CH Precision Ethernet Streaming HD Board
It's winter time. Want to know the best tweak for the season? Humidity. Get a humidifier and maintain about 35% RH at the equipment rack. Not only does it make you feel better, it will make the equipment perform better. Sound travels through air: consider it the final wire in your system.
Ralph Pays A Visit
About a year ago, CH Precision sent around an email
introducing Ralph Sorrentino, their new Brand Ambassador for America. We struck
up an occasional telephone/email relationship. Since he was flying in for a
dealer event in September, the opportunity to meet was at hand. He booked an
By coincidence, the timing of the event overlapped with the
release of an upgrade to the CH Precision Ethernet streaming product. As we
talked about it, my interest grew. "Why not install the HD Board and I'll
do the first review?" I offered. Ralph then upped the ante by suggesting,
"While we're at it, we could also get USB streaming going." Soon the
concept for an article materialized as a comparison of three digital music
front-ends: USB, Ethernet, and the silver disc itself via my CH Precision D1
This was an ambitious game-plan and I was given a shopping list to facilitate it. We would use the Roon software app for music management because its user interface and meta data presentation are considered the best in the industry. I would need to install Roon on my MacBook Pro laptop and iPhone. Music files would be stored on a 4TB WD My Book hard drive attached to the laptop via the provided USB cable.
For the USB front-end, I reconnoitered a STEALTH Audio USB cable (MSRP $850/m) to take the bit stream to my CH C1 DAC. Music served via Ethernet required a long cable from the Internet Service Provider's router to a gigabit Ethernet switch plus two short STEALTH Black Magic Ethernet cables ($1300 one-meter length) — one going to the C1, the other to the MacBook. Everything was to be hardwired; no wireless communication. I tried to keep expenses relatively equal between USB and Ethernet, however, the transport source is exponentially more costly (maybe 10 times as much for the D1 Transport and all of its cables). Both streaming configurations followed CH Precision's recommendations to create optimized signal paths.
Ralph At Work
Implementation: The New Ethernet HD Parts
The HD Kit
We had our work cut out for us. The C1 DAC is a modular design with slots on the back to enable various options. The Control Board plug-in was unscrewed and removed (the one with the USB Firmware update jack). The new Ethernet HD board went into that slot. Then C1 and T1 firmware updates were installed. No problems—this was easy. (Step-by-step printed instructions are included with the parts. Alternately, dealers are trained to do it for you.)
Setting up the Ethernet network was also a piece of cake, but
getting Roon going for USB and Ethernet, was a bit more involved — so many
options! The Roon setup benefits from an experienced hand. If I had to do this
on my own, it would have taken a lot longer.
Bloom & Flow
The next day, ruminating about that moment, it hit me. Didn't
the same thing occur a year ago when the last CH digital upgrade was installed?
Among other things, the CH DIG IN HD replaced the three conventional digital
filters in the C1 DAC with a single new one that used a very complex, innovative
algorithm. I was caught so badly off guard that I described it as follows:
With a name like HD Upgrade, what comes to mind? High Definition, of course. I assumed it would target speed and resolution — I'd probably get more page turns and chair scrapes... But the biggest difference came from so far out in left field it made me question my ears. Instead of High Def chair scrapes, I heard more air, liquidity, and continuity.
So, now we have an Ethernet HD upgrade and it pushed the sound
in a similar direction as last year's DIG IN HD upgrade. Generally, when
manufacturers release digital upgrades you get wider dynamic range, claims for
lower noise, more speed. CH Precision releases upgrades and you get air,
liquidity, and continuity. Thus the inappropriate laughter. (Please note that I
did not have Ethernet streaming prior to this, so I couldn't do a direct
comparison with the prior iteration. I'm purely reacting to what I hear with the
Ethernet HD plug-in installed.)
Some USB Music
1) the SFS is a top notch ensemble; and
2) they produce excellent recordings of audiophile quality,
including SACDs, hi-res downloads, even LPs. Such is the case with their Beethoven: Cantata on the Death of Emperor Joseph II and Symphony No.2 (SFS
0058. I have it on SACD and a DSD 128 file).
In absolute terms, no system can do a large orchestra justice.
