HumminGuru ultrasonic RCM FTW! (The one from Kickstarter)

So I pledged 3 units on the Kickstarter in spring and therefore was one of the first to get shipped, but the others will be sent out soon, for anyone desperately waiting.

First impressions are very good, it is well built, everything fits, it came complete with all the replacement kits I ordered. Very impressive Kickstarter effort, and very good value for the ~300 euros I pledged per unit. (Dunno what the normal retail price will be). First some pics:

The 7" adapter, there’s also one for 10". (They were included for Kickstarter backers because all the stretch goals were met, are probably extra for normal purchases):

The included switch mode PS, but I’ll get a linear one for 5K to see if it improves the cleaning result :crazy_face:


Manual, excuse the occasional fat fingers:

First two for the adapters:

And the RCM:


And the first cleaning impressions:

  • Quick and easy handling, you pour the water into a little removable tank (which also makes it the correct amount), fill it into the slit from the top, after the cleaning cycle it’s pumped back into the tank automatically. BTW forget about the maintenance tool used as a water level indicator - you want 400 ml exactly (it’s marked on the tank) for 12" records, then the water level includes the run-out groove.
  • There’s a washable, replaceable water filter at the entry of the tank, and an also washable/replaceable air filter for the drying fans.
  • The 400 ml water is a sufficiently small amount that simply replacing it after each run is possible, at least if you only clean records for immediate playing. It’s easy to remove the water filter too.
  • Default of 2 minutes washing and 5 min drying was enough for me
  • The noise is surprisingly low, much better than the ultrasonic cleaner I used previously (which was a regular 5L ultrasonic cleaner tank with a rotating spindle on top, cheap from Ebay and similar to the one sold by Kuzma).
  • The buttons for choosing options and clean/pause have a bit of a flimsy feel to them. Is not an issue and I am sure they are adequate, but a proper hifi company would have invested more where it really counts, in expensive-feeling haptics :wink:
  • Cleaning result seems good so far. I cleaned 2 new records that were not cleaned before. They were not noisy to begin with, but a cleaning run clearly improved it. All my other records were ultrasonic-cleaned with my other machine during lockdown. I cleaned one of them and can’t say for sure if there was another small improvement - may be. I am now searching for a dirty one I may have forgotten somewhere.

@SteveC You asked :slight_smile: @IainW @YetiZone you liked my FedEx annoucement earlier today
Here you go!


349 dollars, the actual price ? Seems not expensive at all.

The wife used to be a jeweller and when I was cleaning records with the okki nokki complained about the noise and said what you need is an ultrasonic cleaner. So guess what I’m asking for Xmas :grinning_face_with_smiling_eyes:

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According to the new humminguru dot com website, for the commercial launch (Nov 18), they are currently saying 2,956 HK$, which is 379 USD, 327 EUR, and 278 GBP. I guess plus shipping. For the Kickstarter pledge I paid 292 euro incl. a replacement part kit for 16 eur, incl. shipping, and got the 7" and 10" adapters for free. Feels like a bargain :slight_smile:

Big thanks to @Bshah, you made me aware of the HumminGuru when you started the ultrasonic cleaner thread.


OK luckily I found out / remembered that I had saved the best for last, but then the lockdown was over: My SST Records collection, all 150 of them, so plenty of dirt to choose from. They are not totally filthy and have been reasonably well cared for, but they are old, breathed much cigarette smoke, and most have not been out of their sleeves since when I had cats. I played one of them a bit and then ran it through the cleaner.

  • Like with my previous ultrasonic cleaner, much of the fine cat wool is removed during the first run, but not all of it. I had to collect some stragglers with my Dynavox brush, then I did a second run.
  • Like with my previous cleaner, the water level should nearly reach the label, so that the run-out groove is included and any cat wool in the area is reached by water, else it stays there, obviously. This is the case when using the 400 ml water mark on the tank. No worries, the water does not run down and reach the label during cleaning rotation.
  • After the second run the water was pretty yellow-dirty, so I replaced it and did a third run; not much seemed to come off this time, judging by the water.

The subsequent listening test was successful as expected - much less surface noise and better SQ, more precise and natural all around.

Success! Thanks for listening through my monologue :smiley: I’m taking questions now


t may be my next Santa gift :gift:

Do you need to change the distilled water after each cleaning or how many lps cleaned?
You just put distilled water or additional cleaning product ?

