Measurement Microphone Preamplifier MV 240
The MV 240 digital is a 1/2 “measurement microphone preamplifier with an integrated analogue-digital converter.
The signal from the measuring microphone capsule is optimally adapted to the dynamic range of the analogue-digital converter with a low-noise and highly controllable impedance converter and a very low-noise and low-distortion preamplifier. The analogue-digital conversion itself takes place in two-level ranges with a word length of 24 bits each. An integrated processor combines the two-level ranges into a single-channel digital USB output signal with a word length of 32 bits, which corresponds to already calibrated sound pressure values. This means that a very large acoustic dynamic range of 7 dB to 160 dB is transmitted, which covers the entire dynamic range of a 1/2 “measuring microphone capsule.
No special driver is required to operate the MV 240 digital; it is automatically recognized by the operating system and can be used under Windows, macOS and Linux. The MV 240 digital is supplied with power directly from the USB interface. The polarization voltage of 200 V required for the operation of measuring microphone capsules is generated internally and can be switched off when using electret measuring microphone capsules. The connection to the USB interface is made via a lockable LEMO® connector with a corresponding LEMO® – USB adapter cable. With two integrated generators, the signal processing of the subsequent measuring chain can be checked in 32-bit number format and the reference point for a sound pressure of 1 Pascal can be determined.
|ADC||Sigma-Delta converter, 24 bit, 192 kHz
2 level ranges
|Output signal||USB, 1 channel, 32 bit
permanently calibrated sound pressure values
|Operating voltage||5 V (± 5%)|
|Power consumption||500 mA (at Ui = 10 Veff)|
|Frequency range||1 Hz to 80 kHz|
|Limit sound pressure level||160 dB|
|Max. Input voltage||10 Veff|
|Input impedance||20 GOhm; 0.2 pF|
|Sampling frequency||192 kHz|
|Polarization voltage||200 V|
|Remote control||Polarization voltage
on / off
|Connection standards||USB 2.0 / USB 3.0|
|Connectors||4-pin LEMO® EGG.9B.304.CLL|
|Capsule connection thread||11.7mm 60 US|
|diameter||12.7 mm / 21 mm|