You don’t have to wait for January 1st 2000 to celebrate the new millennium, because with the introduction of the Beyerdynamic’s MCD 100 cardioid digital microphone, the new millennium is here today.

Digital Microphone?

Almost. There is still a condenser capsule that moves proportionally to sound pressure variations and serves as the transducer between acoustic and electrical energy. That is where the analog part stops. Immediately the internal 24-bit converter takes over and converts the analog motion of the capsule to digital numbers that are spewed forth from the XLR connector.

Because there is virtually no signal path length for the analog signal, there is never any time for the addition of circuit noise or induced hum from nearby cables. An AES cable is connected from the microphone to its power supply. This is a special power supply that provides phantom power over the digital cable to the microphone. The power supply also provides a gain adjustment control. The level is changed by bit shifting the 24-bit signal from the microphone. If you are recording to a 16-bit device, you can shift the bits so that you can use detail information of the 24-bit signal instead of chopping it off.

The power supply I used was the MPD 200, which will power and control two digital microphones. Each microphone is connected to the power supply individually and their internal clocks are synchronized by the power supply. The output of the power supply is one AES connection. The left microphone is sent on AES channel one and the right microphone is sent on AES channel two. If you only have one microphone connected, the signal appears on both AES channels. The cable from the power supply must also be an AES cable. There are two additional BNC connectors on the power supply for word clock in and out. If the microphone is the primary source, such as a direct connection to a DAT machine, then the sample rate defaults to 48kHz and the digital AES signal supplies the clock information. If you need to supply word clock to another power supply or additional gear, then word clock out connection will provide those signals. If you will be connecting the microphone to a digital system that needs to be the master, then your word clock (32k-48k) should be connected to the word clock input on the power supply. The microphone continues to operate at 48kHz, while the MPD 200’s internal sample rate converter slaves to the word clock in. To operate the microphone as a slave, however, you must open the power supply and change an internal jumper. There is no external switch.

There are other power supplies available for one to eight microphones, and they all can be cascaded together. The MPD 800 provides metering and gain control for up to eight microphones, and has a built-in TDIF and ADAT interface for direct connection to those devices. If you have a digital console that provides "digital phantom power, then you will not need the individual power supplies, but you must have a sample rate converter on the microphone input. There are also suspension mounts and pop filters available from Beyerdynamic.

Customize Your Microphone

Located inside the microphone itself is a DSP for tailoring curves to fit your needs. If you use one microphone for a particular purpose all of the time, then Beyerdynamic can custom program the DSP to include the filter of your choice. There are some situations where there would be a big advantage to having a microphone ready to go with built-in eq curves. (You can have multiple EEPROMS programmed and change them in the field.)


The Set Up

The first thing I had to do was find some long AES cables. I actually went against my better judgement and tried a long mic cable, but it didn’t work. After I got the right cables, everything worked perfectly. I wanted to record directly into ProTools as a 24-bit file. The ProTools was word clock slaved to, and SMPTE chasing along with a Sony 3348 digital 48 track. I ran a BNC cable to the MPD 200 power supply for word clock, and flipped the internal switch to "slave." I connected another AES cable from the power supply to the microphone itself. I powered up everything put on my headphones. The meters showed nothing and I heard nothing. I sent someone out to the studio to check my connections, and when he opened the door to the studio the sound almost blew my headphones off my head. What I was actually (not) hearing was the absolute dead quiet of the digital microphone. It made the mic I use with the big heat sink sound like a raging wildfire in comparison.

Yes, But How Does It Sound?

Well, I’m sorry, but I spent so much time talking about technical stuff that I don’t have room to cover the actual use of the microphone (just kidding.)

Remember the first time you recorded something digitally after suffering with the tape hiss of analog? Remember the clear noiseless background to your mixes? Well that was my initial response. I wasn’t hearing the microphone, I was hearing the piano, or acoustic guitar, or vocal as if there were no microphone. No tubes with rattling filaments, no sputtering FETs, no rustling phantom power noise from marginal connections or someone stepping on a punky mic cable. The smooth frequency response and warm low end were pleasing. The highs were crystal clear. The sound from just one microphone was three-dimensional. It had depth. You could tell exactly how far the instrument was from the microphone without looking.

My first impression left me in a state of too-good-to-be-true-ness. I kept the microphone for two months and used it on everything that moved. Pianos, acoustic guitars, vocals, percussion, drum overhead, harp, zythrwingle and surdo. The MCD 100 is the closest you can get to recording everything directly into a digital recorder without using a microphone. I’m hooked.

Conclusion

I only had one microphone for the review. I can’t wait to hear what a stereo pair of MCD 100s sounds like. The only draw backs to owning an MCD 100 is the additional investment in AES cables, and the fact that you have to run them through the door, unless the studio where you work had the foresight to run AES wiring to the mic panels. Don’t forget that you have to open the power supply to use the mic in slave mode. If you don’t change the jumper or run the MCD 100 through a sample rate converter, then you will end up with digital clicks where you don’t want them.

One last thing. If you figure out how much you are going to save on expensive mic preamps, your new MCD 100 will effectively be FREE. Tell your spouse to call me. I’ll explain it.