Topic: Sennheiser MKE-40 modding help needed

[udovdh]

Hello,

Who, aside from Sennheiser, might be able to remove any shorts between the wires at the mic capsule from a set of MKE40-4's?
Someone in Europe or USA? Or elsewhere?

Please advise of a workshop that does this job well.

Kind regards,
Udo

[illconditioned]

Talk to Church Audio.  He can diagnose/repair this kind of gear.


  Richard

[udovdh]

Talk to Church Audio.  He can diagnose/repair this kind of gear.

Thanks, any European shops? (closer to home...less hassle with customs taxes)

[John Willett]

Talk to Church Audio.  He can diagnose/repair this kind of gear.

Thanks, any European shops? (closer to home...less hassle with customs taxes)

If you are in the UK go to Martin Gathard at Sennheiser UK - best man for the job.

[DSatz]

Why would anyone want anyone but Sennheiser to service a Sennheiser microphone? When the manufacturer has a first-class service organization, that's the best choice unless there is a very definite reason to go elsewhere. This is all the more true when a problem affects the capsule or the circuitry that is connected directly to it.

I realize that there can be unusual circumstances. Your subject line mentions "modding," so perhaps someone was trying to do something interesting to the microphone and instead messed it up. That's a situation which the microphone manufacturers are very familiar with, since it occurs more often than some people might suppose when they start out on this road. Professional condenser microphones may look simple, but their manufacture--and thus their proper repair, or even proper reassembly after they've been taken apart--isn't always as simple as it may look.

It's no exaggeration to say that the better manufacturers have secrets in the capsule department which they don't put down on paper and don't divulge, for fear that their designs could some day be cloned. At least that's true for the central European manufacturers that I'm the most familiar with, one of which is now in the Sennheiser family. Even if you or I had all the original parts and the original drawings, without direct training and manufacturer-specific tools (and quite possibly years of practice), we almost certainly couldn't assemble a capsule so that it would sound exactly like one of theirs.

It's not a field for amateurs to play in unless they're prepared to discard their failures--which are more frequent than one might suppose--or at least to pay up to have their experiments rescued.

And by the way, the manufacturers are used to being contacted by desperate repair technicians who get in over their heads. Sometimes it's really not the technician's fault, and at least those people are honest enough to admit that they don't know what they should do next. It's the ones who can't admit it and instead, keep trying to barrel their way on through that sometimes cause the most damage.

--best regards

[illconditioned]

Why would anyone want anyone but Sennheiser to service a Sennheiser microphone? The manufacturer's service is the best choice unless there is a very definite reason to go elsewhere.

I realize that there can be unusual circumstances. Your subject line mentions "modding," so perhaps someone was trying to do something interesting to the microphone and instead messed it up. That's a situation which the microphone manufacturers are very familiar with, since it occurs more often than some people might suppose when they start out on this road. Professional condenser microphones may look simple, but their manufacture--and thus their proper repair, or even proper reassembly after they've been taken apart--isn't always as simple as it may look.

This is all the more true when a problem affects the capsule. It's no exaggeration to say that the manufacturers have secrets which they don't put down on paper and don't divulge, for fear that their designs could some day be cloned. At least that's true for the central European manufacturers that I'm the most familiar with, one of which is now in the Sennheiser family. Even if you had all the original parts and the original drawings, you almost certainly couldn't assemble a capsule so that it would sound exactly like one of theirs.

It's not a field for amateurs to play in, unless they're prepared to discard their failures--which are more frequent than one might suppose--or at least to pay up to have their experiments rescued.

--best regards

OK, I agree with that.  I certainly wouldn't recommend allowing a third party to repair an expensive mic.  On the other hand, fixing a cable (or modding) a $100 lav mic, is not a bad proposition.  I guess it wouldn't hurt to find Sennheiser service rates first, but if it turns out to be out of warrantee, or just too expensive, a third party person might be the best bet.


  Richard

[DSatz]

Richard, I understand your point but I'm suggesting that a distinction be drawn where the capsule and the components directly connected to it are concerned, as in this instance. In conventional, DC-polarized condenser microphones that part of the circuit operates at extremely high impedance (gigohms), and a microphone's noise and distortion levels can sometimes be raised merely by leaving a tiny spot of normal skin oil residue in the wrong place. Even the average trained electronics technician would not necessarily know how to do proper work in that type of circuit. And I'm saying that having been a professional hi-fi equipment repair person myself; it's a specialty area that requires a rather different way of looking at things from normal low-to-medium-impedance audio circuits. Familiar electronic components no longer behave in accustomed ways, and the usual operating assumptions often get turned on their heads.

Sennheiser MKH-series microphones use the variations in the capsule's capacitance to frequency-modulate an RF carrier. But then the circuitry connected to the capsule isn't the usual, straightforward linear current amplifier; instead, it's an RF detector, and it needs to be realigned if/when any of its parameters are changed. So the quiz question that I'm asking--and if you get the answer right, the value of the microphone will be preserved--is: Does your friend with a soldering iron know how Sennheiser aligns those circuits at the factory? Or do you even believe that he can intuitively find a better way to do it--one that the manufacturer hasn't been able to figure out in 40 years' experience of building and repairing their own products?

My own answer to that question will be something that I hope will be recognizable as a Groucho Marx reference. I used to be a reasonably competent audio repair technician, and I have a general idea of the procedures involved. But if I were going to buy a professional condenser microphone, I sure as hell wouldn't buy one that someone like me had ever done repair work on! To do it properly requires extremely specific practical knowledge, and there are more people who claim to have it than actually do have it.

--best regards

[John Willett]

DSatz has put this all very well and I do agree - always send a mic. back to the original manufacturer wherever possible.

I was actually over at FLEA microphones a couple of days ago, talking to them about their "clone" microphones.  It took them four years of dedicated work, plus purchasing special equipment to do it, to be able to understand and reproduce the capsule from the vintage C12 microphone.  Microphones are *not* simple things and there is a lot that most people do not understand.

Though, having said that, the original question was for the MKE 40 electret cardioid tie. mic and not the MKH 40 RF condenser mic..

But I would *still* send this to Sennheiser as a directional mic. and its housing have to be carefully assembled as all this effects the performance.


 

[udovdh]

Thanks for the discussion.
It's indeed about an MKE-type mic.
It's about removing one short at the capsule.
The mic itself is fully documented with drawings and even wiring schematics (for older variants of this type).
Email was sent to Church Audio.
Any other takers?

[DSatz]

Whoops--sorry I misread the microphone series (and it's even in the subject line of each message). That's what I get for posting while sleep-deprived. I hereby wish to take my earlier sermonizing down by 1.3 notches. But I would still say the same as I did, had this been a top-of-the-line microphone from a manufacturer with "old world" service.