Equipment Review No. 2  -  June 2003

Audioquest Optilink-5 Optical Cable, 1m length
$425
Audioquest
8710 Research Drive
Irvine, CA 92618
http://www.audioquest.com
949-585-0111

Basic Description

Toslink (EIA-J) fiber optic cable utilizing 65 Quartz (glass) fibers.


Associated Equipment

System #1: Krell DVD Standard, Krell Home Theater Standard, Krell Theater Amplifier Standard, B&W Nautilus 802 Speakers, Audioquest speaker and Interconnect cabling, Panamax 5500 Power Conditioner, Audioquest VSD-4 Coaxial digital cable ($325) and Monster Interlink Lightspeed 100 ($40) for comparison testing.

System #2: Meridian 568 Preamplifier, Toshiba SD-3800 DVD player, Mark Levinson No. 29 Amplifier, Smart Devices Power Conditioner, Audioquest Interconnect, Triad Silver Monitor speakers, Triad Silver Subwoofers (2), Discovery Coaxial Digital cable (<$100) and a generic optical cable (that normally comes free with a satellite receiver~<$10).


Theory

I never intended to do a review of digital cables. Everyone has different opinions on how much impact cables have on a particular system, and some believe that there is no way a digital cable can have its own sound. Many others believe that cables are the final step in “tuning” a system for optimum performance, and that there is no one good recommendation.

We have all heard the stories about how bandwidth-limited the plastic Toslink cables are, how the connections at the equipment ends are poor—resulting in high jitter, how any serious bend or kink in the cable can cause complete loss of signal, and on and on. Basically, we are told to use Toslink cables only as a last resort, and that even a cheap coaxial cable will provide superior performance. And, don’t forget that the signal originates as an electrical signal and is then converted to an optical signal by a $.10 part right as the signal leaves the transport’s back panel. However, there are some advantages, including: resistance to electrical interference, low loss over very long runs, and lack of a ground connection that can possibly prevent ground loops (for equipment located far away).

I remember an old comparison test of some inexpensive (<$100 as I recall) digital cables in Home Theater Magazine a few years ago. They found that with a PCM signal (the 2-channel digital audio signal coming out of a CD player), certain cables sounded different and subjectively better. Their recommendation at the time was for a coaxial cable. As I recall, all the coaxial cables outperformed the optical cables with a PCM signal.

Flash forward to a month or two ago when I was having a conversation with a gentleman from Audioquest. Apparently, there is a transition going on in some of their interconnect cables, and the new cables will include batteries to keep the dielectric constantly charged. This, purportedly, is the advantage of so-called cable “break-in.” The normal break-in process (according to Audioquest) takes weeks. But once the cable is unplugged and/or no longer in use, the cable reverts back to its original state. The broken-in cable is supposed to sound better. In the past, I’d seen/heard cables that plugged into the wall to accomplish the same exact purpose.

Maybe there is something to it? In any case, whether you believe the hypothesis or not, the advantage of an optical cable is…no break-in is necessary. So, if you turn your components off, you don’t have to worry about losing the charge on the dielectric. Therefore, according to Audioquest, the optical cable will have an advantage in this circumstance.

Another important point that needs to be made relates specifically to the Optilink-5. Normally, an optical cable is constructed with a single fiber. In both the Optilink-3 and Optilink-5, Audioquest utilizes multiple fibers to transmit light from end to end. In the Optilink-3, the fibers are polymer, while the Optilink-5 utilizes Quartz. Audioquest claims that you can hold one end of the cable against a well-lit printed page, and via a magnifying glass, view the text at the other end with the naked eye. Apparently, this shows how exact the transmission of light is with the Optilink-5. Unfortunately, I did not have a magnifying glass to try this.


Setup

In system #1, I ran the coaxial cable from the DVD player to a second input on the Krell preamplifier. This allowed me to switch back and forth between the optical and coaxial cables for the comparisons. In order to compare the optical cables, a friend helped to switch while I listened--going back and forth at request. I did the same while he compared the cables as well.

In system #2, I connected the optical and coaxial cables similarly to system #1. I switched back and forth on two different inputs on the preamplifier via remote. Switching optical cables was more difficult, but my rack is accessible from the back, and usually took no more than 30 seconds.

The Optilink-5 is fairly heavy duty for an optical cable and has a somewhat large diameter making the cable less likely to bend and/or break. The connector at the end is easy to grip and allows easy connection to components. (The Monster Lightspeed cable connector would sometimes slip back and it was hard to tell if it was secure.)


System #1—Comparisons to Audioquest VSD-4 coax cable

The initial comparisons were with the VSD-4 coaxial digital cable. I put on track 3, “O Ultimo Por Do Sol” from the soundtrack to Woman On Top. The optical seemed to produce a touch more high frequency sound. It was so slight that I had to go back and forth several times to convince myself it was there, and it was only noticeable on certain parts of the song. There was an additional bit of sibilance that the coaxial cable seemed to impart that was missing with the optical connection. The coaxial sounded richer, but it was most likely additional “grunge.” I liked the texture of the sound better with the optical cable. The differences were extremely subtle, but I assume that anyone willing to spend over $400 on a digital cable is listening for those differences and willing to pay for them. Further listening left me with the impression that the coaxial cable was compressing the range and emphasizing the middle. The optical cable seemed to put less in the way of the music.

