Record Cleaning 2 – Ultrasonic

Last Updated: May 21, 2019 – see Warning!

The Nuclear Option: Ultrasonic Record Cleaning

Whilst wash & vacuum systems have been around for a good couple of decades and  provide a proven and “affordable” record cleaning system, the way to go with the best technology available today, but at a considerably greater equipment cost, is ultrasonic vinyl cleaning.

Ultrasonic cleaning uses a process called “cavitation” – in which high-frequency sound waves create cavitation bubbles in a liquid bath of water and surfactant. The cavitation bubbles produce high forces that clean vinyl in a powerful but minimally abrasive manner, penetrating cracks and recesses. Removable contaminants include dust, dirt, oil, grease, fungus, and mould release. It is perfect for vinyl because it requires zero contact with the record and gets deep into the grooves.

Two “popular” models are from Audiodesk (my choice) and Klaudio. (The Audiodesk is half the Klaudio price, but still a significant investment) The original Audiodesk ultrasonic cleaner was launched around five years ago, simply as a cavitation machine, at nearly twice the price. The “Pro” has had five years of development, adding improvements to the cleaning cycle. Great attention has been paid to the build quality of internal parts, as befits a product of this price range.

To watch a record being cleaned ultrasonically (beats watching paint dry, just not much), shot here in 1080p HD with sound at LJC Makeshift Studios in London, uploaded to YouTube.

Audiodesk Pro Ultrasonic record cleaning machine, full basic cycle six minutes. Hear your vinyl in the cleanest condition currently possible, the only harm it can do is to your piggy bank. The A/D Pro is a bit over £2k, so it is not for everyone, but I consider it well worth the expense. I’ll tell you why.

In vinyl-based hi-fi there is an information “chain of command”, running from the source – the vinyl groove wall, through stages of signal amplification, to the final sound from the speakers. It is axiomatic that any weakness in the chain leads merely to amplification of that weakness further down the chain, for example amplifying a “muddy signal”, so the biggest investment should be in things closest to the source, not the other end – the speakers. Speakers basically do as they are told, but because that is where the sound comes from, popular superstition has lead many to think improving speakers improves sound.  When you have done everything else, possibly the speakers matter.

The signal  source is the point of contact between the stylus and the vinyl groove wall. Any improvement in that point of contact and the removal of any possible interference ensures the signal (music) has the best possible start in life before it heads off through the chain of amplification, to emerge at its final destination – your ears.

The magnitude of impairment cause is important. The smallest discernable change in sound  at the groove wall/ stylus interface is one thousandth of the thickness of a human hair. The idea I have heard from otherwise sensible people that you need to “lubricate the groove” (car engine is the wrong model)   In practice anything in that vinyl groove – dust, dirt, finger-oils, cigarette smoke deposit,  mould-release, or “lubricant”  – impairs contact, creates “false information” for the stylus, which is why you want the groove as clean as possible. Cleaning is what cavitation does better than any other method, though at a price.

Audiodesk Pro in operation

 The basic six minute cleaning cycle (which can be increased incrementally from six  minutes to ten) starts with the water in the lower reservoir being pumped up into the upper chamber in which the vinyl sits, filling up to just short of the label.  The vinyl then gets about five rotations in the bath with the vinyl surface agitated between two offset pairs of fluffy rollers. This is followed by five rotations applying ultrasonic cavitation – blasting the grooves with powerful jets of air bubbles. All this time, the cleaning fluid in the upper chamber is circulated through a large spongy filter back into the lower chamber, before circulating back into the upper chamber. To finish, the record is given slow rotation with an air dryer. Vinyl emerges static free and dry, ready to play.

Because it is free-standing and self-sufficient, the machine can be co-located in a domestic environment next to the record collection or hifi, no liquid splashing on carpets, and sufficiently quiet in use not to disturb others in the house. It is operationally practical enough to be part of a listening “workflow”: select record from shelf – pop it in the cleaner – then straight onto the turntable to play. Not forgetting to increment by one a tally-sheet of the count of records cleaned , and a pencilled note”date cleaned” on corner of paper inner sleeve. (You think you are going to remember how many records you have cleaned and which ones?)

All parts such as filters, rollers and wiper blades are user-replaceable.

WARNING! (update May, 2019)

algae2Nowhere mentioned in the product literature is the risk of algae and bacterial growth in the water tank reservoir.  Over the last 12 month period of use of one tankful, on emptying the tank, I noticed significant presence of blue- green algae in the water,

Spores naturally in the air ultimately contaminate the water and the water+surfactant formula creates an attractive growing medium. Algae need very little by way of nutrient in order to grow.  Cleaning records in a contaminated water environment will contaminate record grooves, leaving minute but unwelcome residue after drying. The drying cycle evaporates off a small amount of tank water, which needs topping up, so increasingly diluting the surfactant.

dummies_tip manWhen it is time to change the water in the tank (after 100-150 records) drain it into a bowl for examination, before refilling fresh purified  water. You may see particles floating but possibly worse. Prevention of contamination requires addition of a small measured dose of sulphites to the initial filling of the tank, and to the water used for topping up. Sulphites are commonly  used to prevent growth of bacteria in foodstuffs – every bottle of wine contains sulphites!

