Please note: the intro to this posting was revised , so that I can be more specific in the questions I’m posing.
I read through this entire thread, as well as others on this topic. I plan on buying an ultrasonic cleaner to replace a 30 year old Nitty Gritty Pro. I just want to buy a new machine and don’t have the time or expertise to build my own or clean using dish racks for drying, etc. In light of that, the two best choices for ultrasonic RCMs appear to be the KL Audio or the Audio Desk. I have used a store demo model of the Audio Desk, as noted below. I have never seen or used the KL Audio, and my comments below are based only on what I’ve read.
If the choice must be made between those, which do the experts on the forum prefer in three areas:
(1) For records that are new? Which machine, the KL Audio or the Audio Desk, will make the most audible improvement on LPs that are already in new condition?
(2) Personally, 90% of the records I clean will be used records (or new records) that have already been cleaned on a Nitty Gritty or are used in near mint or mint in condition, as that is the bulk of my LP collection. In the case of used records previously cleaned on a Nitty Gritty, I noticed an additional improvement, specifically in treble, but occasionally on the entire frequency range, when cleaning again on an Audio Desk. (If I didn’t notice an improvement, then buying the Audio Desk would be a waste of money.) Would that be the case with the KL Audio?
(2a) For 90% of my cleaning of my existing record collection -- Which unit, the KL Audio or the Audio Desk, would be better on new or used records previously cleaned on a Nitty Gritty?
(3) Used records not previously cleaned. I don’t buy used records from junk bins or estate sales that have been trashed. So used records would generally be in VGL or Near Mint condition, but are probably in the original paper sleeve, and some might have a fine layer of accumulated dust.
(3a) I can always clean those records first on my old Nitty Gritty. If I did that, which unit, the Audio Desk or KL Audio, would do the best job for a second cleaning?
(3b) And which unit, the KL Audio or the Audio Desk, could possibly be used for “one stop” cleaning so the additional time of cleaning twice might not be necessary?
Having read all of the threads, I offer my own conclusions below as to the differences between the two units.
I hope the below summary of the differences between the two units might be useful in the future for anyone trying to decide between the two units. Please correct any misstatements or erroneous conclusions!
I have listed the various factors to consider.
POWER OF ULTRASONIC CLEANING -- I'm leaning towards the KL Audio, simply because it has nearly four times the ultrasonic cleaning power of the Audio Desk -- and the entire point in spending $4,00o on either machine is for the ultrasonic cleaning. The KL Audio has four 50 watt transducers that, based on the description, are aimed directly at the LP in a horizontal or perpendicular fashion, with two per side. The Audio Desk has only a single transducer. Audio Desk apparently won't confirm -- or admit -- what the size of that single unit is, but it is probably half the size of one of the four KL Audio transducers. And that smaller and single transducer is located in the rear of the Audio Desk, and is aimed upwards to cover both sides of the record from the edge. Essentially half of a weaker transducer per side, compared with two more powerful transducers per side.
DAMAGE CAUSED BY ULTRASONIC CLEANING? -- Audio Desk strongly implies that KL Audio is using transducers that are too powerful for vinyl and might damage records (see the comments from Audio Desk in the Stereophile review.) But that assertion is completely undocumented, and no proof for the assertion is provided. KL Audio responds that they have a patent on their safe way to provide the greater ultrasonic power. Furthermore, I have not seen a single allegation, or even one confirmation, from any owners of KL Audio, that the machine damages vinyl. So that bald faced assertion by Audio Desk strikes me as more of an undocumented cheap shot than anything else.
HEAT FROM ULTRASONIC CLEANING -- Of greater concern is that the original model of KL Audio heated up the water to the extent that after cleaning 3o or more LPs in a row, an LP would appear slightly warped, I assume in a concave or convex fashion, but then return to flat when dried. That was reported in the Absolute Sound review. However, the two newest units of KL Audio included a pump that sucks water past a fan to cool it off. My understanding is that you'd have to clean a very large number of records, one after another, and on the shortest dry cycle to see any momentary warping, before the record is dried and returns to flat, especially with the newest cooling modification. I'm not likely to clean enough LPs at one time to encounter that in any case.
ADDITIONAL CLEANING BY THE USE OF CLOTH FIBER BARRELS -- The Audio Desk appears to offer other advantages as compared with the KL Audio but I now wonder if these other features were included to compensate for the single and weaker transducer. Specifically the use of the four cleaning barrels. At first, I thought those barrels were an advantage in the design of the Audio Desk, as they would vigorously scrub the vinyl grooves, but I now wonder if KL Audio simply doesn't need them due to the greater ultrasonic power? If that is true, then it means that with KL Audio only water is touching the record without any risk of using barrels that rub water, that may contain debris, against the vinyl.
