AKG D12 repair attempt...

[strangeandbouncy]

I saw one(D30) with it's cover of a cople of months ago, and I am sure the two capsules were the same . . .

 

[Schmilsson]

Ok, I just realized how the d19 is constructed and how royally fucked I really am.  ;D

 

[clintrubber]

Nice thread, thanks for the info-sharing !  
Now let's hope the generator-trick works for my bass-shy D12 as well.

Apart from that and assuming that trick does the trick, anybody a suggestion how to cleanup the dirty inside of the mesh-cage ? (see attached pic)

(I need to fix the surround as well but got already a suggestion for that.)

Bye,

 Peter

 

[abbey road d enfer]

Apart from that and assuming that trick does the trick, anybody a suggestion how to cleanup the dirty inside of the mesh-cage ? (see attached pic)

Bye,

 Peter

Since it's constituted mainly of iron oxide (commonly referred to as rust), use a phosphoric acid-based rust cleaner. Just google for it, it is available from most car and diy shops. Don't be afraid by the concept of using an acid product on your cherished microphone. Phosphoric acid dissolves rust and creates a very thin protective layer of iron phosphate. Apply product with a brush, let it react for 15 minutes, rinse and repeat if necessary. Most suppliers of this type of product offer a passivating product. The use of such a product is justified only for large parts that cannot be rinsed properly. For your mic basket, rinsing under the tap for 30 seconds is enough to passivate.

 

[MagnetoSound]

You can also try Alka-Seltzer: http://www.videojug.com/film/how-to-remove-rust-from-small-objects

... or electrolysis: http://www.videojug.com/film/how-to-remove-rust


BTW, I don't expect that any of these methods are likely to save the wind-resistant flock lining of your grille - but let us know.

 

[rodabod]

Speaking of D19, I'm trying to get mine working...

I suspect those hair thin coil wires to be the problem. Any ideas or suggestions?

Start by measuring coil continuity at the socket (there isn't a transformer in the single-impedance models).

 

[clintrubber]

Thanks all for the tips !

BTW, I don't expect that any of these methods are likely to save the wind-resistant flock lining of your grille - but let us know.

The funny thing is, the grille looks decent on the outside, the uglyness is just on the inside. But it gives the impression that it sort of congests the small openings, not sure.

Assuming that the flock will indeed disappear, how important would it be for a bass-mic that will be used indoors 99% of the time ?  It will see some moving air of course, since I'm after that stentorian bass as well 

Bye,

  Peter

 

[MagnetoSound]

Assuming that the flock will indeed disappear, how important would it be for a bass-mic that will be used indoors 99% of the time ?

LOL, I asked myself that as I was posting earlier.

Dunno! I doubt it will be a problem on bass guitar, on bass drum I guess it might, if used outside and in front of the drum where the wind is strong ... close to the head, perhaps not.

 

[emrr]

good work gentlemen; another set of techniques for the files. 

 

[clintrubber]

On the topic of D12... D12E.... has anyone ever seen a clone/copy that has
the big monster-capsule-engine-motor-capzilla inside ?

I read about clones that look like a real one from the outside,
but simply have something else inside.

There happens to be a certain 'Electric Sound' copy for sale here, but can't imagine
the clonists took the trouble to go Jules Verne and all.
I know I should pass on this, but OK... 

I can obviously test it, but he won't let me open it I expect. If it has the sound
then it has the sound, but that'd require better test-possibilities than doing a bit
of pfah-pfah over there.


Thanks,

  Peter

 

[emrr]

I've also seen at least one D12 body with a ribbon motor hacked into it.  Supposedly came out of USSR. 

 

[rodabod]

There is one Italian company that made a clone. It wouldn't probably trust it to be similar though.

 

[clintrubber]

Can't imagine the 'local copy' has the Big Thing inside...

Hmm, if the price was lower I might go for it to get a new unbroken surround 

Bye,

  Peter

 

[s2udio]

-Would this be worth photographing in case it helps anyone?

Keith

Oh yes please.............!!!
unless i missed the boat ?
Just bagged one on evil bay( for a few peanuts !) with said symtoms,and a healthy reading of the voice coil
........275 ohms ?
Attempt at repair to be made using Roddys method.........shortly
ps Will photo the process,and post results (if sucessfull.........unless of course Keith you already have  )
any more tips ?

 

[biasply]

Really glad I found this thread (Thanks to Roddy)....
Have an old Echolette D12 that I thought needed a new capsule due to tinniness, but now I have an option to try....
Thanks!! this forum is simply amazing...
Steve.

 

[biasply]

Okay so I got the thing opened and the 6 screws loosened, but I can't get the diaphragm to move around the way it sounds like it should?  Also the ring held by the 6 screws is still quite fixed.... any thoughts?

Steve.

 

[Martin B. Kantola]

So reading this thread I remembered having a bass-less D12 motor somewhere. And yesterday there was suddenly a little time to hook it up to the trusty old and green B&K all-tube tone generator. The problem was very obvious, terrible buzzing especially at any lower frequency sounds. So I kept the frequency at around 100Hz at a reasonable level, and started loosening  the screws that hold the diaphragm. Didn't take me too long to find a position where the buzz was minimal, but the trick was to get all screws tightened while maintaining that position. The gap seems pretty narrow. Used a bit of drum head tuning method, plugged in the mike and SUCCESS! Although I need to test it on a real kick too, but happy happy joy joy!

My sincere thanks, have probably had this nonworking microphone for 20 years...!

;D

Martin

 

[SSLtech]

MARTIN!

-Good to 'see' you again!

I was thinking about our mutual acquaintance over the last day or two... (of course). -I hope all is well.

...and I'm glad that my little 'voyage of discovery' has benefited you also! -I think this should be made a 'sticky' or something... or maybe we should just keep quiet about it, buy up some old lifeless D-12's and make some money! 

Keith

 

[s2udio]

Just comleted a complete stripdown to capsule level (this one also suffering from moisture damage),and didnt respond to well to just loosening screws
and sweeping on the signal gen ....30-5k.
So had to............ Bite the Bullet and strip her down .......  ohhhhh...................Tried it out a few hours ago
Yeh hah !!....thanks of course to all here....
Lots of capsule stripdown photos available .........If ok will put them up with a basic rundown of the process  ;D

 

[KarlH]

yes please, more photos of the process.
I'm girding my loins and looking for the time to fix one here.

big thanks to keef for going where no man has gone before.

karl