The chemical of choice is Sodium Metabisulphite,  commonly used in sterilising home-brew and wine-making equipment. It is sold under the name Campden tablets, or can be purchased as powder (usually 100gm minimum) over the internet. To ensure against  bacterial growth, add 1 gram weight of Sodium Metabisulphite to every 5 litres of purified water.

Purified Water, as sold through a pharmacy, is water that has been purified through a reverse osmosis(RO) membrane/filter, and has Total Dissolved Solids (TDS) less than 5 parts per million. The purified water I obtained from my pharmacy measured only 3 parts per million. Distilled water is even more pure, but unnecessarily expensive.  By way of comparison, London tap water, straight from my tap, measures 400 parts per million, which is lucky, because it is suggested 500ppm is the maximum TDS for safe public drinking water.

Purified Water is by its nature very pure but comes with the disclaimer “Not Sterile” ie there is a possibility of minimal  presence of some bacteria which survive reverse osmosis purification, which over time, left unchecked, will multiply, it’s what bacteria do. The addition of one gram of Sodium Metabisulphite raises the measure of Total Dissolved Solids reading to just over 20 parts per million, ie it is still extremely pure and fit for use cleaning records, but inhibits any growth of bacteria in the cleaner tank or in the record grooves..

Economics of Ultrasonic cleaning

Filling the tank requires 4.5 litres of purified water (5 litres around £6 from chemists) and a small bottle of surfactant (Audiodesk proprietary liquid, £12 a pop, use of anything else invalidates the machine guarantee). This mix is good to clean 100-150 records, before emptying out and refilling, which is easily done, as the machine is not intrinsically heavy. Consumable water/surfactant cost is around 15 pence a  record, and the capital cost of the machine is about £1 a record to someone with a 2,000 record collection.

With vintage collectable vinyl typically £50 a record, not uncommonly over £100,  up to £5,000 for the most desirable titles, it is for you to decide if the range 0.2%  to 2% of record cost is a good investment in improved listening pleasure.

Ultrasonic cleaning goes much further than merely reducing avoidable surface noise (which it does). If that was all it did, I would not be convinced it represents value for money over other much cheaper methods of cleaning. Ultrasonic cleaning does something previous methods I have used have never done –  improving audible sound quality.  This pitches an ultrasonic cleaner into the arena of component and infrastructure equipment, where I believe it punches above its weight in cost/benefit equation, in comparison with typical high-end components say, cartridge £2,000, tonearm £5,000, turnable £15,000.

Results of ultrasonic cleaning: visual inspection

The album pictured is Archie Shepp, Attica Blues on Impulse, mid ’60s original press. Black and white overexposed forensic photos capture the amount of “garbage” present immediately before cleaning and after. This record had an ipa/vacuum cleaning a couple of years previously, but gathered stuff over time, or wasn’t fully cleaned through that process. Frankly, I’m shocked at how much garbage this record had still on the surface. The effect of ultrasonic cleaning: 99.9% clean, just a handful of specs, which may be just fresh ambient dust, or specs welded into the groove that nothing will shift. Each photo is unretouched, simply what the camera macro-lens found. (click to view at full screen)


I’d say that was near-perfect cleaning of the grooves, leaving a band of vinyl land untouched immediately around the label (safety first!). This was record was number 150 cleaned ie at the end of the life of the cleaning liquid before replacement. Beyond this, you are cleaning in “dirty” water and in danger of restoring contamination

Results of ultrasonic cleaning: A:B listening tests

Because of the danger of confirmation bias, A:B listening tests were conducted with an objective listening buddy, who had no investment in the machine. An afternoon was spent play-testing a variety of records – one never before cleaned, one twice cleaned with vacuum/alcohol cleaner, records known to have lots of surface noise, brand new vinyl, 20 year-old vinyl, 60 year old vinyl.

Result? Every record sounded much improved comparing before and after ultrasonic cleaning. Not only further reduction in surface noise, but audible improvement in sound quality – lowered bass floor, more articulate mid-band and detail in highest frequencies.

You can see the difference in dust in a photo, but can you hear the musical  difference on a rip? I know, because  I can hear the difference on a revealing hifi system. I am not convinced the step-improvement is audible on mp3 streaming through PC speakers. If it was, everything spent on people’s hi-fi systems is worthless, might as well listen to everything on your phone through Spotify. I don’t go there.

There is no doubt ultrasonic cleaning does something that convention alcohol/ bath and vacuum cleaning does not do. That could be superior penetration to the very bottom of the groove, more effective removal of residual mould release, or just stuff welded in the groove that more aggressive cavitation shifts. I was surprised how much improvement occurred with background crackle, though not expected to be eliminated entirely.

It is not just “a record cleaning machine”, it is a hifi component, just as important as your amp or cartridge. If you think of spending £2k on an improved amplifier, high-end cables, or indeed on one rare record, you begin to see the Ultrasonic cleaner in proper perspective.


An ultrasonic machine is, I believe, an essential lifestyle accessory for a collector of vintage vinyl who has had most if not all his basic needs in life met, and is able to justify spoiling themselves with this beautiful and most effective record cleaning machine. The initial cost is not for the faint-hearted, but the results in my opinion justify it.  Whether it is worth it to you depends very much on where you are in the epic journey to Vinyl Valhalla. I’m sailing through those gates right now, and the sky is blazing!