The key question is whether the KL Audio unit cleans as well as the Audio Desk without the need for the barrels, due to the greater power of four ultrasonic transducers as compared with one weaker transducer in the Audio Desk. That is the key issue and difference related to the effectiveness of both units in cleaning records.
USE OF CLEANING FLUID -- The Audio Desk uses a fluid emulsifier to help the water stick to the vinyl. Some reviewers believe this is a big advantage for the Audio Desk. Others believe that this fluid forms a residue that can be heard, and therefore must be removed in yet another cleaning cycle in clear water on an additional machine. If true, this would defeat the purpose of the cleaning fluid in an all-in-one machine. The real question is whether KL Audio, with four powerful ultrasonic transducers, and using water alone, can do as good a job as the Audio Desk with a combination of a single weaker transducer, four cloth barrels, and the cleaning fluid. KL Audio does appear to concede the point, at least in part, admitting in some reviews that they can't remove a large finger print, to offer one example. But I don't generally see fingerprints on used records, so the real question is how both units clean somewhat dirty old used LPs as well on new LPs. Which units do the best job of removing dirt and stuff from the grooves? Using only more powerful ultrasonics, or the combination of a weaker transducer, but with barrels and fluid?
EFFECTIVENESS OF DRYING CYCLE -- The KL Audio unit appears to be superior when it comes to drying. I encountered the problem of LPs that still had water on them after drying in the Audio Desk. The Audio Desk also has the vinyl lips. I assume the purpose of those is to help the drying cycle, by acting as squeegees to remove water, probably due to underpowered drying fans. But those lips can trap debris and rub it against the record, and based on comments here, can be difficult to replace. The KL Audio unit apparently has significantly stronger fans for drying, and records are always completely dry -- with no need for vinyl lips.
FILTER TO REMOVE DEBRIS FROM WATER -- Another advantage of Audio Desk is that it has a filter, whereas the most expensive model of KL Audio doesn't. The Audio Desk needs this filter, since the water with any debris is rubbed against the record by the barrels. But the Audio Desk filter is just a piece of styrofoam, and my observation is that in actual operation, a large quantity of the water is sucked *over* the filter thereby bypassing it in any case. KL Audio has less need for a filter, as nothing touches the record except water. However, the newest and less expensive KL Audio includes an in-line filter, and based on the photos in the manual, it appears to be a true water filter, and my guess, is more effective than a piece of styrofoam.
REMOVAL OF DEBRIS AND CLEANING OF UNIT -- There is no way to clean out the bottom of Audio Desk. It can be flushed out by running water through it -- but that is the extent of cleaning, and there is no way to see the level of debris in the bottom, and no way to directly clean it out. The more expensive KL Audio unit can be opened to clean out the bottom circular area where debris collects but apparently that is a bit difficult with sharp edges -- but it can be done on the KL Audio, whereas that is impossible with the Audio Desk. The newest and less expensive KL Audio unit solves that entirely by using an external water container or jug, which can be flushed out or even replaced.
GENERAL FINISH OF THE UNITS -- The Audio Desk is plastic whereas the KL Audio is stainless steel. The less expensive KL Audio is the most practical, with an external jug or tank that can be visually inspected or easily replaced. It also comes with an in-line filter. Also an external pumps if it should break. But is literally put together with velcro so looks worse than either the Audio Desk or the more expensive KL Audio unit.
RELIABILITY -- The developer of Audio Desk appears to be notorious for not responding to emails reporting problems and for taking 3 to 6 months to repair units from Germany. And he appears, based on my own interaction with him, to offer lame excuses for obvious problems that require repair, but he won't admit or acknowledge that. KL Audio, on the other hand, is based in the U.S., and gets generally positive marks for quick repairs. And the KL Audio is built like a tank. Getting KL Audio to call me back, is, however, very difficult, based on my experience. And then is when my voice message said I wanted to buy a unit. How quickly they respond to voice messages reporting problems would be the question.
For all of the above reasons, I am leaning to the less expensive KL Audio unit -- more powerful cleaning by a factor 4, and more powerful drying. It is also easier to set cleaning and drying times, and for new records that may only need a minute or so of cleaning, and 2 minutes of drying, KL Audio then offers a 3 minute cycle rather than 6 minutes minimum on the Audio Desk.
I welcome any corrections and comments from the experts!