using HFLC for the hub and network player connections can
be expected to yield the greatest advantages.
Hajime Sakaki, audio critic
Planning: Yasunori Kitamura
fidata audio USB cable:HFU2
Kitamura:
As with the LAN cable, we prioritized controlling noise. Most
general-purpose USB cables have resin-molded connectors,
but in our pursuit of ideal performance, we fabricated our own
machined aluminum connectors. This decision was taken to
limit vibration by ensuring the connectors could support their
own weight and to provide stable contact. Additionally,
the connectors incorporate a slit to prevent formation of a noise
loop.
Miyamoto:
First off, the USB specification does not allow shielding to be cut,
so we had to take a variety of creative steps to address that.
The slit in the connector is one of those steps. We also focused on
internal connections and on bonding with the caps.
With regard to cable structure and wire choices, we repeatedly cut
and tried different configurations, as with the HFLC.
Hardware design: Akiya Miyamoto
Mechanism for reducing noise with a connector slit
Minagawa:
The first thing we focused on in developing the software was the
time it takes to launch it. Whereas a NAS generally remains powered
on all the time, audio devices are turned on when the customer wants
to listen to music and then turned off afterwards. As a result,
we worked to accommodate that method of use.
fidata software
Software design: Yuji Minagawa
Comparison of fidata launch time with an I-O Data conventional NAS
Our fundamental goal with fidata is that customers be able to use it
as soon as they connect it. To that end, we sought to make the
settings screen simple and intuitive, so that customers could
understand it without needing to consult the user’s manual.
In addition to delivering the same usability on computers,
smartphones, and tablets, we've provided a settings guide in the
app (fidata Music App).
Minagawa:
When we were developing fidata, Twonky Server was the de facto standard in server software for network audio.
Although there were alternative packages available, we chose Twonky Server because we felt it would best allow fidata to be sold worldwide.
We customized the sort order for Twonky Server’s navigation tree (used to select tracks) by soliciting feedback from stores and
through conversations with the product planning team.
Twonkey
Software design: Yuji Minagawa
Software design: Yuji Minagawa
Minagawa:
We gave top priority to functionality that a playback device is required
to deliver, for example gapless playback. fidata’s playback function
supports OpenHome, and that support has earned praise from a
usability standpoint.
That said, different OpenHome implementations exhibit slight
differences, and it was a challenge during the development process to
ensure that fidata could absorb those differences. Additionally,
the product has to play a sound source while simultaneously
functioning as a server, so allocating resources in terms of processing
capacity was a major issue. Thanks to optimization of that aspect of
product, it’s now possible to play high-rate DSD sound sources.
Apart from this sort of fine-grained software development,
we continue to work to make improvements, for example by having
the team verify connectivity for various USB DACs.
Minagawa:
The mechanisms by which Diretta operates have been complete for some time,
but this was the first attempt in the industry to embed it in a Linux-based NAS.
As an example of the challenges posed by that effort, Diretta initially did not
anticipate devices such as the fidata server that have two LAN ports.
We worked closely with Diretta’s developer and resolved one problem at a time,
until we were able to offer Diretta support.
fidata-Diretta
Software design: Yuji Minagawa
fidata Music App
Tanigawa:
Previous network audio control apps often felt difficult to use, so we
identified what was good about them and focused on the interface and user
experience.
Additionally, after putting in place structures to pursue usability and
develop the app, we worked to incorporate feedback from peripheral
device manufacturers.
fidata Music App design: Ryusuke Tanigawa
fidata Music App design: Ryusuke Tanigawa
Tanigawa:
DMR (DLNA player) support was particularly challenging. DLNA comprises
a series of guidelines designed to make possible a minimum level of
interconnectivity, but it does not provide clear specifications concerning
detailed operation. As a result, a lot of labor-intensive adjustment work is
necessary in order to ensure the app will operate properly when used in
combination with network players from other manufacturers.
As the official app, you might say that there was no need to focus on
ensuring fidata Music App works with products from other companies.
However, we took an active approach to doing just that because we want to
raise the overall bar for the network audio experience through the fidata
brand. In that sense, any specific information we can obtain about using the
app with products from other companies leads to improvements to the app.
In the end, we're happy if customers using the app become fidata
enthusiasts.
Hajime Sakaki, audio critic