Ortho Spectrum Tuning Devices
Stephen Yan
6 December 2000


Products under review:
CD Tuning Plaster: price $25.00
Line Harmonizer RA7000L: price $75.00
AC Harmonizer AC-21: price $65.00
Balanced Insulator CL-707: price $65.00

Delve Audio
20 Andrea Drive, Caldwell, NJ 07006
Contact: Mr. Oliver Solomon
Email: oliver@delveaudio.com
Web: http://www.orthospectrum.com/

CD Tuning Plaster $25.00

These are small, felt-covered discs about 1.5 cm in diameter, and comes with a self-adhesive backing to facilitate mounting on most surfaces. The recommended application is to place three in a triangular formation on the label side of the CD, and play the CD as per normal. However, a visit to the dealer also revealed the discs doing duty atop each EL84 output tube - presumably their damping properties are also deemed suitable for taming microphonic valves. But their primary use is to dampen spinning CDs, and first off, I must warn the prospective user that these babies are powerful things. They affect sound in a manner that is way off proportion to their size. With the use of the discs on CDs as recommended, there was a slight reduction in air and ambience, although it did seem to control unwanted resonances. Then I tried them on my tubes (2 output, one 6SN7GTA input) and the results were much better. Before long, I was experimenting with other locations and soon I was sticking little felt discs all over the system. My advice is to stay away from the direct sound-making components, such as driver cones and perhaps even the CD itself. But careful experimentation on loudspeaker baffles, the CD disc tray, and most other components subject to spurious resonances yielded extremely positive results. For around $25 per box of 30, they are an inexpensive tweak that every self-respecting audiophile should try.

Line Harmonizer RA7000L $75.00

I must admit to a lot of skepticism when I first saw this product. After all, it goes against one of the implicit tenets of audio system building - "the less connections in the signal path, the better". In pursuit of this ideal, there are those who will surgerize their amplifiers to bypass not just tone controls (if any), but input switches as well. The thought of putting two extra male and female RCA jacks into the system sounded like anathema. Having tried them on my CD playback system, I can safely say one thing - they work. The background really got darker, the noise floor was lowered. This allowed instruments and vocals to stand out more vividly and clearly, no mean feat. But the improvement on my vinyl playback system yielded less categorical results; I could detect a difference, but only if I listened hard enough. The only reason I can think of for this is that the former system has no EMI/RF treatment whatsoever, whereas the latter uses EMI devices, a high current Tice power conditioner, Tice power cord, etc. Conclusion: if it is applied on a raw system, the benefits can be quite considerable. But if your system is already well treated, then the Line Harmonizer may help you eke out that final bit of resolution, but only just.

AC Harmonizer AC-21 $65.00

This is one of the most overtly tweaky looking things I've ever seen. It consists of a 13-amp three-pin plug (common or-garden type) but without any wire leading out from underneath. There is a piece of circular wood, like a donut, rigidly attached on its back. And that's it. How does it work? Well, unlike the Little Mead box that I use on the main system (which is meant to be plugged into the first outlet of a distributor strip, or at least immediately upstream of whatever component you are treating), the AC Harmonizer AC-21 plug goes at the end of the power line, i.e. it affects the return leg of the mains circuit. Indeed, my experience bore this out to be true. I had two 13-amp outlets on my wall, and visually judging from the position of the DB box, I plugged the AC-21 plug into the upstream outlet a la the Little Mead. I heard little, if any difference. However, reversing positions (as intended) allowed me to hear an increase in depth and soundstage, and slightly better imaging. The juice feeding my system is notoriously dirty - one of the disadvantages of living in the middle of town - but with the AC-21 plug, spurious mains noises were drastically reduced. Finally, I could listen to music without worrying about somebody in the next apartment turning on his hair-dryer or washing machine and causing my amplifier to whine in sympathy. If you've got similar problems, check the EMF plug out and see what it can do for you.

Balanced Insulator CL-707 $65.00

In many ways, this item is the most difficult one to review in the pantheon of Ortho-tweaks. It looks simply like a bigger version of the CD tuning discs. About 5cm in diameter, it resembles a piece of felt material sandwiched between two slices of leathery 'bread'. Installation was as simple as the foregoing devices - just slip one under each foot of your CD source and sit back. While I can't detect any variations in thickness, just by visual inspection alone, I'd be worried about unbalancing the CD player with uneven discs. Unless your player is heavy enough to sink the discs in such a way as to level them automatically, any tilt caused by uneven discs can affect sound performance. This becomes more crucial the better the quality of your CD player. Any theoretical benefits of the feet would be offset by the tilt factor. Now, some of you may be thinking that I'm overly retentive about these sorts of things, but you can never be too careful; even micro-level disparities can cause audible degradation. So it was that when the feet went under my relatively light CD player, I couldn't hear any improvement in performance. On the other hand, placing them under my hernia-inducing power amplifier overcame my phobias and I was happy to believe that the amplifier is benefiting from some measure of damping as well.























































Luminous Audio