Any condenser mic gurus?

[Munjibunga]

Well, I done got ripped off for the first time on CL, and it's my own danged fault. I bought a Rode NT-1A off a guy without trying it out. So I got it home and hooked it up, and it worked fine ... for about 10 seconds. Then I waited 30 seconds and it worked fine. For about 10 seconds.

I've pulled it apart, cleaned the contact pins, and the connections are fine. There's a circuit board in there with a bunch of caps and some resistors, and I couldn't see any obvious issues with them. The diaphragm looked fine, too. It just fades out and fades back in. Is it possible that the condenser is not holding a charge, or what?

So I called the guy a couple times, and he agreed to refund my money, but he was up in L.A. and wouldn't be back 'til after the first of the year. So I called him a couple days ago and ... you guessed it: his phone is no longer in service, and I don't know where he lives, so killing him is out.

Since I'm stuck with the danged thing, I might see if somebody can fix it, but they're so danged cheap, I guess I'd be better off buying a new one. But I don't want a new one, I want a great deal on a used one, like the deal I got on this one, only one that works.

So who knows why it might be behaving this way?

[lowfreq33]

What do you have supplying phantom power? Some condenser mics don't work properly with less than +48v, and some consumer/prosumer mixers don't deliver a full +48v.

[Munjibunga]

I was running it off my new Presonus 16.4.2. They guy admitted the mic was hinky after I told him about it. They advertise 48V phantom, and I only had the one mic connected.

[T-Bird]

Hi.

I'm no expert, but I did quite a bit of research when I first got the bright idea of rolling my own. (Hasn't materialized yet though ).

Sounds like the diaphgram charge doesn't hold, ie. the capsule either discharges because of a short, or the circuit overcharges the capsule until it discharges and cuts out and recharges it again.

Neither one is easily repairable, or even possible to diagnose with regular instruments.
One of the reasons that condenser mics aren't as popular DIY items they could be.

Rode NT's are one of those mics that are modded extensively though, so someone in DIY recording forums may have a solution for You.

Regards
Sam

[Dirk Diggler]

Phantom mics can get very picky with the power they are fed, I've seen that same thing when using a pre that claimed it sent 48v, upon testing it wasn't providing a full 48v.
Try plugging into a board or another pre, that would hands down point the issue to the mic.
I wouldn't imagine it would be a high cost repair, and I'm sure you got a good deal on the mic through CL so you still may end up ahead.
Good luck,
Dirk

[Munjibunga]

I troubleshot it a different way ... I plugged an identical mic into the board and it works fine. I just don't know if there's a local place that can fix mics. I've had good experiences with Rode's CS before, so I might start there.

[ggunn]

Sounds to me like it might have gotten wet.

[Munjibunga]

Originally Posted by ggunn

Sounds to me like it might have gotten wet.

Actually, I think it was dropped. I later noticed some minor deformation of the screen.

[sonic assassin]

well if theres nothing to be done, its not an incredible mic and hopefully you didnt drop a ton of money on it.

the phantom power generator thing is out. ive used cheap power with a rode before.. no problem. its neumann that is picky.

ive never seen this happen, so its hard for me to speculate. although im very interested in the outcome.

[Munjibunga]

I think I'll find out how much it costs to repair it. I was reading another forum in which a guy said his NT-1A did this and he used a Shure SM-7B instead. I have two other NT-1As and an NT-1, and none have given me problems. I got a good deal on the mic.

[Munjibunga]

OK, I took it in to the shop today. I'm not overly optimistic, but maybe it'll have to go back to Rode and they'll refurbish it.