Degritter ultrasonic record cleaner

Hi y’all, just a few words on what I think is a worthy alternative to the Audio Desk Systeme and KLAudio ultrasonic cleaners.

http://degritter.com/media-kit/

I’ve been a beta tester on the Degritter for the last few weeks, and am happy to offer my opinions and answer any qs for those interested.

I believe official launch is in early May, and at this stage after a couple of quibbles in day to day use, I’m planning to keep my unit, it’s been a pretty good success, and invaluable addition to day to day life as a vinyl addict.

 

Tang, it’s all adding up.

Degritter is now an integral part of my analog setup, helping it fire on all cylinders.

All I need now is a good warp flattener and demag unit.

 

Tang, it’s all adding up.

Degritter is now an integral part of my analog setup, helping it fire on all cylinders.

All I need now is a good warp flattener and demag unit.

Marc, if you know of a good demag unit that costs less than the Degritter, please let me know.

I agree with Tang, a good RCM certainly helps, but it has much less effect on the overall sound quality than a major upgrade to a vinyl source (turntable, arm, cartridge, phono stage and perhaps cable), especially if you already have a good RCM like the Loricraft. What a good ultrasonic machine does do well is convenience. It may mean that more of your records are clean which preserves the records and the stylus. It is a real luxury to own a good ultrasonic RCM.

 

Peter, I may suggest the Degritter people seriously consider creating a demagnetiser.

Obviously the target audience is somewhat smaller than for an US cleaner, but there is certainly a niche in the market for such a device.

 

Just had confirmation the Degritter will supply with adaptors allowing cleaning of 12”, 10” and 7” discs.

 

Marc, if you know of a good demag unit that costs less than the Degritter, please let me know.

The Walker Talisman is $275

There are various plate demagnetisers on eBay for between 100 to 200 dollars not sure of efficacy

 

There are various plate demagnetisers on eBay for between 100 to 200 dollars not sure of efficacy

Demagnetizers just apply an alternating magnetic field and slowly reduce it to zero. When using a tape head demagnetizer we must slowly take it away from the head to reduce the field - switching the demagnetizer off close to the head could magnetize it.

Perhaps first we should get two copies of the same LPs and using a large strong permanent magnet try magnetizing one of them. Then listening for a difference.

 

Demagnetizers just apply an alternating magnetic field and slowly reduce it to zero. When using a tape head demagnetizer we must slowly take it away from the head to reduce the field - switching the demagnetizer off close to the head could magnetize it.

Perhaps first we should get two copies of the same LPs and using a large strong permanent magnet try magnetizing one of them. Then listening for a difference.

Hey I have no idea
But MF addressed the elephant in the room ...https://www.analogplanet.com/content/you-can’t-demagnetize-vinyl-you-can-demagnetize-record—-furutech-demag-alpha-and-stein-de3

 

Caveat emptor

Again, most of what we easily find is about immediate mechanical damage and cleaning efficiency in industry, most of the time with materials very different from LP vinyl (polyvinyl chloride , a vinyl polymer) .

Researching with google scholar on the subject presents an wide and different view. Ultrasonic exposition can have a chemical action, modifying the polymer surfaces - it can be even used to harden them. How will LPs react in the long term to this type of cleaning in unknown, and cleaner manufacturers do not have the resources to research properly on this subject - the equipment to study these effects is extremely expensive.

I am not against progress, but IMHO manufacturers should release the technical information we need to assure us that their machines are safe, as well as the results of tests they have been carrying. Probably these new machines will be safe, but beta testers are surely risking their LPs ...

Just to say that after some reading I am cowardly staying with my AudioDesk - people I know well have been using it for seven years without any secondary effect. But I recognize that the temptation of what seems a technologically better and cheaper european machine is high!

I tend to agree with all of this. There are many variables that affect the cleaning efficiency of the US process: Frequency, temperature, volume of tank, distance from transducer, dissolved gases in the liquid, chemistry of the liquid (surfactants, alcohol, etc.), coupling efficiency between transducer and tank, impedance matching between amp and transducer and output power. Without the mfr explaining in detail how their RCM operates, how do you know what you have?

The first and last parameter of the list (freq & power) are of particular concern to me, even though these two are usually spec'd by the mfr. The lower the frequency, the larger the cavitation bubbles, the higher the energy released when the bubbles collapse and the more aggressive it will be. I measured the frequency of a KLAudio US RCM (which is marketed as 40kHz) and the actual operating frequency was 35kHz (it is adjustable via a small pot on the amp PCB). The power varied greatly depending on the frequency and the load (record) inserted into the tank (the power exceeded 350W at 33kHz). While the KLAudio frequency was constant, the amplitude was not. The average power measured the rated 200W, but the drive voltage pulsed at 120Hz and the peak power was closer to 280W. Overdriving an US transducer is one of the leading causes of failure in these devices.

