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Reviewers: Marja & Henk
Sources: CEC TL5100, Audio Note tube DAC, Philips DVP 5500S SACD/DVD player, Metronome CD3 Signature [in for review]
Preamp/integrated: TacT RCS 2.0 room control system; modified Audio Note Meishu with AVVT, JJ or KR Audio 300B output tubes; Moscode 401HR [in for review]
Speakers: Avantgarde Acoustic Duo Omega; Avantgarde Acoustic Solo in HT 2.0 setting; Audio Note AN/Jsp silver-wired; Quad ESL 2905 [in for review]
Cables: Audio Note AN/Vx interconnects; Siltech Paris interconnects; Gizmo silver interconnect; Qunex 75 reference interconnect; Crystal Cable CrystalConnect Reference interconnect, CrystalDigit S/PDIF RCA/RCA and RCA/BNC, Y-cable, Crystal Cable Piccolo iPod to XLR, CrystalPower Reference AC-Eur/IEC; CrystalSpeak Reference, Audio Note AN-L, Gizmo silver LS cable; Virtual Dynamics Revelation power cords [in for review], Bocchino Morning Glory [in for review]
Power line conditioning: Omtec PowerControllers
Equipment racks: Two double sets of Solid Tech Radius
Sundry accessories: IAR carbon CD damper; Denson demagnetizer CD; Nespa #1; TacT RCS calibrated microphone and software; Exact Audio Copy software; Compaq server w/Windows Server 2003 and XP; wood, brass and aluminum cones and pyramids; Xitel surround processor; Manley Skipjack; Boston Audio Design TuneBlocks
Room treatment: Acoustic System Resonators; Gizmo's Harley Davidson cap
Review Component Retail: $1,499 for 1.5m/pr, $499 for new "serve three" battery pack

Harmonic Technology CyberLight Wave 4.25V Redux
For our interconnect shoot-out some time ago, we reviewed the Harmonic Technology CyberLight Wave 4.25V interconnect. Just to recall our findings, refer to that specific part of the review. This cable -- no, cable system -- was quite the surprise. Harmonic Technology has transferred techniques from the telecom industry -- where Heaviside worked, by the way -- to the audio realm. Analogue electrical audio signals are transformed into analog optical equivalents. Simplified, the electrical signal lights up a small bulb at the source end of the cable. The louder the musical input, the higher the voltage to result in a brighter light. In related fashion, the higher the frequency, the faster the light flickers. The light signal then transmits via fiber optics to the load end where the process is reversed and the original electrical signal retrieved. Within this process, there are no colorations or losses. Harmonic Technology was able to build the biggest part of the EOC (electrical-to-optical converter) into the RCA plugs proper. An external wall wart delivers the required converter voltage, optionally replaced by a 12V battery pack.

Listening with this cable proved a feast. Background silence and detail retrieval were profound. All music arose from a jet-black silence following the formula No signal = no light = no signal. The resultant dynamics were wonderful. However, the battery pack then needed to be decoupled from the grid while listening or you'd hear the drip-loading as clicks. In our context, the Harmonic technology cable had a problem with very loud and dynamic parts when a full orchestra kicked in. The cable clipped. Contact with Harmonic Tech confirmed that this was a known issue. Some DACs output voltages higher than the industry-standard 2 volts. Ours manages 4V without a problem. To cope, Harmonic Tech has since issued 3 versions of the cable to adjust to different signal voltages. Listening with the 4.25V version added greater dynamics to the qualities already noted with the 2V version. A remarkable thing occurs when you listen at very low levels, say background music over dinner. This cable reveals far more detail at such levels than any other cable in this comparison.

After the shoot-out was published, we had a chance to do further comparisons between the CyberLight Wave and the Stealth Indra. Even though technically this was comparing apples to pears, the proof is in the eating - to stay with the culinary theme. After long and intensive listening sessions, we identified what turned out to be the consistent difference between these two cables - timbre, the distinctive sound of any instrument or voice that is built up by the transient/decay and harmonic distribution patterns. With pitch and loudness, these patterns vary. With the CyberLight Wave fed from its battery pack, acoustic instruments tended to lose some of their smoothness. A form of glare arose around the edges, something the Stealth did not introduce. Nevertheless, the CyberLight proved to be a very promising cable system.

