Panasonic wm-61a capsules
Most modern preamps that supply 48V phantom power do so through two 6.81K 1% resistors. Specifically two questions: “Why are you connecting the “+” on the capsule to Pin 3 on the XLR, which is the negative input” and, “I wired the XLR up and there is 48 volts on the resistor, I’m not connecting that to my capsule!”. I had multiple questions on how this worked after the Sound Sleuth build. It needs to be electrolytic and rated for above 48V. Anything between 1 and 10uF should work fine. I kept the capacitor value the same at 3.3uF. The original circuit used a 147K resistor and that is what we are using with the JLI-61A replacement. His joke to me is that he is good with ones and zero’s but not so good with things in-between. He now runs a company VVAudio that does ambisonic sound field processing. He extrapolated out for 48 volt phantom power and stumbled on a what is arguably the simplest way to do this. He said he started from the data sheet that shows a single resistor and capacitor but for 2-10 VDC. I caught up with him on this and asked him how he came up with it. This circuit was originally published by David McGriffy. The value is selected to match the FET internal to the capsule, usually by experimentation. This capsule contains in internal FET so the electronics are the same as in the previous Instructable with one crucial change: The value of the resistor in the P48 version.
#Panasonic wm 61a capsules professional
To interface the capsule to a recording device we have two options, a 3.5mm jack for small recorders and cameras, or an XLR jack for professional recorders. We are going to use some thin card stock to space the capsule. That number comes out of a Patent from 1982 for this concept as a product. Specifically we want it less than 1/16th of an inch. It turns out spacing isn’t super critical but should be as small as practical. He used a screw mechanism to adjust the spacing between the capsule and the flat surface. In 1978 Ken Wahrenbrock built a prototype of a stand alone Pressure Zone Microphone. There was a product made called the “Stage Mouse” that you could put a small diaphragm mic in and it would hold it close to the floor. Before they were specifically built, audio engineers used to place microphones close to walls and floors to achieve this. They were used a lot to capture drums by placing either one in the middle of the studio floor in front of the drums are a pair with the kick at the center of an eight to ten foot triangle. Well, that may not be exactly what happened but it makes a good story. Urban legend has it a microphone fell out of its stand ending up on the floor in front of drum kit and everyone in the control room immediately knew they had something great.
They work by having a small microphone very close to a flat surface. PZM or Pressure Zone Microphone is actually more of a technique than a product. I’m not actually sure when I lost, it but I no longer know where it is! So after doing a little research, I decided to build a few of them and this instructable will show you how you can too. It was very cool and I used it for years. The first microphone I bought in my youth was a Radio Shack PZM microphone. It also has the correct capsule gap designed in. I really want to thank Tom for doing this. Glue the assembled capsule holder to the acrylic base and clamp in place until dry.Hold the two pieces together with some rubber bands.I used a blob on top on the capsule to lock it into place. Glue and glue the two pieces together using E6000 glue.Press the wire into the little clips to hold it in place.Solder the Mogami wire to the capsule per the original instructable.The photo's show the new assembly process, which is much simpler! It is designed in two pieces with little clips on one side to hold the Mogami wire in place after you place the capsule in the hole. I am updating this instructable based on Tom Benedict creating a quite awesome little capsule holder for the JLI microphone capsule.