Like KLAudio, AudioDesk does not disclose what they are doing with the drive signal, they call it "proprietary" (secret sauce), although it would be easy to determine what they are doing if the case wasn't sealed. A lot of the industrial cleaners sweep the frequency, which may produce an average of 150W, but the peak power could be many times higher. The cleaning efficiency will be affected by the distance from the transducer as well as the angle of the record to the transducer surface. It would be interesting to see an acoustic power measurement made with a probe in the tank, rather than an electrical spec for power.

I think a bit of caution is in order concerning these machines until someone can do a technical review or the mfrs release some pertinent data on them. They seem to be marketed as "high tech", but the amplifier in the KLAudio machine is quite simplistic IMO, and does not vary that much from the cheap DIY kits available on e-Bay; the KLAudio uses a PWM controller IC to generate a fixed frequency, whereas the DIY kits use feedback from the output and are self excited, but the output stage is amazingly similar in each. The KLAudio PCB has better filtering on the AC input and is capable of 115/230VAC operation, the DIY PCB is 115VAC input only.


KLAudio amplifier PCB:


e-Bay DIY amplifier PCB:

 

I have the Stein de3 LP Conditioner and, though expensive, I don't regret the purchase.

 

Exlibris, due to an unexpected and fairly pricey vet bill, I’m going to have to put off purchases like the Stein.
But it’s one I’ll come back to.
Having to slum it w the Walker Audio Talisman demag at under 1/10 the price of the Stein.

 

I managed to get a really good deal on the Stein or else I would never have considered it. I can't say if it does a better job than machines that cost much less because I don't have any experience with them but I can say that a very hard to please record store owner in the area now uses the Stein after having been through many of the alternatives.

 

Degritter continues to produce the goods. Together w my analog reinstall, the machine is helping my vinyl sound by a wide margin the best it ever has. I really can’t recommend it enough.

 

Hello!

I'm Uku from team Degritter, a co-founder and responsible for R&D and the ultrasonic generator design. It is quite fascinating to read all the posts on this forum thread and other forums too. There are many opinions out there regarding ultrasonic cleaning, its effectiveness, damage potential etc, some well-argumented and others rather heuristic and biased. I get the feeling that the URCM (Ultrasonic Record Cleaning Machine) industry is lacking clear evidence based communication to existing and potential customers. Degritter will be trying to change that

I'm here to answer your questions. Some I will have answers to, some not. I will be posting a video on the official Degritter YouTube channel comparing different applications of ultrasonic cleaning, in laboratories and the heavy industry too, but that will take time as we are currently busy running our IndieGoGo presale campaign.

Meanwhile - ask away!

PS - how do I change my profile picture? Can't seem to find a way to do it.
PPS - I understand that I'm not allowed to post commercial content, is that correct? I'd certainly like to

 

Hello!

I'm Uku from team Degritter, a co-founder and responsible for R&D and the ultrasonic generator design. It is quite fascinating to read all the posts on this forum thread and other forums too. There are many opinions out there regarding ultrasonic cleaning, its effectiveness, damage potential etc, some well-argumented and others rather heuristic and biased. I get the feeling that the URCM (Ultrasonic Record Cleaning Machine) industry is lacking clear evidence based communication to existing and potential customers. Degritter will be trying to change that

I'm here to answer your questions. Some I will have answers to, some not. I will be posting a video on the official Degritter YouTube channel comparing different applications of ultrasonic cleaning, in laboratories and the heavy industry too, but that will take time as we are currently busy running our IndieGoGo presale campaign.

Meanwhile - ask away!

PS - how do I change my profile picture? Can't seem to find a way to do it.
PPS - I understand that I'm not allowed to post commercial content, is that correct? I'd certainly like to

Hi Uku and welcome to WBF

Feel free to post commercial content

 

Hello!

I'm Uku from team Degritter, a co-founder and responsible for R&D and the ultrasonic generator design. It is quite fascinating to read all the posts on this forum thread and other forums too. There are many opinions out there regarding ultrasonic cleaning, its effectiveness, damage potential etc, some well-argumented and others rather heuristic and biased. I get the feeling that the URCM (Ultrasonic Record Cleaning Machine) industry is lacking clear evidence based communication to existing and potential customers. Degritter will be trying to change that

I'm here to answer your questions. Some I will have answers to, some not. I will be posting a video on the official Degritter YouTube channel comparing different applications of ultrasonic cleaning, in laboratories and the heavy industry too, but that will take time as we are currently busy running our IndieGoGo presale campaign.

Meanwhile - ask away!

