Over the last couple years I've talked to Jonathan and Aaron of Halide Design via email numerous times. Half of our conversations were about Halide Design products while the other half were about computer audio and the high end industry. After every conversation I always said to myself, "These guys are really cool, really smart, and have great potential in high end audio." There's a lot to like about the unjaded enthusiasm and ideals of Jonathan and Aaron. Never once have they talked about high margins and snake oil. It's really refreshing to hear their ideas about new high quality products at relatively reasonable prices. These guys are not in the business to separate people form their money. Jonathan and Aaron really have a passion for creating great sounding and innovative audio products.
Jonathan and Aaron share many beliefs with the readers of Computer Audiophile. "Computer audio is here to stay, and at this point, can supply sound quality that matches or rivals the best audio devices out there. Computers can store all your music (lossless of course) and have moved from a novelty, to a convenience, to a central component of high resolution computer playback." Said Jonathan and Aaron.
When Jonathan and Aaron first dipped their toes into designing commercial high end audio components, the company name Devilsound Labs seemed perfectly fine. At least it signified something different from the more traditional audio companies. According to Jonathan, "We wanted to make something for the "new generation" of audiophiles. Simple, small, easy to use, and relatively inexpensive. Thus was born the Devilsound DAC, our first product. The idea there was to take ideas that had been floating around in the audiophile world, such as non-oversampling on the D/A converter and high-quality interconnects, and add our own touches."
The signature touches of Devilsound Labs products are good components, circuit design and layout, and compact size without sacrifice. In almost every audiophile endeavor shorter is better at keeping the audio path cleaner. During the design phase no opportunity is missed to make these paths shorter in the interest of better measurements and increased sonic accuracy.
After the successful Devilsound DAC and a bit more experience under their belts Jonathan and Aaron decided to advance the company further with a new name and new product. They settled on Halide Design as the label to launch new products. It does sound much more professional and robust compared to the possibly juvenile Devilsound Labs.
Continuing with their signature design touches Jonathan and Aaron set out to make The Bridge USB to S/PDIF converter. They saw no need for the traditional S/PDIF output cable. Instead they aimed to clean the signal path by using what they call an "Active Interconnect" where the device is really a signal unit. "The advantage of eliminating unnecessary components is that it leads to reducing other unnecessary components. So for instance, since we don't need any sample rate converter or other bulky devices to clean up jitter, this saves board space, and makes it possible to build the device small enough to eliminate the cable as well." Said Jonathan.
Short clean signal paths are not the only innovative design elements in The Bridge. Without a separate power supply The Bridge receives power via a USB port. Five volt power emanating from the less than satisfactory switching power supply of a computer is the last thing an audiophile wants feeding his components. To the layman it may appear there is no room in The Bridge's small CNC milled anodized aluminum frame to address this dirty power issue. Audiophiles are used to enormous linear power supplies, exotic power cords, and numerous power related products. I'm certainly guilty of running a separate power sub-panel to my listening room with dedicated circuits for the components. All of this seems so far from what is possible in the tiny Bridge USB to S/PDIF converter / Active Interconnect.
"In order to supply clean power to the on-board circuitry, the Bridge uses a combination of power supply filtering and an newly released power down regulator. Power coming into the device is first PI filtered (CLC), which gives a two-pole attenuation for noise above roughly 3 kHz. This works to eliminate high frequency noise, which down-regulators are typically not as good at rejecting. This filtered signal, which is slightly less to 5 V (due to resistive elements in the passive filter), is down regulated to 3.3 V for the digital electronics, and an separate 3 V line for the clocks. Note that down-regulators tend to be excellent at rejecting noise at DC and lower frequencies, the rejection ratio falls off at higher frequencies. The combination of an initial LC filter and a regulator with high PSRR (70 dB at 10 Hz, a reduction factor of over 3,000), ultralow noise regulator insure that the clocks and the digital circuitry can operate as accurately as possible."
"In order to isolate the output from the (potentially noisy) computer ground, and to avoid the possibility of ground loop noise, SPDIF commonly employs an output transformer. We use a small, high-quality output transformer, which allows excellent isolation and signal integrity in a small package." - Halide Design
Removing unneeded internal circuitry and improving The Bridge's use of dirty computer power were two critical first steps. Getting to the next level of performance required the use of an asynchronous USB implementation. Not to be confused with Asynchronous Sample Rate Conversion (ASRC). Jonathan and Aaron were not satisfied with the existing adaptive USB or off the shelf implementations found in most USB audio devices. These guys look at everything from an engineering viewpoint as well as an audiophile sound quality viewpoint. Using either perspective it's easy to see or hear the advantages of an asynchronous design. (See Asynchronicity USB Primer here on CA for additional information). Halide Design didn't settle for just any asynchronous design as The Bridge needed to be completely plug n' play without additional device drivers to achieve the "Active Interconnect" concept.
Jonathan and Aaron contacted Gordon Rankin of Wavelength Audio who developed Streamlength™ asynchronous USB code and licenses it to a limited number of high end audio manufacturers. Based on my conversations with Gordon it's evident he likes Jonathan and Aaron and thinks these guys have great potential as well. It should be noted that Gordon doesn't license his code to just anyone. Fortunately Halide Design was able to acquire the Streamlength™ license from Gordon and implement this asynchronous USB code in The Bridge.
