Linkwitz Mods On Panasonic WM61A Mic - Page 4

acceltemp · 14th February 2010, 08:51 PM

I use about a 1 cm of desoldering braid, spread out the strands at one end, and wrap around the aluminum case of the microphone. then slip on a piece of shrinkwrap and shrink down to hold the wires of the braid against the case. Because there are so many wires in the braid, at least one of them will make a good connection with the case.
Now I can solder to the other end of the braid without worrying about overheating the cartridge and without destroying the airseal by cutting away part of the case for soldering. Seems to work well, and most diy have desoldering braid and shrink wrap tubing.

basreflex · 25th February 2010, 10:27 AM

be aware that the Nfets in these capsules have diode from source to gate for biasing, and by nature of the nfet there are diodes from gate to source and drain. at low supply voltages that diode capacitance is the major attenuator and the main source of distortion due to the no linear voltage vs capacitance. for a constant gain keep the dc voltages always the same on the capsule.

teleman · 16th July 2010, 09:44 AM

You can actually buy braided grounding stocking from many elec.component suppliers. They're available from 2-4mm to really large diameters. a 8mm one should be just fine.

teleman · 11:21 AM

Here is a schematic og WM61 capsule wired for balanced input! The entire article can be found on

Suite101.com: Online Magazine and Writers' Network

PS:Please note that the "Caps" are drawn wrong,but the orientation is correct!

454Casull · 26th July 2010, 12:37 PM

Quote:

Originally Posted by teleman

Yes! Since the foil is conductive & adhesive on one side you'd only need to cut a small strip,peal off the protective layer & wrapp it just about 1mm sticking out of the capsule.Now when you bend the top of the foil it will cover the rim of the capsule as well. Then solder the wire to the 'sected ground trace & the foil covered case together as you would normally.

Isn't the adhesive side insulative?

bigwill · 26th July 2010, 12:52 PM

Quote:

Originally Posted by 454Casull

Isn't the adhesive side insulative?

It seems to conduct pretty well, which is a useful property!

teleman · 01:25 PM

Quote:

Originally Posted by 454Casull

Isn't the adhesive side insulative?

No!...it's conductive adhesive & hence conducts very well indeed! I've wired 10 capsules without destroying any of them!

I bought this conductive-adhesive-copper foil on the E-Bay, of course these are available as non conductive too.So make sure that you order/buy only the one with the conductive adhesive on the back.

I gather,these foils can be bought from "home gardening stores"..too as these are used to protect plants & flowers from snails, by running weak electricity through them!

Speedskater · 26th July 2010, 08:55 PM

conductive-adhesive-copper foil is also available at stained-glass hobby stores.

teleman · 07:43 AM

Here is a link which I think would be very useful to all those who want to know more about the inner workings of an electret mic.

http//www.openmusiclabs/learning/sensors/electret microphones

teleman · 26th June 2012, 10:43 AM

Here are 4 different methods of biasing an electret mic in the source follower configuration.

26th July 2010, 08:55 PM	#38
Speedskater diyAudio Member Join Date: Sep 2002 Location: Lakewood, Ohio	conductive-adhesive-copper foil is also available at stained-glass hobby stores. __________________ Kevin

25th June 2012, 07:35 AM	#39
teleman diyAudio Member Join Date: Jul 2008	THE SECRET LIFE OF ELECTRET MICROPHONES! Here is a link which I think would be very useful to all those who want to know more about the inner workings of an electret mic. http//www.openmusiclabs/learning/sensors/electret microphones Last edited by teleman; 25th June 2012 at 07:43 AM.

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14th February 2010, 08:51 PM	#31
acceltemp diyAudio Member Join Date: Feb 2010	I use about a 1 cm of desoldering braid, spread out the strands at one end, and wrap around the aluminum case of the microphone. then slip on a piece of shrinkwrap and shrink down to hold the wires of the braid against the case. Because there are so many wires in the braid, at least one of them will make a good connection with the case. Now I can solder to the other end of the braid without worrying about overheating the cartridge and without destroying the airseal by cutting away part of the case for soldering. Seems to work well, and most diy have desoldering braid and shrink wrap tubing.

25th February 2010, 10:27 AM	#32
basreflex diyAudio Member Join Date: Oct 2007	be aware that the Nfets in these capsules have diode from source to gate for biasing, and by nature of the nfet there are diodes from gate to source and drain. at low supply voltages that diode capacitance is the major attenuator and the main source of distortion due to the no linear voltage vs capacitance. for a constant gain keep the dc voltages always the same on the capsule.

16th July 2010, 09:44 AM	#33
teleman diyAudio Member Join Date: Jul 2008	You can actually buy braided grounding stocking from many elec.component suppliers. They're available from 2-4mm to really large diameters. a 8mm one should be just fine.