The roughly 90 musicians on a stage are capable of displacing a massive amount
of air. We consider ourselves lucky if it all hangs together and our miniature
doesn't fall apart. When I come home, I crank up the fourth movement Allegro
molto of the symphony via USB. Well, we needn't worry too much today. The USB
front-end delivers excellent macro dynamics with good heft and low-end grip. It
was able to grow the orchestra without signs of stress, quality was maintained
from piano thru crescendo. In addition, it had wide frequency bandwidth, good
dimensionality and accurate image placement. It was very clean and quiet; the
total absence of artifacts and distortion took me by surprise. I dare say many
CD transports would not fare as well. This was a good start as everything an
audiophile wants in playback was accounted for.
To pick a few nits, in comparison to what could be, the sound wasn't the ultimate in finesse. Textures were a little coarse, I'm not hearing the inner life and timbral shadings that give instruments their unique signature, plus the atmosphere was somewhat dry.
Roon Display Of USB Path
One of Roon's nice features is the visual it gives you of all
the processing steps for a file. For USB playback of Ben Webster's Soulville, it
tells us the input was a DSD 64 source. Roon processed the file for the Roon
Advanced Audio Transport (RAAT), followed by DSD over PCM encapsulation on the
MacBook Pro platform. The file was passed to the C1 USB streaming board, then on
to the C1 DAC, where it was upsampled to 705.6 kHz. Note that USB playback has
the benefit of the DIG IN HD upgrade (all digital inputs use it, including
Ethernet). With USB 2.0 in use, the C1 DAC can handle PCM up to 32-bit/384kHz
sampling rates and DSD up to 128 using DSD over PCM (DoP).
Some Ethernet Music
However, new complaints come forward. The enhanced flow seems
to have been accomplished in part by transient rounding and lengthened note
tails now audible as softer dynamics and less powerful macros. Part of the
coarseness with USB was due to it favoring dynamic extremes; it played either
forte or piano, neglecting the mid-level dynamic markings like mezzoforte and
mezzopiano. Ethernet brought these back and eased up the relentless low bass, so
it stopped pummeling you all the time. In actuality, dynamic range is just as
wide, but it does give the impression of less slam.
Still, there is no question Ethernet streaming advanced credibility significantly and we much preferred it.
Roon display of Ethernet Path
A look at the Roon flow chart for Ethernet shows fewer layers
of software processing performed by the computer. The DSD source file exits the
computer and RAAT was applied by the C1 Ethernet HD board. Then it passed to the
C1 DAC for conversion to ultra high density PCM. Note that CH Precision Ethernet
streaming benefits from both DIG IN HD and Ethernet HD upgrades. The C1 can
handle PCM files up to 32-bit/384kHz and DSD 256 over the Ethernet streaming
Some Silver Disc Music
Tips For Optimization
Second, the principal shortfalls (actually, where all digital
music comes up short, even the transport) is the lack of body and continuity, or
flow. That's why the last two upgrades from CH Precision gave me hope, because
they delivered on exactly those fronts. Generally, when manufacturers release
upgrades they claim lower noise, and improvements in dynamic range and speed.
Those are not the prime issues. CH Precision is the iconoclast company moving us
forward in the right direction.
Should you take the plunge at this point? My answer is a conditional YES, but only if you:
1) Can't spring for a good transport;
2) Don't want to collect CDs;
3) Want to enjoy a wide range of the latest recordings.
While we were at it, we decided to implement a few other
features, including the capability of the new board to draw less power, thus
removing the need for it to be connected to a Power over Ethernet (PoE) switch
on the network to be able to power on the C1 from the CH Control app. The board
now handles files larger than 2GB and it can play back compressed DXD files and
OGG files. We improved the compatibility ALAC file playback. All of this
results from the software re-write and increased processing power on the
Ethernet HD board.
Regarding why the new Ethernet HD board sounds better than the
USB streaming board, it could be the way each handles data errors during
transmission. With Ethernet (TCP/IP protocol), if a packet arrives corrupted it
is resent. With USB, if it arrives corrupted there is no re-send. Another reason
may be that the Ethernet HD board implemented ROON support (specifically the
Roon Advanced Audio Transport, RAAT) at the board level. With USB, RAAT is
implemented in software at the computing device level where the ROON Core is
Pricing And Manufacturer