Core Sound — Denecke AD-20/Zefiro Inbox dual 20-bit Microphone Pre-Amp and 20-bit/44.1 A-to-D (Standalone)

The AD-20 was jointly developed by Zefiro Acoustics and Denecke Inc. and is the perfect addition to your current DAT deck, MiniDisk recorder or digital I/O card.

This compact, portable unit has two 20 bit Analog-to-Digital converters and dual low-noise microphone pre-amplifiers. Stereo gain is adjusted using individual gain pots for left and right. Dynamic range at minimum gain (+17dB) is 98dB. Maximum gain for full scale digital clipping is 70 dB (input at -47.5 dBu)

On the bottom of the AD-20 are the dual XLR balanced microphone inputs. We offer an optional cable to convert unbalanced 1/8" (3.5mm) stereo miniplugs (standard on our Core Sound microphones) to two XLRs.

On the side of the AD-20 are the dual gain pots, low battery indicator, coaxial S/PDIF output (1/8" miniphone jack), and optical S/PDIF output (Toslink jack).

A 9 Volt alkaline battery clips to the top of the box using Denecke's patented quick snap design. A fresh battery lasts up to 8 hours. The external AC power connector could alternatively be plugged into the top. The AD-20 samples at 44.1kHz and produces a SCMS=00 signal.

If you want to use the AD-20 to digitize a line level signal (like a CD or DAT output), rather than a microphone signal, we offer line level attenutor cables; for a stereo signal, you'll need two of them.

The AD-20 comes with a miniphone-plug-to-RCA S/PDIF cable.

The blue aluminum box measures about 3 x 5.75 x 1.25 inches and weighs about 1 pound. It has a belt clip on the back panel.

The optional 7-Pin cable is detachable from the AD-20. One end of the one-foot cable is a mini-XLR plug that plugs into a mating jack on the AD-20. The other end of the cable is a Core Sound right-angle 7-pin plug.

The AD-20 does NOT have any meters on it, the intent is to use the meters on your DAT deck or Digital Audio Workstation (when used with a ZA2 or other digital card).

The AD-20 does not provide phantom power (P48). If your microphones require phantom power, consider using a dual channel, battery-powered phantom power supply -- they're available from Rolls (the PB224) and Denecke (the PS-2).