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General Discussions => Brewery => Topic started by: pucho812 on November 22, 2020, 01:37:24 AM

Title: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: pucho812 on November 22, 2020, 01:37:24 AM
anyone have a thought on this?

https://www.youtube.com/watch?v=Zhhx6Fgh1z8 (https://www.youtube.com/watch?v=Zhhx6Fgh1z8)
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: abbey road d enfer on November 22, 2020, 10:12:21 AM
Distilled water supposedly doesn't leave any residue, and none of the materials constituting the capsule absorbs water, so it should be adequate.
The endemic problem with capsules and humidiy is that dust and particles absorb water and thus result in undesirable conduction. As long as cleaning with distilled water gets rid of dust and particles, and the capsule is thoroughly dried, it makes sense.
For PVC diaphragms, which absorb water., it could be debated.
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: Gus on November 22, 2020, 12:42:22 PM
Did you ever look at the back of some older u87 capsules?

Take a look, what do you see?

Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: pucho812 on November 22, 2020, 01:24:01 PM
Did you ever look at the back of some older u87 capsules?

Take a look, what do you see?

Which part, a perforated pressure hole as described by klaus heyne or the sputtering coming off? I will admint it’s been a while since I did anything with a u87 other then use it
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: pucho812 on November 22, 2020, 07:12:46 PM
Another recommendation was off access compressed air 😬
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: valco on November 24, 2020, 08:54:28 AM
I´ve tried this method a couple of times with great results on a couple of Neumann u87´s and an old schoeps cm61 i´ve had troubles with for ages
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: living sounds on November 24, 2020, 09:18:46 AM
Another recommendation was off access compressed air 😬


I once managed to destroy a tweeter while dust cleaning with an air compressor... A capsule would be ripped to shreds. (I know you were not recommending it)
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: Pip on November 24, 2020, 09:31:23 AM
As long as you give it a really good long time to truly dry out before powering up this is the best safest way. By the way the person in that video is one of the most trusted gear dealers I know of, he has been involved in the music gear biz for decades! I have purchased some great kit from him over the years.
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: Tubetec on November 24, 2020, 06:46:39 PM
I have seen compressed air used to clear out the gap on the pole pieces of a PA compression driver before a new diaphragm was fitted , someone poured a pint into the throat of the horn apparently , worked good as new after.
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: pucho812 on November 24, 2020, 07:08:46 PM
As long as you give it a really good long time to truly dry out before powering up this is the best safest way. By the way the person in that video is one of the most trusted gear dealers I know of, he has been involved in the music gear biz for decades! I have purchased some great kit from him over the years.

Yeah Dan is great for sure and I wouldn’t doubt him. But always good to get a second opinion especially when it comes  capsule cleaning. I got a few that need it but with the mic guys in high demand, might as well handle that for our studio mics, it’s just one more tool in the box to have.
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: Tubetec on November 24, 2020, 07:54:18 PM
You are a truly unstoppable force in your quest for knowledge Pucho ,

I wonder how would a sonic cleaner do at the job of cleaning mic capsules ,or maybe even driving the capsule itself at some high frequency while submerged in the solvent , you could always test it out on a 50 buck Chinese lucky bag mic , or a capsule already beyond repair .
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: pucho812 on November 24, 2020, 09:00:35 PM
You are a truly unstoppable force in your quest for knowledge Pucho ,

I wonder how would a sonic cleaner do at the job of cleaning mic capsules ,or maybe even driving the capsule itself at some high frequency while submerged in the solvent , you could always test it out on a 50 buck Chinese lucky bag mic , or a capsule already beyond repair .

It's all based on need. in this case,  I would live to just drop mic off at one of the local mic guys, but everyone else is doing that and there is long cue. Since the studio needs it right way, later crack on and get it done.
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: living sounds on November 24, 2020, 09:43:16 PM

I wonder how would a sonic cleaner do at the job of cleaning mic capsules ,or maybe even driving the capsule itself at some high frequency while submerged in the solvent , you could always test it out on a 50 buck Chinese lucky bag mic , or a capsule already beyond repair .

I've destroyed quality sunglasses (Oakley) with a supersonic cleaner. Knobs and fader caps I put in there had a different texture afterwards.

