The Bimetallic connection
A few months ago, I went shopping for a new car - one that was the Japanese high-line version of a very common sedan (I'll let you guess which one I'm referring to). The sales representative was very smooth, polished as the gorgeous paint on the cars in the marble-floored showroom. After the formalities, the first thing my new friend did was to throw a strip of metal on the floor, which took me quite by surprise as it clanged and clattered at my feet. Alex told me, 'This is the sort of metal the body panels on the Bxxx is made from. Imagine how that sounds at 100 kilometers per hour, Mr. Roger.' I was gripped with vague nausea. Then he dropped another strip that looked exactly the same. This one landed on the floor like a dead fish. 'Ah, you see Mr. Roger - all the body panels of the luxury version, they are made with special bimetallic panels. The vibration frequencies of one metal bonded to the other compliment each other. That is why the Zxxx is so quiet and refined on the road.' I was sold - on the metal strip at least.

And that, in short, is the whole story behind Cromolin Vibration Control strips from Media Access, the good folk who brought us Needle Nectar some months ago. Boss man, Paul Wakeen sent me a sample of Cromolin VC (not to be confused with the cleaning product named Cramolin) and suggested I try it. The product comes in a package of three adhesive-backed pieces measuring 1 3/8" by about 6 inches. According to the white paper enclosed, written by Don Wadia Moses, the strips are made of Cromoloy alloy and are an example of constrained layer damping at work for the world of audio. He cites some very high-tech applications, like the Nashville Network's rubidium plasma atomic clock. He claims that the resonance and microphonics problems with this studio master clock were eliminated by the application of Cromolin VC strips. Impressive indeed, and so are the before and after scope traces represented.

Constrained layer damping in the home
It seemed to me that this product was aimed primarily at the digital market, so I tried to think of a way I could test it, considering that I'm really an analog-oriented listener. Paul stressed that once the strips are bonded to anything with their adhesive backing, it would be very difficult to remove them after the first 24 hours or so. This limited my options somewhat, as many of the pieces I listen to are on loan from manufacturers who might not appreciate the ad-hoc modification.

I finally decided to cut one of the strips into little pieces and stick them to the chips in my humble NAD 502 CD player. I found that kitchen scissors work very well for this task. I went for baroque and stuck the cuttings on every chip in sight. I even managed to get a good-sized one attached to the laser housing.

I plugged the NAD into my recently re-tubed, refurbished Fisher 500B receiver with two meters of Kimber PBJ. The Quad ESL-57s were already warmed-up, so I selected a CD at random and listened. The bimetallic strips are said to facilitate the transfer of vibration away from the chips in the form of heat. I think it works. I immediately noticed improvements in the sound of my CD player. It seemed a bit sweeter and a bit more relaxed on discs like Holly Cole's Don't Smoke in Bed (ALERT 2Z 81020). I'm sorry that I can't be much more specific than this, but the resolution level of this system (and it is intentionally non hyper-audiophile) just doesn't allow for absolute blandishments. Now, I suppose I could have stuck one of those Cromolin VC cuttings on the body of my Lyra Lydian, but there are some things I'm just not prepared to do for Audiophilia, and that's one of them.

After many weeks, I began to feel that my experiment with constrained layer damping had certainly done no harm, and might very well have improved the sound of my CD player. I knew that the flimsy top case of the player had to be resonating. So after a good listen to a CD that's been getting a lot of airtime on the CBC radio network, La Luna by the Canadian Guitar Trio (Skylark 9802 CD), I popped the hood on the NAD and adhered a whole six-inch strip of Cromolin centered diagonally across the inside of the top cover. The Trio likes to let their guitars ring rather freely. They play a mixture of classical and South American arrangements with plenty of percussive effects. Musically, things can get rather busy between the three guitars and their composer friends on percussion. In back-to-back listening to the first three cuts, I found a definite improvement in the clarity of instrumentation and percussion. There was slightly improved depth, less glare, and lower string passages were no longer muddled. There was indeed a significant overall improvement.

Conclusion
This product is cheap enough that one can afford to experiment with all the different possibilities. I can see it used inside the simplest single-ended tube amplifiers right up to the most sophisticated DACs and CD 'turntables'. Why not give it a try?