Schoeps CMBI Battery-Powered Microphone Amplifier, incl. K5ISK, Battery, SG 20
If a recorder has no phantom powering or a microphone input is unbalanced as in many portable recorders and wireless microphone transmitters, a phantompowered microphone can be awkward to use. For these and other situations SCHOEPS offers the CMBI, a battery-powered microphone amplifier with unbalanced output.
Combine this with one of 19 microphone capsules of the Colette series and you obtain a microphone which is acoustically equivalent to the balanced version using a CMC microphone amplifier.
- unbalanced, medium-impedance output
- for use with short cables (a few metres)
- for connection to any desired microphone input without phantom power
Application
The CMBI features a readily available internal 6 V silver oxide battery, which, combined with power saving circuitry, gives up to 80 hours of operation. About 6 hours before the end of battery life a built-in LED begins to light up as a warning.
In addition to battery operation, the CMBI allows for external powering as well (The included K 5 ISK cable is not suitable for this mode of operation.)
Because of this model's unbalanced, low-level output and its medium output impedance, the total cable length should be kept to less than about 15 m to avoid possible RF interference and impaired performance.
Possible arrangements for connecting the CMBI are shown on the following page.
Instead of a large XLR connector, the CMBI has a flush-mounted 5-pin miniature connector at the output which also allows for external powering. For normal connection of the CMBI to a DAT recorder, etc., a 5 m cable with a 3.5 mm mini stereo plug is included. This cable can be extended with a stan dard 3.5 mm stereo jack to stereo plug cable, or with a miniature connector extension cable such as SCHOEPS KS 5 I.
For operation with pocket transmitters, we have readymade cables with special connectors on request.
For stereo recordings, there is a Y-shaped cable (KIY 250/0 I) which connects two CMBI to a compact junction box by means of two pieces of cable, each 250mm in length. The short cable leading out of this box has a miniature connector and can be extended either with the K 5 ISK cable or with the extension cable KS 5 I.
Possibilities for connecting the CMBI
CMBI with capsule, battery and windscreen
Specifications
| Specifications |
| Sensitivity |
see corresponding capsule |
| Equivalent noise level |
see corresponding capsule |
| Switch setting “0 dB“: |
|
| Maximum output voltage |
0.7 V |
| Maximum sound pressure level at 0.5% THD |
RL > 10 kΩ: > 130 dB-SPL |
| Maximum sound pressure level at 0.5% THD |
RL= 1 kΩ: ca. 120 dB-SPL |
| Output impedance |
unbalanced, 500 Ω |
| Switch setting “-15 dB“: |
|
| Maximum output voltage |
ca. 0.14 V |
| Maximum sound pressure level at 0.5% THD |
at least 130 dB-SPL |
| Output impedance |
unbalanced, 300 Ω |
| Switch |
on (0 dB) / off / on (-15 dB) |
| Battery powering |
6 V silver oxide battery |
| Battery powering |
e.g. IEC 4 SR 44, maximum battery life: 80 h |
| External powering |
7 – 13 VDC, 1.7 mA |
| Output socket |
5-pin miniature |
| Diameter |
20 mm |
| Length |
without capsule: 92 mm |
| Weight |
72 g |
| Surface finish |
matte gray (g) or nickel (ni) |