Topic: what would cause a mic to loose sensitivity?

[Nick's Picks]

i've got these 4061's that were working fine.
I replaced the HUGE stereo mini jack on it w/one of mine, and since putting it back together one channel is about -12db from the other.
not very matched!
They were not like this before, and I have re-soldered that connection several times, making sure that there is good contact.

any suggestions?

[Chuck]

Moisture (sweat) is also a common problem with these microphones.

[Nick's Picks]

possibly the static discharge...but i'm not sure.
could have been.  I guess i'll have to send them to dpa for a once over after this flury of taping I have to do.

[Nick's Picks]

maybe...i'll report back after I try some other BBs i have

[Nick's Picks]

tried a known working battbox, same issue.
this one, however, has a sliding attenuator that allows me to level out the differrence.
bummer still.

suggestions?
probably need to contact dpa to get these spruced up.  they will shit when they see what i've done to them.

[Church-Audio]

Did you use a static free soldering station? Or just a regular soldering iron? If it was not static free you must have zapped the FET inside the capsule. One way to check this is to get a digital VOM with a diode check, attach the red lead to ground of the 3.5 mm jack and the black lead to the tip or ring of the connector. Measure the resistance and compare it with the known good one.
they should be the same if they are it is a static build up at the head of the mic or a partial short of the capsule try blowing on it with a cloth in front of your mouth to prevent moisture from getting on the mic capsule this may clear the debris from the capsule and get it back to working order.


Chris Church

tried a known working battbox, same issue.
this one, however, has a sliding attenuator that allows me to level out the differrence.
bummer still.

suggestions?
probably need to contact dpa to get these spruced up.  they will shit when they see what i've done to them.

[Nick's Picks]

Cool Chris...i'll give it a go.

DPA suggested rinsing the mic with distilled water and letting it dry.  They told me these things are moisture defiant, not prone.  they thrive on  sweaty head, as they were designed to.

static free soldering iron?
never heard of it.

[Church-Audio]

All good soldering irons are grounded and have 0% static energy at the tip cheaper 2 prong soldering irons can build up a static charge that can destroy a FET transistor like the ones inside electret mic capsules in the blink of an eye. A good tip pardon the pun for anyone wishing to solder mic capsules or connectors on mics ( same thing) to always make sure you use a grounded soldering iron with a three prong Edison plug or U ground as we call them here in Canada eh

The distilled or dematerialized water is a good idea try blowing on the mic first not like a tornado but a gentle gust this might clear up the debris from the head. If you try DM/DS water you must let it dry for at least a week, and make sure you take the response cap of the mic capsule. It will not hurt. All it takes is a small bit of conductive material to touch the mic capsule and short it out and you have a huge drop in sound levels.
I would hang the mic upside down capsule head facing towards the ground and just leave it alone for a week then check back and see how it worked. You can cover the mic head with a foam windscreen to prevent other debits from getting into the head. Then once its dry put the cap back on the mic head and give it a shot.

If you check the resistance like I mentioned in my previous post and they are way off from each other do not bother with the water. Try rechecking the soldering of the wires these DPA mics have fibers inside the wire for strength this same fiber if not burnt off with a match or lighter before soldering can result in increased resistance of the connection this will have a direct impact of the mics output (I have seen many a "dead" lav only need to be re-soldered because the fibers were not burnt off prior to soldering) let me know how this works out.



Chris Church
 

Cool Chris...i'll give it a go.

DPA suggested rinsing the mic with distilled water and letting it dry.  They told me these things are moisture defiant, not prone.  they thrive on  sweaty head, as they were designed to.

static free soldering iron?
never heard of it.

[Nick's Picks]

thanks again Chris...i'll check all that out.
my iron is a low end Weller, but still a good one.

I"ll see if i cant whip some life back into this sucka

[lbgspam]

Probably watching too much of the Oxygen network. 

hehe, loss of sensitivity...

[poorlyconditioned]

Did you check the obvious things?  That is, the connector?  Strip another short piece of the wire and see if there is a break somewhere.  Resolder a new connector on it (or connect with aligator clips).

Electret mics are (pretty) tough, so I would not suspect the mics themselves, unless they have really been abused.

  Richard