Next up was track 5, “Please Send Me Someone To Love,” by Sade, from the soundtrack to Philadelphia. Again, the optical cable seemed to produce more detail. The bass sounded deeper and tighter somehow. With the coaxial cable, there was added richness and the voice was warmer with a slightly puffy quality to it. With track 1, “Ole,” from John Coltrane’s Ole, I noted similar differences. The piano sounded a bit dull with the coaxial cable although the high frequencies sounded smoother.


System #1—Comparisons to Monster Cable Lightspeed 100 optical cable

For the next group of comparisons I put on track 6, “Tropicalia,” from Beck’s Mutations. I did the switching and let my so-called audiophile friend call the shots. He told me when to switch back and would ask which cable was currently in the system. Once he got a handle on the difference in sound, he told me which one he preferred. He preferred the much cheaper Monster Cable. In his words, “This cable [Monster] has more life to the sound, the other [Audioquest] is duller by comparison.” I switched to track 2, “Eye In The Sky,” from Alan Parson’s Project Eye In The Sky album. At this point with just a switch once or twice, he picked the Monster each time as his cable of preference without any trouble.

He seemed to be able to hear the difference easy enough, but did not like the sound as much with the Optilink-5 in the system. When it was my turn to listen, I tried to focus on the areas that he seemed to find objectionable. My preference was quite the opposite though. The punch/presence that he seemed to prefer came off to me as just added hash in the high frequencies. I had a clear preference with the cymbals playing for the Optilink-5. A good analogy would be to the sound of a speaker. At first when you hear a speaker that has an exaggerated frequency response in the highs or lows you tend to prefer it. But over time, the other speaker that isn’t quite as “emphasized” begins to sound more natural and realistic. This is the best way to describe the differences although they were on a much, much smaller scale. I had to remind myself that I had over $30,000 of equipment going.


System #2—Comparisons to freebee optical cable

I’m sure there are thousands of people using the optical cable that came with their $249 DVD player to connect to their surround receiver. Well, for this part of the comparison I used a $149 (at retail) DVD player as my transport, and used as cheap an optical cable as I could find.

I began with track 3, “Let’s Fall In Love,” from Diana Krall’s When I Look In Your Eyes. The sound of licking from Diana’s lips, guitar plucks, and general transient sounds were more evident with the Audioquest cable. In parts when the vocals got louder and softer, the transitions seemed more dynamic and pronounced. At first, I thought the image was slightly smeared with the cheap cable, but I then realized that it wasn’t firmly plugged into the DVD player. In any case, the Optilink-5 sounded more liquid—Diana sounded as if she were standing closer to the microphone, and the lower register of her voice sounded huskier and more solid. I was drawn into the performance more with the Audioquest optical cable in the system.

I switched to track 7, “Love Song,” from the Mobile Fidelity release of Elton John’s Tumbleweed Connection. The sound with the generic cable was muted, smaller in size, and less present. With the Optilink-5 there was a sense of greater resolution and definition—the voices were clearer, the instrument was more natural and eased out of the speaker. The difference was striking. I did not have to strain to hear the differences. Where with the other tracks I spent many minutes listening to sections over and over and going back and forth, with this cut it only took two or three switches to hear what I consider to be a healthy improvement.


System #2—Comparisons to Discovery coax Digi-Cable

For the last two selections, I chose classical pieces. The first was Beethoven’s Romance, Op. 50, track 5 from RCA Victor 7777-2-RC with Joseph Swensen and Andre Previn conducting. The optical cable sounded a bit toned down in comparison to the coaxial cable. With this cut, I preferred the sound of the coaxial cable, although the difference was not huge. Recording quality is just average on this disc, but differences were still discernible.

Track 2, “Banditen Galop,” from Telarc Sampler #3 is always a lot of fun. It has great dynamic range with good bass, and if you aren’t ready for the “gunshots” you might just jump out of your seat. Again, my preference was for the Discovery cable due to a feeling of fuller bass and a richer presentation overall. There was a difference in high frequency extension and air. This is the kind of difference I hear by turning the upsampling on and off in the surround processor. The comparison only served to reinforce my original choice to use the Discovery coaxial cable. I won’t be so quick to ditch this cable.


Conclusion

I definitely have been in the camp of poo-pooing optical cables for the last few years. Although construction and durability will always be a concern with cheaper cables, there is clearly a new and better breed than ever before. Some components do not offer coaxial connections so, in that case, I will be recommending a high quality Toslink cable from now on. It was clear to me that the Optilink-5 outperformed all the Toslink cables I had on hand for comparison. It even managed to outperform an over-$300 coaxial cable. It will still be necessary to evaluate preferences and different system “sounds,” but the Optilink-5 gets a solid recommendation.

- Brian Bloom big_brian_b@hotmail.com

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