Analog Corner #287: The Charles Kirmuss Vinyl Restoration System

June 27, 2023 0 By JohnValbyNation

Back in the 1990s, my friend Nick Despotopoulos and I published an article in The Tracking Angle titled “Zen and the Art of Record Cleaning Made Difficult,” describing author Michael Wayne’s record-cleaning methodology. That regimen, like the article itself, was the most comprehensive one I knew of at the time.

Though complicated and time-consuming, Wayne’s methodology produced outstanding results. His goal was not just to clean a record but to restore it to as-new condition by removing from it every contaminant found on and, in some cases, in the vinyl—impurities baked into the groove owing to heat generated during playback. With Wayne’s system, you’d know if the record’s original owner was a smoker (or a toker)—yet removing nicotine or THC deposits was but the beginning of an involved and intensive process.

Though Mr. Wayne’s system is not to be dismissed, record cleaning and restoring has changed for the better since the publication of that article, especially with the introduction of cavitation-based record cleaning—an approach that uses an ultrasonic wave to create, within a cleaning bath, energetic, microscopic scrubbing bubbles. While ultrasonic cleaning has been around for decades, its application to record cleaning was pioneered by Reiner Gläss in his Audiodesksysteme Gläss Vinyl Cleaner. Today, a number of other ultrasonic record-cleaning products are available, including the Kirmuss Audio KA-RC-1 ($870, footnote 1).

M is for machine
I first encountered the eccentric, lab-coat-wearing, stuffed-rabbit-toting Charles Kirmuss (footnote 2) at AXPONA 2018 (although he was beaten to the lab-coat shriek by Jonathan Monks of Keith Monks Audio Works, just as that company’s nominal founder beat everyone else to making a commercially viable Wet-Wash/vacuum-11-dry record-cleaning machine).


At Kirmuss’s debut at the 2018 AXPONA, a US ultrasonic distributor called iSonic had its display right around the corner, showing a machine that appeared nearly identical to Kirmuss’s—although sans his very good patented record-spinning apparatus and with a slightly different control panel (footnote 3).

Both the Kirmuss machine and the iSonic machine operate at 35kHz. Later, I ascertained from a representative of the Chinese company that manufactures these ultrasonic baths that the Kirmuss Audio cleaner is based on a standard-issue, readily available cavitation machine like the one used by iSonic—although Kirmuss told us in an email that his machine is significantly modified by his own factory. He listed several small (but possibly important) differences.

The question of the appropriate cavitation frequency is crucial. It is also contentious. There’s a broad, nonspecific scientific consensus—this isn’t controversial—that while lower frequencies clean faster, they are more likely to damage delicate materials than higher frequencies are. Higher or exceeding 100kHz—are typically recommended for cleaning delicate things—like records?—while lower frequencies, including the 35kHz range, are thought to be suitable for generic macro cleaning of, for example, dental and medical instruments. Higher frequencies are gentler (in the general case), and because they produce smaller bubbles, they can penetrate into smaller areas—like record grooves. That’s a good thing, right? So why not higher frequencies?

While Kirmuss, with his lab coat-and-stuffed-animal shtick, can sometimes appear less than credible, he seems to have given these issues some thought. For one thing, the use of a surfactant seems critical to the Kirmuss method—not just to lower surface tension so that the water can get inside the grooves, but also for its direct cleaning action, stimulated by high-energy (but not too high) cavitation bubbles. Used with a surfactant, Kirmuss says, higher-frequency machines can damage records. “We in our design do not want the full action to enter the grooves,” Kirmuss says 35kHz “is safer when compared to what is measured and witnessed with a 40KHz system. We performed the measurement by our 3D microscope”—a reference to the $87,000 instrument Kirmuss uses to evaluate his record cleaner’s effectiveness. “Lower, at 25KHz, we see no action,” Kirmuss told Stereophile. Of course, there are other 35kHz machines on the market—including the previously mentioned iSonic.

But Kirmuss’s machine differs from all of the other multidisc cleaners in a critical way: Instead of using a cumbersome “barbecue spit” mechanism to spin the records in the open cavitation vat—which means that all the records being cleaned must be the same size and must be removed from the bath at the same time—Kirmuss’s patented motor-drive system fits neatly atop the cleaning tank and is more user-friendly. You can simultaneously clean two 12″ LPs plus one 10″ and a 7″ record without worrying about getting the labels wet, and you can remove one without removing the others.

Kirmuss also avers that the distance between the records is critical and that some of the other “spit” mechanisms crowd the records too closely together. Also, Kirmuss’s cleaning tank has been modified from stock to include a side-mounted low-voltage jack to power the motor drive system. That way, the records begin to turn the moment you press the cavitation button—a small but significant convenience.

