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Gear / Technical Help => Microphones & Setup => Topic started by: illconditioned on June 05, 2013, 12:39:45 AM

Title: New rig: Bruel & Kjaer measurement mics,
Post by: illconditioned on June 05, 2013, 12:39:45 AM: (http://Soundmann.com/MeasRig.jpg)
My new rig consists of:

Bruel & Kjaer 4145 (x2), B&K 4190 (1) -->
ACO Pacific 4012 preamp (x2) -->
ACO Pacific PS9200 200V dual channel PSU -->
Sony PCM-D50

4145 is a 1" measurement microphone, nickel diaphragm, 10-146dBA range. Vintage capsules, 1970 and 1974!
4190 is a 1/2" microphone, 14.6-146 dBA, more recent (1995?).

So far I'm just recording ambient (thunderstorms, water/waves, etc).

Richard
Title: Re: New rig: Bruel & Kjaer measurement mics,
Post by: page on June 05, 2013, 10:13:53 AM: I admit, that's sexy in a middle aged woman type way.
Title: Re: New rig: Bruel & Kjaer measurement mics,
Post by: illconditioned on June 05, 2013, 10:32:03 AM: Oh yeah, the white tape on the right mic is to hold the windscreen. I'm using DPA windscreens right now. Need something better for outdoor recording.

Richard
Title: Re: New rig: Bruel & Kjaer measurement mics,
Post by: Gutbucket on June 05, 2013, 10:44:56 AM: Very nice.

I was wondering about the white tape.

I'd think those will be just the ticket to measure wind turbine noise.
Title: Re: New rig: Bruel & Kjaer measurement mics,
Post by: dallman on June 05, 2013, 03:14:06 PM: It looks great Richard! I was tempted to open the package when it was in my hands, but couldn't bring myself to do it! You may want to post some samples...
Title: Re: New rig: Bruel & Kjaer measurement mics,
Post by: illconditioned on June 05, 2013, 04:34:44 PM: This is an "old school" system. The white box looks like something Niaint or Church would build. It takes a 9V battery and generates a 200V polarization voltage for the capsules. The "preamps" run from +28V. I have not opened them, but it is likely just a FET and maybe a line driver. The connectors are: ground, +200V, +28V, and signal out (unbalanced). Outputs are buffered by an opamp and output on a pair of BNC connectors. This can also work with electret capsules by removing the polarization signal.

I will report back when I get some measurements.

Richard
Title: Re: New rig: Bruel & Kjaer measurement mics,
Post by: page on June 05, 2013, 04:39:26 PM: Quote from: illconditioned on June 05, 2013, 04:34:44 PM
It takes a 9V battery and generates a 200V polarization voltage for the capsules.

damn.

I knew they were 200v caps, but that the box is powered by a 9v with some amperage is rad.
Title: Re: New rig: Bruel & Kjaer measurement mics,
Post by: illconditioned on June 05, 2013, 07:45:10 PM: Quote from: page on June 05, 2013, 04:39:26 PM
Quote from: illconditioned on June 05, 2013, 04:34:44 PM
It takes a 9V battery and generates a 200V polarization voltage for the capsules.

damn.

I knew they were 200v caps, but that the box is powered by a 9v with some amperage is rad.

Polarization uses almost no current. Ideally no current. The box in question runs for >40hrs on a single 9V battery. The output has a series 11MR resistor. Inside the preamp, there is something like a 10GR resistor.

Richard
Title: Re: New rig: Bruel & Kjaer measurement mics,
Post by: Bernd Out on June 05, 2013, 08:46:12 PM: Quote from: page on June 05, 2013, 10:13:53 AM

I admit, that's sexy in a middle aged ~~woman~~ yoga instructor (http://o4.aolcdn.com/dims-shared/dims3/PATCH/resize/273x203/http://hss-prod.hss.aol.com/hss/storage/patch/f45e1133995377bb59ba1ba1e2992f69) type way.

FTFY ;D