Originally they recommended to change the water after each LP, if I recall correctly. In any case they later added a water filter based on user feedback. It’s a fleece thingy that is integrated in the tank (but easily removed) so that the water flows through it when you pour it out of the tank after cleaning. It will remove dust and hairs, but of course not soluble dirt. It will depend on the state of the records. If they are cleaned already, reusing the filtered water for a while will not be a problem. The dirty LP I tried made the water yellow after 2 runs, so I’d probably want to change it anyway. And it’s only 400 ml, so what.

Antisurfactants are not typically recommended for ultrasonic cleaning (although of course people try everything, the more poisonous the better the feeling to have done the best). E.g. Kuzma are saying that it reduces the drying time, but that’s about it. And drying time is no issue here.

Anyways, HumminGuru recommend to use only distilled water, and anything else voids the warranty and you are on your own. I suppose that a drop of dishwasher rinse-aid won’t hurt, but I’d be wary of the hardcore photography stuff with lots of Xs and numbers in their names. If someone only feels the record is clean if it’s evidenced by 3,000 dead fish, this is probably not for them :wink:

Oh and BTW, it removes static perfectly as expected (my previous ultrasonic also did)


So in normal or optimal use, you need around 1 bottle of distilled water for 2 lps. I would have to buy a big stock of distilled water, or maybe I can find some bottles of 5 l .

Depending, but if they are dirty then yes. Amazon delivers it in various containers, like 5 or 25 liters. It’s not ideal because of packaging, so the bigger the container the less plastic. Local home stores and the like will also have some, maybe even with the option to return the container - depends, I don’t know. (Though Amazon has lots of choice for the paranoid, like double-distilled laboratory water :wink: )

Of course you can also run the used water through a coffee filter or more elaborate solutions - seems a common practice with all kinds of RCMs, anyway. It’s just an option to simply discard it, and this depends on the use whether it makes sense.

There are also kitchen water distillers. It takes a while and uses much power. May be environmentally better but I haven’t done the math. Of course these distillers remove only scale and are not ultra-clean like the commercial options.

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My Humminguru arrived on Monday. But crazy week means I can’t try it until Saturday!

Even faster, did you also pledge more than one? I hope you’ll make it through the week unharmed and can have fun on Saturday. And that you’ll also like it!

Can you only clean one LP at a time?

Yes, but it’s cleaned and dried in a few minutes. For cleaning several at once there are the machines that use a regular 5L ultrasonic tank like my old one, costing around 550 euro on Amazon and eBay. This was handy when I mass-cleaned my whole collection. But now that I only want to clean one before playing, this one is nicer.

What is the fundamental difference between the Humming Guru and a 6k Degritter machine ?

The Degritter uses a 120kHz ultrasonic transducer, this one uses a 40 kHz. 120 kHz create smaller bubbles and Degritter says it’s better. However Kuzma uses a 35-40 kHz machine by default and offers an 80 kHz optionally but they say it makes no real difference. Degritter also comes with / recommends a cleaning fluid. Other than that I see no real difference.

I haven’t used a Degritter and can’t speak about effectiveness differences from experience, but I would never buy a 6K RCM, so … :slight_smile:

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@Suedkiez The HumminGuru looks great, and glad it has arrived.

Thanks for taking the time to do the report. Will be following updates with great interest. This unit has been heavily promoted on social media and wondered if the relatively low proposed cost would be representative of significant design and manufacturing compromises compared to the more expensive machines, which could affect long term use and reliability. I sincerely hope not as this could the unit to bring cost effective ultrasonic cleaners to a much wider market. Similarly, I would not spend 2-4K on an ultrasonic cleaning machine either, but 0.5K is a whole other proposition. Look forward to reading more as you test its abilities - perhaps sourcing a few very well loved second-hand test records to really put it through tis paces?

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We’ll have to see about longevity :slight_smile: And I’ll update after I make it to the flea market next time.

As for the price, from the things that were posted during the Kickstarter (e.g. pictures from the factory during design and building) it seems to me that it’s simply:

  • It’s an established company who has all the tools, manufacturing knowledge, and processes in place
  • They usually produce toys and household goods, so they are not used to the audiophile concept of ripping off the customer by charging 5 times the manufacturing costs and increasing credibility by doing so :wink:
  • As mentioned, the buttons and the general build on the outside seem adequate so far, but clearly they haven’t set out to create a super expensive haptic experience

Thanks for posting, sounds great, I ordered one in the pre-sale, so hopefully I won’t be far behind.

Looking at the manual above then it looks a bit fiddly with taking rollers, filters out especially if they are plastic and prone to breakage but I expect we will be able to order spare parts after official launch.