Going back to the rationale behind the cable, we can note the following. We're aware of the usual claims that introducing another signal conversion to the audio system must have a negative impact on the sound. In this instance, we do not agree. Yes, there is another active component in the chain, with its own signature no doubt. In our case for instance, the relatively high output voltage of the DAC is 'converted' back to the standard 2.5V at the other end of the cable. That present a 1.5dB reverse impact.

However, the Wave cable eliminates a draw back endemic to metal cables. Because the fiber optic cable is truly unidirectional, it eliminates any possible feedback between receiving and sending component. This lack of feedback guarantees a cleaner signal. When the audio signal is in transit after being converted to light, nothing can harm it. RFI or EMI are powerless until the light signal converts back to electricity at the far end. In tandem with the zero-input-equals- zero-output fact, this offers a purer blacker system background.

Except that, at the time, the power supply should really have been disconnected from the grid to avoid those charging noises. In our communications with Jim Wang of Harmonic Technologies, he agreed and told us that they were working on an improvement. Some months went by after we returned the original cable loaners to the Dutch importer until we were notified that Jim had a request for us. Would we review the new CyberLight battery pack? It promised better handling, no charging noises and a more rugged construction.

The box that arrived contained the already familiar Wave 4.25V interconnect suitable for our DAC and the new battery pack. The battery pack is a cute black box 15 cm high, 13 cm wide and 17.5 cm deep. The front has a three-way switch for charge, off and DC out and 3 indicator lights. The back has 3 outgoing 12 Volt umbilicals, a fuse and the AC inlet. With three 12 Volt outlets, the battery pack can power a complete CyberLight-equipped cable system of digital interconnect, a CyberLight Wave between DAC and preamp and a CyberLight P2A for the pre-to-amp connection.

Before operating, the battery needs at least 18 hours of charging. Some caution should be observed before installing the CyberLight cables. It's safest to switch off the entire system before inserting the cables. Switch on the DC supply to the cables before powering up the preamp to avoid switching transients. The same holds true for after the listening session - switch the CD supply off after the amp has cycled down.

After a full day of charging, the new cable system was put to work. In the time between our first encounter with the Wave cables, we had upgraded our Avantgarde Duo loudspeakers from the 104dB sensitive standard version to full 107dB Omega status. Now even more revealing, any distortion in the chain is oh-so-clear - and annoying. Without the CyberLight Wave in place, there is only a very small amount of hiss with the Meishu set to normal serious listening volume, i.e. 86dB in the sweet spot - and then only when you put your ear into the tweeter's horn. With the Waves, the hiss was slightly higher yet completely inaudible in the listening seat.

We listened as usual in sessions of roughly a concert's length and after every 4 sessions, let the battery pack rejuvenate from the grid. A fair amount of musical styles went the player and thus the cable. With the unnaturally sharp edges and timbre shifts rectified, dynamics were now handled with aplomb and the overall sound was more natural and involving. Being able to provide complete inter-note blackness, sounds truly emerge from nothing and decay not into a noise floor but the same nothing.

Having a system that is quiet by itself and can and will handle dynamics is definitely a prerequisite to enjoy the particular strengths of these cables. Besides our turbo-charged Duos, we also used a pair of the new Quad 2905 ESL planar loudspeakers in these tests. Though not as efficient as the Avantgardes, their directness proves unsurpassed. Here the CyberLight too demonstrated its virtual non-existence.

Our conclusion must be that this third iteration of the battery pack in combination with the CyberLight Wave finally brings out the best from this innovative use of technology. It took some time after the 2004 CES introduction but now Harmonic Technology has a true trump card on its hands. Perhaps this innovation was introduced prematurely before startup problems had been fully solved but now, the product is ready for prime time and considerably more affordable than the class-leading Stealth Indra. Early birds in the US who still run off the previous battery pack are ready for a big step forward as they can trade in the old pack with just $100 cash toward the replacement.
Manufacturer's website