OT: microphones

[Brian Marshall]

I have a CAD E100 condenser microphone that i like quite a bit... In the last year or so it has developed a persistant popping sound.  totally random, but always there.  It also appears to be feeding out some DC.  my mixer shows input even when there is none.

Anyone have any idea what the problem is, or how to fix it?

I have no interest in paying someone to fix it.  I could probably buy a used one for what it would cost just to have someone look at it......  If i could find a schematic that would be cool too.

Brian

[Gus]

Is that the cad that takes two 9v batterys and is shaped like a flat rectangle?  Was it used around a drummer that might have hit it???

If it is

  The screws around the "edge" and the front and back will allow you to open it up.   Sometimes the back grill gets bent inward.  The electric element wires can touch the the back screen causing pops etc.  The capsule is mounted in an elastic shock mount.  I have "fixed" the grill and placed small pieces of tape on the solder connections.  I have worked two that had this problem.  If it is the microphone I think it is.



 I would also check the solder connections if you open it up.  IIRC the circuit is a fet phase inverter going to a 2 pnp output drive circuit.

[Brian Marshall]

that is the mic..
i already have it taken apart... i though for sure it was the balanced connector, but it isnt.  

It has been arround drummers, but was always on the kick drum... never a direct hit.  

One thing i noticed was that one of the batteries only had a 5v charge... not sure if the battery is bad, or if the mic hasnt been charging it.

Brian

[Brian Marshall]

yes, i'm afraid this microphone is probably trash... i will try replacing the batteries, but i dont think that is the problem.  i think it has been in too many kick drums.

[Johan]

I know that mic..   ...I had one a few years back...mine did the same thing when the batterys were low...just leave it on with the phantompower on from the mixer over night and that will charge the batteries...could ofcourse be something else, but that allways worked with mine....

Johan

[Brian Marshall]

That is exactly what i did... we'll see when i get home tonight.

[Peter Snowberg]

If you have a 9V that is only putting out 5V after recharging, the battery is almost surely dead. You can only recharge a rechargeable battery so many times before it fails.

If these are NiCd batteries, they fail in a way that lowers the internal resistance. If the batteries are being charged in series, this will make the 2nd battery fail too. I would replace both of them before the mic.

-Peter