The Bridge ships with a captive six foot USB cable that is capable of being extended with a standard USB extender or a much better optical USB extension and isolation device. The six foot cable length is a bit short for my system as I house my music servers outside my listening room. I typically use three meter USB cables that passthrough a port in the wall from my music servers to my audio components. Without a USB extender readily available during this review period I moved my C.A.P.S. silent music server next to my Berkeley Audio Design Alpha DAC. This eliminated the need for a longer USB cable but was a little inconvenient. The Bridge truly is plug n' play without the need to install any software of drivers. It supports bit transparent digital audio output at 44.1, 48, 88.2, and 96 kHz. The Bridge is available with Eichmann RCA or standard 75 ohm BNC terminations. During the review I used the BNC version connected directly to the BNC input of my Alpha DAC. Both versions are cryogenically treated and have a fully isolated output using a high quality digital audio transformer.
The Bridge To Sonic Bliss?
Simply put, I was surprised by the high performance of The Bridge. I had an inkling The Bridge would be good based on its designers and the Streamlength™ USB code, but I didn't expect it would be this good. Playing all types of music The Bridge offered wonderful separation of the instruments and a clarity from top to bottom that was close to my Lynx AES16 PCI card. During the review I purchased Reference Recording's Crown Imperial by the Dallas Wind Symphony from HDtracks at 24 bit / 96 kHz. I own the HRx version at 24 bit / 176.4 kHz but The Bridge does not support sample rates above 96 kHz. Track eight on this album, Michael Daugherty's Niagara Falls, has become one of my favorites as a civilian and as a reviewer. Listening to Niagara Falls through The Bridge seemed to open another complete octave at the top end compared to other USB to S/PDIF devices I have used. The resolution and extension was so good I contacted a couple colleagues in the industry to discuss why I wasn't getting this level of performance from other converters. Specifically the M2Tech hiFace. My comparison between the hiFace and The Bridge was not a scientifically thorough longitudinal study conducted under controlled conditions. I have many hours of listening left before writing the complete hiFace review. It's entirely possible I'll be able to squeeze improved performance out of the hiFace in the coming days and weeks. As of now The Bridge is definitely my go-to USB to S/PDIF converter even if it is limited to 24/96 and below.
Another clear sign of The Bridge's great performance can be seen through my listening habits during the review period. When I first placed The Bridge in my system I had the urge to listen to tons of music just to hear what it sounded like through The Bridge. I listened to a minute or two of what felt like hundreds of tracks. After twenty-four hours of this kid-like listening style I fell into complete album mode. I listened to whole albums one after the other. In the case of Shelby Lynne's new album Tears, Lies, and Alibis I listened to the same album three times in a row all the way through. This type of listening does not happen with every component and especially new components I'm not accustomed to hearing in my system. Sure the extremely low jitter specs of The Bridge play a role in its performance, but it's much easier for me to judge performance when my listening habits are altered by a component. I have other audio components here that can't hold my attention more than one or two minutes. The music through these components is simply inaccurate and unappealing causing my brain to tune out.
During my last listening session with The Bridge I played the Anthony Wilson Trio's Jack of Hearts. This is a terrific album musically and sonically. I often play this album to hear how accurately components can reproduce drums and cymbals. On many mainstream recordings drums sound like someone is striking a piece of paper with a stick. This can make sonic quality judgments nearly impossible. Not so with Jack of Hearts. As far as I could tell The Bridge reproduced this recording with great accuracy. The drums sounded very good with space around them, appropriate reverb trials, and sharp transients. I'd have to ask Audioquest's Joe Harley for a 100% accuracy check as he was involved in the production of this fine album. Again, The Bridge performed great and was a pleasure to have in my system.
Throughout the review I used J River Media Center v14 and v15 with WASAPI output. I was able to achieve bit transparent output without jumping through any hoops. I used the C.A.P.S. server running 32-bit Windows 7 Ultimate edition.
The Halide Design Bridge asynchronous USB to S/PDIF converter has earned a well deserved spot on the Computer Audiophile Suggested Hardware List (C.A.S.H. List). This simple, small, single cable solution incorporates innovative design and the current holy grail of USB implementations asynchronous transfer mode, not to be confused with Asynchronous Sample Rate Conversion or ASRC. There are some fabulous DACs around without USB or FireWire input that will benefit greatly from the Halide Design Bridge. The Bridge enables audiophiles to use these existing DACs with almost any computer audio system available today. At $450 The Bridge is a relatively inexpensive component with great potential to bring any audio system into the future of high end audio reproduction. I highly recommend The Bridge from Halide Design to colleagues and Computer Audiophile readers around the globe.
- Price - $450
- The Bridge Product Page - Link
- Product Design Details - Link
- Halide Design Store - Link
Verity Audio Fidelio loudspeakers, McIntosh MC275 amplification, Richard Gray's Power Company High Tension Wires, Berkeley Audio Design Alpha DAC, Wavelength Audio Proton, Ayre AX-7e Integrated Amp, C.A.P.S. server, Bel Canto USB Link, Halide Design Bridge, dCS Debussy DAC, dCS Puccini U-Clock, Kimber USB Cu, Kimber USB Ag, Benchmark DAC1 PRE, Kimber Select KS1011 Analog Cables, Kimber Select KS2020 Digital Cable, Kimber Monocle X Loudspeaker Cable, ASUS Xonar HDAV 1.3 Slim, Apple iPad, Sonic Studio's Amarra, M2Tech hiFace, Weiss Engineering DAC202, Lynx Studio AES16 Digital I/O Card.