Humidity and condensor mics
DCMagnuson
condensor mics. I remember seeing some of you mention using silica gel to keep
the moisture levels down. I have a few questions:
1. Where can I buy this stuff? I guess I could buy 30 pairs of sneakers and
get the packet out of each box... but there must be an easier way ;)
2. If the silica gel comes unpackaged, what should I put it in to keep it out
of the mics? I assume I need some sort of very pourous bag.
3. How much do I need for each mic? I'll be putting them in ziplock bags to
seal them. Any adverse effects to uing ziplocks? (ie solvents released from
the plastic that will damage my mics, etc)
4. How often do you need to bake the silica to get the moisture out, and how
do you go about doing so?
Thanks in advance for your help
Dave Magnuson
Da...@HoohahRecords.com
http://members.aol.com/DCMagnuson
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David Josephson
>With the humidity levels rising, I've been thinking about protecting my
>condensor mics. I remember seeing some of you mention using silica gel to keep
>the moisture levels down. I have a few questions:
Humidity alone does not cause a problem. There must be some sort of ion
source, like dirt, salt, etc. on the insulating surface that becomes
conductive when it gets damp. Keep the internal parts of the mic clean
and it won't be a problem. When I visited the Schoeps plant recently, I
saw their humidity chamber -- a glass box with a layer of water kept warm,
so it was 95% or so humidity all the time. All mics leaving the plant are
left in there for 24 hours and tested for noise before and after. No
contamination, no noise.
If you have some mics that can't be cleaned and get noisy when damp, you need
the kind of gel with a built-in indicator that turns blue when it's dry and
pink when it's not. One source of this, if you live near a little airport,
is the plugs that are shipped in the spark plug holes of airplane engines
from the factory. There's about a tablespoon in each one.
>1. Where can I buy this stuff? I guess I could buy 30 pairs of sneakers and
>get the packet out of each box... but there must be an easier way ;)
>2. If the silica gel comes unpackaged, what should I put it in to keep it out
>of the mics? I assume I need some sort of very pourous bag.
Yes, or use the above mentioned screw-in cartridges.
>3. How much do I need for each mic? I'll be putting them in ziplock bags to
>seal them. Any adverse effects to uing ziplocks? (ie solvents released from
>the plastic that will damage my mics, etc)
Enough that the sealed volume is such that the gel can stay blue. If it
takes too many recharges of the gel to keep it blue, you need more gel.
>4. How often do you need to bake the silica to get the moisture out, and how
>do you go about doing so?
Depends on how humid the air is, and 150-180 degrees F oven again until the
crystals turn blue.
--
David Josephson / Josephson Engineering / San Jose CA / da...@josephson.com
Black Audio Devices
Hollywood. It worked well, but you have to be diligent and leave the
mic in the silica gel when it's not in use. I got the stuff from
Student Science Services in Burbank, CA. I think they'll do mail/phone
order, and you can get a number from directory assistance. I don't know
if they have a web site. They are also called Tri-Ess.
I used what's called "indicating" silica gel. When it needs to be
baked, it changes color.
Since the facility had the original leather tubes that the mics came in,
I put a bunch in the bottom and covered it with window screen to keep it
in place. I suggest a box of some sort if you don't have the original
case. Sprinkle a layer on the bottom, and cover it with some cloth or a
paper towel.
Good luck!
jaymz
my u47's have a packet in each case no problems w/midwest humidty
the nuemann pinboard discusses this alot
the simple remedy if you will is just warm them up
after an hour or so the moisture will be gone due to heat
this is the advice via nuemann
in tube land this works obviously
as for 48v mics?
you'd sort of think the same i guess
jaymz
JimKollens
the moisture levels down. >>
You can buy silica gel in boxes at most floral shops (such as Frank's). It is
used for drying flowers. I scoop it into Melitta coffee filters and fold it
down and staple it. Be careful not to get the dust on the outside of the
filter bag. Periodically, hold the bag up to a light. When it turns pink,
it's time for a 275 degree oven - good food for your mics! (I've heard you can
microwave the packets, but I personally never tried it)