It’s also for materials
The Kirmuss Audio KA-RC-1 comes with accessories: 60ml of an antibacterial/antistatic/antifungal spray; a goat-hair brush applicator; an optical-quality microfiber cloth; a larger microfiber cloth (decorated with rabbits) to cover the work space; a circular felt mat to support the record during hand cleaning; a combination carbon-fiber/parastatic felt brush; and a bottle of stylus cleaner.

All of this costs $870—far less than at least one competing system and only slightly more than the iSonic machine and its inferior record-spinning mechanism. Granted, the accessories are not costly, but no matter how you figure it, Kirmuss doesn’t seem to be in this for the money: He’s not looking to lose money, but clearly he’s not trying to make a killing. From what I’ve witnessed, he’s more concerned with waging a worldwide war against fungus.

The antibacterial/antistatic spray is identified in the manual as a “98-99% distilled water, 1-2% propanol 1-2 diol 178 mix.” That last one is propylene glycol (footnote 4), an organic solvent used in, among other things, pharmaceutical preparations and as a food additive. It is nontoxic, although I found it to be slightly irritating when accidentally inhaled.

You have to supply your own 70% isopropyl alcohol and as many gallons of distilled water as you can carry home from the supermarket—and a spray bottle that you can fill with either the latter or with reverse-osmosis-purified water.

M is for methodology, too
Mr. Kirmuss’s methodology has evolved over the past year, though the essentials remain the same, as spelled out in a new, poorly written, messily laid out, multitypeface color manual that makes the Dr. Bronner’s Castile T soap bottle label appear tidy. (Why should an owner’s manual for a record-cleaning machine have on its very first page instructions on how to use it to clean jewelry?)

You start by filling the Kirmuss cleaner’s vat with approximately two gallons of distilled or reverse osmosis water; then add 40ml of 70% isopropyl alcohol. After that, you “degas” the fluid using a function built into the machine. (Degassing should be repeated after a few cleaning cycles; cavitation bubbles that remain in the water can decrease efficiency.)

Once that’s done, you slide the records into the top-mounted slots, start the machine, and let it run for a preprogrammed five-minute wash—the suggested default time, though you can vary it. After that, the KA-RC-1 automatically stops—and then the real fun begins. You remove the record, place it on the circular pad (which has itself been placed on the rabbit cloth), spray the antistatic/antibacterial surfactant onto the record in three evenly spaced spots, and then spread the surfactant with the goat-hair brush using small, circular movements.

Especially on older records that have been cleaned using various fluids, a mysterious white paste will appear, which Kirmuss says is the “liberation” from the grooves of the baked-on crud.

After you do both sides, you repeat the cavitation process. In the owner’s manual, Kirmuss suggests repeating the surfactant application and recavitation steps a minimum of four or five times in order to fully expel the paste from the grooves. (Previous versions of the manual suggested fewer cycles.) Once you start this process, you can not stop until all of the paste has been liberated from the grooves; otherwise, once you go to play that record, you’ll quickly coat your stylus with a nasty, gummy, white substance that’s difficult to remove. (I know some Kirmuss cleaner users have complained about their styli picking up that coating—I’ve heard from a few! Hence the revised instructions.)


This Ortofon cartridge had to be returned to Denmark to have the crud removed from the stylus following an incomplete record-cleaning via the Kirmuss method. (Photo: Ortofon.)

After a few cycles, the amount of paste pulled from the grooves diminishes, and eventually so little appears that it evaporates with the surfactant. That signals that your paste pulling is finished: Time to place the record back in the vat for a final five-minute cycle, to remove the surfactant from the record.

Next, you dry the record using the supplied optical-quality, microfiber cloth—this takes less time than you might think, given PVC’s inherent water-repellency and the microfiber cloth’s absorptive qualities—then spray the record with a few shots of distilled water and dry it again. After that, you “polish” the grooves with the parastatic felt brush, then finish by spinning the record on your turntable, spraying a small amount of the surfactant on the (cleaned) goat-hair brush, and gently pulling that brush across both sides of the record. According to Kirmuss, this last step “inoculates” the record against the growth of fungus—something every veteran record buyer has seen, especially on records that have been in humid climates.

Footnote 1: Kirmuss Audio, 51 West 84th Ave., Suite 3401, Denver, CO 80260. Tel: (303) 263-6353. Fax: (303) 862-7170. Web:

Footnote 2: See By the way, if you go to Kirmuss’s website, you will see a video shot in my listening room in which Kirmuss demonstrates his system. He wanted to pay me for shooting the video, but of course I didn’t accept. Instead I told him that I’d happily donate to The New Orleans Musicians Clinic (NOMC) whatever he was planning to pay me. When the check for $500 arrived, I deposited it and wrote my $500 check to NOMC.

Footnote 3: You can see both the iSonic and Kirmuss machine in this video, at around 43:53.

Footnote 4: That chemical name seems made-up, and Kirmuss at first disputed that the ingredient was nothing more than propylene glycol, but a subsequent correspondence made it clear.

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