Audio Ideas Guide Magazine

I stumbled on this device while checking out other audio publications on the Internet, finding it reviewed on the web page of the Los Angeles Audio Society (HTTP:/ id.htm) by a writer named Larry Calhoun, to whom I am grateful. Always interested in new technology to save old technology, I phoned the developer of the Surface Noise Reducer, Mike Stosich, to find out more about it, and ultimately requested a review sample.

Note that it is not called a noise eliminator but a Reducer. There are  tricks to eliminating transient or impulse noises, but some are not practical  or possible in real time, and the most recent, such as the CEDAR  system  requite high-powered computer process-ing. Once such noises reach a certain  magnitude, or cover a very broad frequency range, their removal is not  possible without an even more disturbing replacement. You see, such boxes  as the Esoteric Sound SNARE  operate by continuously storing the  audio signal delayed by a few milliseconds, and substituting this few milliseconds  of audio for the tick or pop. The idea is not new, incorporated in such  products as the SAE and Bouillon  tick and pop boxes of the  70s. 

However, in those early days of transistors before the advent of large-scale  integrated circuits (Leis), they could not be made to work without making  the cure worse than the disease. Not only were the circuits too slow, and  thus intrusive in their action, but the bucket brigade delays sounded like  hell, and were on all the time. As far as I can tell, the SAE, which  I reviewed years ago and finally couldn't stand listening to, substituted  real-time sound after the impulse noise to replace it, whereas the SNR  does the opposite, substituting the digitally delayed sound for the  glitch. The difference is that the delayed sound is heard only for a few  milliseconds at a time with the Esoteric Sound, but is heard almost  constantly with the older designs. As we shall note below, this is a very  important consideration with respect to sound quality, that is, transparency. 

The SNR is a slim black box with rack panels, so, as you can  see, sits nicely on top of our Bristol BP-1 phono preamp. The fact  that the BP-1 has a pair of outputs (being a pro piece, it offers  both line and cue RCA jacks) allowed a bypass path to be set up so that  I could quickly switch the SNR in and out of the system. It has  its own Bypass toggle switch, but I preferred to remove the unit completely  from the signal path to properly evaluate its acoustic transparency. 

A pair of rotary controls are also seen on the front panels, with Leeds beside them. At left the control sets an upper threshold for noise reduction to prevent distortion, while the right knob sets the actual amount of impulse noise reduction. Perhaps the manuals instructions for setting these should be quoted:  A while playing loud passages, advance the Distortion Limiting control until the THUD LED illuminates. Now Back off the Distortion Limiting control slightly. Advance the Quieting control until the NR LED flashes indicate that clicks and pops are removed. Carefully adjust the Quieting control for maximum reduction of noise without introduction of distortion. If you notice distortion during loud peaks, advance the Distortion Limiting control further until the THUD LED illuminates and thus inhibits the NR LED and resultant distortion. This may require careful adjustment of both controls; some interaction will be observed.

In actual use, I found it made more sense to avoid constantly playing  with the controls, and accept that some ticks were too big for both of  us (the SNR and me) and for both knobs, while others were too  small to bother trying to track. I ended up leaving both knobs set around  noon, occasionally cranking the NR one up to about 1 o'clock. Setting it  beyond this to catch very small ticks made the cure worse than the disease  again, causing a constant low-level sputter quality to the music. Large  scratches were also problematic, in that the substitution was a very obvious  discontinuity in the musical flow; accepting! the limits of the machine  (and using the Nitty Gritty a little more often) made for greater  musical satisfaction. 

And within its limits the SNR  does a remarkable job of minimizing  record transient noise without affecting the music. I suspect it helps  to have a cartridge that is very fast (that is, with very wide frequency  response: my Ortolan MC-3000 II is rated to 80 kHz), and a phono  preamp that has a high slew rate to avoid smearing these noise transients.  The easier the SNR can distinguish these from musical transients,  the better it will do its job of eliminating them; after all, its only  recognition criteria are speed and frequency. 

I wasn't surprised at how well the  SNR  removed ticks and pops,  since earlier versions of tick and poppers could also be made to do so,  though what they left behind instead was often just as bad, muffled bluebells  and thumps. But what did surprise me was just how audibly transparent it  was, with little penalty of any kind when the Distortion Limiting knob  was properly set. Obviously, Id rather listen to my best records without  it, but some do have ticks, especially at the edges in records of recent  years; even some pretty expensive audiophile pressings suffer from this  problem. Since I listen mostly to classical LPs, I find the value of the  SNR  greater than I might with records with less dynamic range.  However, it also has come in handy during fits of nostalgia when I pull  out all the Elvis LPs from my high school days, or some of the jazz and  folk ones from shortly thereafter. This black box can make records that  were simply too noisy to enjoy quite list enable, especially ones that  have that low-level quite constant collection of crackles. This is where  the SNR shines. 

And what about all those audiophile LPs that turned out to be less than perfect pressings, especially at the edges, but sometimes also near the label? I must say that many of these in my collection have been rendered perfectly list enable, with no sacrifice in either dynamics or resolution. The signal path is more complex, so just a little less pure, but the penalty is slight for such a significant lessening of the annoyance factor by the Surface Noise Reducer. Note again that its not called the Surface Noise Eliminator.  It wont remove background hiss, and severe damage will still be apparent, but all those middle-sized ticks can be reduced in number, if not removed entirely. Its also useful when taping LPs (its logical place being in the tape loop, of course), the ability to remove cyclical scratches (if they aren't, in fact, gouges) a particular strength.

For those of us with large LP collections which we sample often, about $600 Canadian is not too much to pay for such a device as this. I'm even planning to use it to transfer some especially beloved records to CDR., so I can play them in the car. And I suspect that libraries and archives that cant afford a $20,000 CEDAR system or a $2500 Pack burn will embrace the Esoteric Sound Surface Noise Reducer.

For the record (s) (pun intended), I'm keeping mine.

For more information call 630-933-9801.

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