Is My Mic Dead? No signal from the front; only the back!

[The Silent Coup]

Hello,

I have owned an SE Electronics Z3300A for about the past 5 years or so (or more - cant remember!), and it has always worked flawlessly. However, a couple of days ago, it seems to have developed a fault. It appears only the 'backside' of the mic is working. When using cardioid, no signal is present when speaking into the front of the mic, and only signal is present when speaking into the back using omni or figure-of-8.

This suggests that it is a problem with the diaphragm, rather than anything in the output staging, as there is still signal coming from the device. If so, does is mean the end of the mic? (I have been informed that once the diaphragm goes, that is it! Any cost to replace the diaphragm outweighs the cost of buying a new mic). Or is it possible to fix it?

Any help will be greatly appreciated.

Thanks

Chris

[Hugh Robjohns]

It could be a failed diaphragm, although that is unusual. Could also be a broken pattern selector switch which is probably more likely.

I'd contact se directly to see what they suggest.

H

[James Perrett]

Almost certainly repairable and, as Hugh says, the pattern selector switch or a capsule connection is the most likely problem. The usual symptom of a bad capsule is noise but capsules can often be repaired or replaced so no need to throw the mic away.

James.

[The Silent Coup]

Thanks chaps,

I sent an email to SE's support desk, and they were only helpful in trying to make a small raise through a part exchange deal for old SE mics, offering 50% off of any mic if i send it in. I guess this is still a good option if i cannot find anyway of fixing it myself or via an electronic engineer, but id rather try first before throwing in the towel.

On the matter of it being a faulty selector switch, i will investigate this again, as my focus was on the diaphragm and xlr connector at the bottom (although as mentioned, if there is still signal from it, it is unlikely to be a problem here).

I shall let you know the outcome!

Thanks

Chris

[James Perrett]

Hopefully our resident mic repair expert will see this thread and give some advice - although I know he's very busy at the moment so be patient.

James.

[SimonZ]

As Hugh and James have said, diaphragm failure is reasonably unlikely.
The symptoms you describe should be a simple fault.
The Z3300 has switched polarisation voltage to the rear diaphragm, fixed voltage to the front and signal picked from the backplates. (If I remember right, I'll check).
Lack of voltage to the front diaphragm would give you cardioid, nothing, cardioid (polarity reversed) when speaking into the back of the mic for the three pattern options, so the switch is probably OK.
My guess would be the wire from the front diaphragm is loose at the screw terminal in the centre of the capsule or it has become detached where it meets the d.c. board. (Or a cracked joint there)

Chris, pm me and I can mail you photos of where to look if you need.

Fairly hopeful for an easy fix.