I would never subject a mic capsule diaphragm to this.

Solvents may destroy the adhesive glue that keeps the diaphragm in place.

Rinsing with aquadest looks like the best option to me.
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: bluebird on November 25, 2020, 01:51:24 AM
If your iffy about dunking the whole thing in, just use the solution but take a Q-tip and pull the tip apart to make a mini mop so to speak. Dip that in the solution and brush the capsule with it. Make sure not to hit the capsule with the stick part. Just mop the solution around, then let dry. Its softer and more giving than a brush. I've done it many many times and never messed up a capsule. It was taught to me by an old studio tech who is not with us anymore. The knowledge lives on though!
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: Winston O'Boogie on November 25, 2020, 03:00:33 AM
I know Dan, but didn't know this technique, thanks for posting Pucho
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: Tubetec on November 25, 2020, 06:15:04 AM
Ive cleaned one U87 that the owner made a botched attempt at cleaning and damaged the front surface of the capsule . After using the standard method same as shown in the video , a very soft paint brush ,squirrel hair most likely and purified water as the solvent. I ended up flipping the capsule back to front . Im not sure if frequency response was effected by reversing the capsule  but it worked without crackling hiss and spitting sounds afterwards, my guess is in the cardioid position damage to the unconnected back side didnt matter .
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: abbey road d enfer on November 25, 2020, 07:03:17 AM
I've destroyed quality sunglasses (Oakley) with a supersonic cleaner. Knobs and fader caps I put in there had a different texture afterwards.
I believe it's the solvent the culprit, not the ultra sounds. What did you use?
I intend to buy a supersonic cleaner and read/watched many tuts; it looks like isopropanol in distilled water is harmless to most plastics; again I wouldn't use it with PVC.
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: living sounds on November 25, 2020, 07:24:46 AM
I believe it's the solvent the culprit, not the ultra sounds. What did you use?
I intend to buy a supersonic cleaner and read/watched many tuts; it looks like isopropanol in distilled water is harmless to most plastics; again I wouldn't use it with PVC.

Just water and a little bit of dish detergent, same as I use for hand cleaning sunglasses. Those Oakley "glasses" were a multilayer composite of materials, and at least one layer started to peel of.

Isopropanyl in itself is indeed harmless to most plastics, but an ultrasonic cleaner can really put a strain on materials. And the glue used to bond the diaphragm to the capsule might react with the isopropanyl.

I cleaned all the really grimy fader caps of my current console by soaking them for a few days in cold water and dish detergent. They look good as new and the markings stayed on. On my previous console I cleaned them in an ultrasonic cleaner, which was quicker, but the texture got rougher - and I had to re-draw the markings by hand.
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: Winston O'Boogie on November 26, 2020, 03:32:27 AM
I've cleaned many vintage audio bits and bobs with an ultrasonic, I add a little industrial de-greasing solution.   It works great on dirty boards, jack fields, and switches etc., but I've made the mistake of cleaning some panels, on a few of which the ultrasonic lifted off the paint.

I don't think I'd risk a capsule in one myself unless it was as an experiment that involved using a dispensable capsule. 
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: gyraf on November 26, 2020, 04:58:22 AM
try putting a very thin piece of aluminum foil in ultrasonic cleaner - like the type used for ribbon mics. Give it 30 seconds, and when you take it up, you'll notice it has turned translucent. Look closely, and there's literally thousands of very-small holes punched in the foil.

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

TL:DR - ..don't use for anything you wouldn't clean with a toothbrush..

As for Dan's method - was it almost anyone else, I'd be worried. But if that guy tells you he gets consistent good results like this, I'd have no problem trusting him. He, if anyone, has been around for a while  8)

/Jakob E.
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: abbey road d enfer on November 26, 2020, 05:12:14 AM
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!
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: Tubetec on November 26, 2020, 08:04:05 AM
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 .
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: Ethan on November 28, 2020, 08:10:52 AM
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".
Title: Re: that's an interesting way to clean a capsule, what do you guys think about this?
Post by: Tubetec on November 28, 2020, 07:24:47 PM
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  :D
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.