Topic: AT-853 Bare capsules and DIY connector + BB

[margilca]

Hello,
I just got a couple of AT853 cardioid bare capsules from SP (AT853C-ELE) and I just want to start
experimenting with them. My aim is to build a connector and a battery box, from a previous post
I decided to use the following schema:
               --------------||---------------------------hot--- (left)
               |           2.2 microfarad
from left mic  |           input capacitor
               |
---hot-------- +----10k ohm-- "+"
                               \
---ground----------------------)---+--------------------shield-----
                               /   |
---hot-------- +----10k ohm-- "+"  "-"
               |    resistor   9 volt
from right mic |               battery
               |
               --------------||---------------------------hot--- (right)
                           1 microfarad
                           input capacitor

Now my issue is how to identify pins on the caps.
I assume the following desgination:
1) gold center pin >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> HOT
2) bolt shaped contact that surround the above gold pin >>>>>>>>>>>  GROUND
3) shaped contact near the case >>>>>>>>>>>>>>>>>>>>>>>>>> SHIELD
In my opinion I will also have to short pins 2 and 3 together.
Any idea or suggestion if the above is correct ?
Thanks in advance
Margilca

[poorlyconditioned]

Hello,
I just got a couple of AT853 cardioid bare capsules from SP (AT853C-ELE) and I just want to start
experimenting with them. My aim is to build a connector and a battery box, from a previous post
I decided to use the following schema:
               --------------||---------------------------hot--- (left)
               |           2.2 microfarad
from left mic  |           input capacitor
               |
---hot-------- +----10k ohm-- "+"
                               \
---ground----------------------)---+--------------------shield-----
                               /   |
---hot-------- +----10k ohm-- "+"  "-"
               |    resistor   9 volt
from right mic |               battery
               |
               --------------||---------------------------hot--- (right)
                           1 microfarad
                           input capacitor

Now my issue is how to identify pins on the caps.
I assume the following desgination:
1) gold center pin >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> HOT
2) bolt shaped contact that surround the above gold pin >>>>>>>>>>>  GROUND
3) shaped contact near the case >>>>>>>>>>>>>>>>>>>>>>>>>> SHIELD
In my opinion I will also have to short pins 2 and 3 together.
Any idea or suggestion if the above is correct ?
Thanks in advance
Margilca

*DO NOT* do this!!!

The bare capsules contain just the diaphram.  There is no FET inside.  The FET is in the *body* of the AT853 mic, so you need the capsule + body to do this.  Many other capsules, like Panasonic WM60/61, etc, have the necessary FET inside.

OK, If you have the AT853 body + capsule it works great.  I've done it.  Put +9V to the red wire, 0V (batt negative) to the shield, and run a 10K resistor between the yellow wire and shield.  (A 22K resistor works better, but 10K is OK.)  Take the audio off the yellow wire thru a 2.2uF capacitor.  This is called "3 wire" or "source follower" powering.  For more details of this, see the Yahoo group "micbuilders".

Enjoy...
  Richard

[margilca]

Ok,
Given that I have not damaged the diafragms, since I have tested the resistance with a common tester, and  if I should go ahead I will need a N type FET along with a diode to connect them all ?
Correct ?

[poorlyconditioned]

Ok,
Given that I have not damaged the diafragms, since I have tested the resistance with a common tester, and  if I should go ahead I will need a N type FET along with a diode to connect them all ?
Correct ?

Yes, you'll need an N-channel FET plus a few other components.  In particular, a 1GigOhm (yes 10e9 ohms!!!!) resistor.  Unless you're a true gear hacker, you'd best just get the mic bodies and connect them as I suggested.  Or use phantom adapters like most people here are using.  But if you want to become a gear hacker as well as a gear slut, come over to Micbuilders.  There is active discussion  of this among other projects.

  Richard