PS - how do I change my profile picture? Can't seem to find a way to do it.
PPS - I understand that I'm not allowed to post commercial content, is that correct? I'd certainly like to

Hello Uku and welcome to the site.

I've been doing a lot of measurements on both commercial designs such as KLAudio and also on individual components such as transducers. One of the things I noticed, the transducer is fairly sensitive to loading that is affected by the plate it is mounted too, the volume of the tank it is attached to and even the spacing and angle of the record in the tank. The impedance varies drastically which therefore changes the drive requirements and the power consumed. To a lesser degree, the temp and chemistry of the solution in the tank can also affect this. As a result, the frequency and power in the KLAudio unit do not seem to be optimum. How does Degritter compensate for this? Is there a calibration mode, or can the Degritter compensate on its own as the parameters change?

Because of the high impedance of the transducers, the KLAudio uses a HV amplifier which is fairly simplistic IMO and limited in what it can do to compensate for resonant frequency and power. Any thoughts?


RE: Profile picture, click on "Settings" (upper right portion of the title bar), then on "Edit profile picture" (left side menu under "My Settings").

First Graphic- Stand Alone transducer: Resonant frequency: 40.3kHz. Impedance: <10?
Second Graphic- Transducer on empty tank: Resonant frequency: 34.94 kHz. Impedance: 160 Ohms (>300 Ohms when filled with water).

 

Phoenix, that is a good question. We've seen too what you have: the piezoelectric transducer is a very sensitive device towards mechanical stress. In fact, that is why it is used as a load sensing unit in many high accuracy applications (https://en.wikipedia.org/wiki/Load_cell#Piezoelectric_load_cell).

What we do to compensate load drift/change is frequency sweeping. This means that we do not have a static driving frequency, rather we sweep it across a narrow but sufficient band to compensate (so you can think of our 120 kHz as a carrier frequency and the sweep frequency as a narrowband frequency modulation). There are more benefits to sweeping than this: there can not be a single frequency which excites transducers equally well, since all transducers vary in physical and electrical properties. Sweeping thus gives a more even power distribution across the transducers. This also means that the cleaning is more even on either side of the record. Not sweeping in a multi-transducer cleaning tank runs the risk of developing "hot spots" of cavitation action, a larger thermal and mechanical stress on a single transducer, possibly causing premature failure.

 

Uku-

Thanks for the quick and detailed response. I know some of the commercial tanks also use frequency sweeping; one of the concerns I have with that method is the average power may be 200W, but the peak power could be many times higher (I guess it depends on the BW of the sweep). I also thought that if the sweep rate was fixed, you run the risk of parts damage if the sweep rate finds a sympathetic frequency with a part in the tank (although as most records are fairly close in dimensions, thickness, density etc., the risk of this could be easily avoided if the Fr of the disk is known).

I'm wondering if the most efficient way of driving a multi-transducer array is to drive each one individually at its resonant frequency and balancing the power of each by adjusting the drive level?

Another question: On the KLAudio machine, I measured the impedance of the parallel array (4 transducers, 2nd graphic above). If driven by a single frequency, does the array respond as the graph would indicate, i.e. do the transducers act as a composite or lumped element at one frequency or do they still have individual Fr and impedance, so each transducer would have a different output efficiency?

 

Phoenix, in the case of Degritter, sweeping provides a power averaging, in which the minimum delivery and maximum delivery do not differ by a whole lot. Degritters average power output is 300 W. As for the unwanted resonances: we have taken care to avoid them.

Also keep in mind that at higher frequency, the energy per cavitation bubble is more than an order of magnitude less than at lower frequencies (120 kHz compared to 40 kHz). This, in fact, provides a more delicate, uniform and near-surface cleaning action than at lower power with lower frequency.

With Degritter, there are more cavitation bubbles that have a more even and denser distribution, giving an even cleaning effect.

Driving each transducer individually will be an overkill in terms of BOM cost, also design complexity. Having the transducer enseble loaded with water/physical load lowers the Q factor (on your graph), so it looks like they blend together. But they will still have uneven resonance points and resonant resistances (thus not the same power output/dissipation).

 

Here is the commercial announcement (Thank you Steve)!

Degritter is on limited sale with -16% discount on IndieGoGo. 8 days left to purchase the machine. Shipment will be in September due to long lead time from the chassis manufacturer. We will not accept further orders after the mentioned deadline and will concentrate on production. New orders with higher retail prices will be taken in November this year.

Purchase Degritter here on IndieGoGo!

 

I get the feeling that the URCM (Ultrasonic Record Cleaning Machine) industry is lacking clear evidence based communication to existing and potential customers. Degritter will be trying to change that

I agree with you regarding this industry (and not limited to just US RCM either). Your efforts and candor are much appreciated.