that's an interesting way to clean a capsule, what do you guys think about this?

[abbey road d enfer]

ultrasonic cleaning works by cavitation, that is, zero-pressure "negative" bubbles collapsing and exploding, giving local scrubbing action

@Jakob, Winston, living sounds, OK, I've been warned! I'll limit the use of US cleaner at PCB's only!

 

[Tubetec]

Interesting test with the Alu foil Jakob,
Thing is if you remove the oxide layer from aluminium it readily reacts with even air itself. Gold as we know doesnt tarnish or go dull  , of course thats no guarantee a sonic cleaner wont damage a precious capsule either, still would be interesting to test the theory.

I read somewhere the presence of a voltage on the foils of a capsule can in itself cause dust to become attracted,
for that reason I went with a similar arrangement to a U47 where the central electrode has the polarising volts applied with the front membrane connected to grid at or near 0V.  Interested to hear if anyone has noticed certain mics are more prone to contamination than others .

 

[Ethan]

Years ago I did something similar with a gunked up capsule in a cheap mic that I didn't care much about if I destroyed. Except:

1) I used a small aquarium filled with distilled water.
2) Connected a small air pump to LDPE piping and poked small holes through it with a safety pin
3) I coiled it around and held it together with a tie wrap then plugged the other end of the hose and submerged it in the tank.
4) Turned the air pump on and we now had small gentle aeration/agitation/bubbles.

I dunked the capsule in the center of the ring of tiny bubbles. It worked well!
But at the time I thought it was silly so I didn't share--in fear that someone like a "Klaus" might come along and write a dissertation on my idiotic method of destroying a capsule.  ;D

EDIT: If I were to redo it today I'd use a Y connector to pump air into both ends of the pipe "ring".

 

[Tubetec]

Interesting idea Ethan,
bubbles of air seem less likely to do damage than any kind of physical contact, even a fine brush .
Maybe C02 bubbles/water which is slightly acidic might be even more effective at scrubbing.
Preferably you want to avoid getting liquid behind the membrane, the surface to be cleaned need only sit just below the liquid as opposed to fully dunked 
By the sounds of it there's a pile of business out there cleaning capsules , a fool proof cleaning methodology with no chance of physical damage could be a real banker.

 

[bockaudio]

But at the time I thought it was silly so I didn't share--in fear that someone like a "Klaus" might come along and write a dissertation on my idiotic method of destroying a capsule.  ;D

I wouldn't worry about Klaus revealing his method.
Re: Dan Alexander: funny how reputations can change as one generation leaves and another takes it's place.

 

[Krackle]

HI All,

I took the plunge, and cleaned the capsule of a very abused and no longer used MXL 2003a using this flood the decks method.
perfect donor. Had seen this video some time ago, and i thought it was nuts..so it stuck in my head...
I searched for the video and found it here. thought I'd unearth this thread and share my result

I have to say that this rinse bath method worked very very well..
This capsule was pretty funky..not to the point where it was exhibiting drop outs or rushing, but funky.
After slow drying and testing the MXL i was confident enough to clean the Capsules on a 1984 U89 and a TLM 193...I bought the TLM 193 from a Rapper and the capsule majorly spittled..

Worked like a charm..im sort of stunned actually.

I didn't use a Gravy separator..
I used food grade kitchen sauce bottles..and modified the squirter by cutting it back a bit to get a larger hole so it wouldn't be as aggressive as a narrower, pointier stream of water. Worked great.

I dried all the mics with a small 50 watt halogen flood in a clip on lamp about 18 inches away pointed at the mics-which were standing up in tall drinking glasses...touched the metal of the capsule housing every once in a while to check temp..

Watching that video..the Gravy Separator seemed a bit loose and clumsy to hold..

 

[Whoops]

This is the Neumann Doc for capsule cleaning.

Just remember one really important thing, if you use a Brush you have to get the softer Brush you can find, only use a really soft small bush.
An then don't apply any pressure at all with the brush, don't scratch the diaphragm, almost don't brush it just touch it very lightly and slowly.
If you don't do this you will damaged the Gold sputtering on the membrane

 

[Krackle]

This is the Neumann Doc for capsule cleaning.

Just remember one really important thing, if you use a Brush you have to get the softer Brush you can find, only use a really soft small bush.
An then don't any pressure with the brush, don't scratch the diaphragm, almost don't brush it just touch it very lightly and slowly.
If you don't do this you will damaged the Gold sputtering on the membrane

Thanks Whoops..
Im leery of any brush on a capsule..A Sable artists brush would be the ticket but nevertheless..actually using a brush has been what's held me back in some way..fear

this flooding method worked so well though..

Interesting that in the Doc you linked, Neumann mentions that the K89 type capsule
doesn't show same, or, typical dirt symptoms due to being connected to 0 volts..
Too late though..obviously i cleaned 2 k89 capsules in this run..One was very nasty..the spittled TLM 193..like said, both now very clean and operating perfectly..thanks for the doc..