MC741A/B Signal Conditioner_BSWA Technology Co., Ltd.

MC741A/B Signal Conditioner

MC741A/B signal conditioner can provide 200 V polarization voltage for external polarized microphones and also provides ±15 V or ±60 V power supply to preamplifiers. The device has single channel LEMO input and BNC output and supports both battery and external power supply options. Specifically, the MC741A supports a wide DC voltage range of 7 V~30 V, while the MC741B is powered by three LR6/AA batteries.

MC741A/B also offers signal conditioning with gain of x0.1, x1, x10, x100, as well as linear, band-pass (20 Hz~20 kHz), A-weighting, and C-weighting filters. The polarization voltage can be set to 0 V or 200 V, with the ±60 V supply only available for x0.1 gain.

MC741A/B has an all-aluminum housing, which can effectively shield the internal signal. The LED indicator displays the power supply status and input overload conditions. The device has a 60 Vp input and output protection circuit, which can protect sensors and data acquisition equipment.

MC741A/B supports TEDS, DIR OUT and Self-Check functions. If not in use, TEDS and Self Check should be turned off to avoid affecting signal quality.

The TEDS function only line out the TEDS signal. It’s also need a dedicated TEDS reader/writer to access TEDS information.

DIR OUT function can directly output the preamplifier signal, in which case the output noise and frequency response are completely determined by the preamplifier, and the output bias voltage may increase slightly. ★Note that this function should only be used by experienced operators, improper use may damage the preamplifier or data acquisition equipment.

Features:

● Provides 200 V polarization voltage for externally polarized microphones

● Provides ±15 V or ±60 V power supply for preamplifier

● Single-channel LEMO input and BNC output connector

● 4-stage gain (x0.1, x1, x10, x100)

● Linear, Band-pass (20 Hz~20 kHz), A-weighting and C-weighting filters

● TEDS, DIR OUT, and Self-Check functions

● MC741A is powered by power adapter, while MC741B is powered by battery

Applications:

● Power supply for the external polarized microphone and attached preamplifier

● Common signal conditioner (amplifier and filter)

MC系列技术参数

Specifications：

Input Channel 1 x LEMO (EGG.1B.307)

Output Channel 1 x BNC

Amplifier Gain x0.1 (-20 dB) x1 (0 dB) x10 (+20 dB) x100 (+40 dB)

Gain Tolerance (1 kHz) ±0.05 dB ±0.05 dB ±0.05 dB ±0.05 dB

Linearity <0.1 dB

Preamplifier power supply voltage ±60 VDC ±15 VDC ±15 VDC ±15 VDC

Maximum Input Volt.
(OVLD Indication) ±60 Vp ±10 Vp ±1 Vp ±0.1 Vp

Maximum Output Volt. ±6 Vp ±10 Vp ±10 Vp ±10 Vp

Input Protection Volt. ±60 Vp ±15 Vp ±15 Vp ±15 Vp

Maximum Non‐destructive Input Volt. ±70 Vp ±70 Vp ±70 Vp ±70 Vp

Output Impedance 110 Ω (101.5 Ω typ.)

Total Harmonic (THD+N)
≤-80 dB
(-84 dB typ.)
≤-95 dB
(-97 dB typ.)
≤-75 dB
(-77 dB typ.)
≤-75 dB
(-76 dB typ.)

Output Bias Voltage ≤5 mV

Filter Linear, Band-pass (20 Hz~20 kHz), A-weighting, C-weighting

Frequency weighting at1 kHz ¹ LZ – LA ≤ ±0.1 dB, LC - LA ≤ ±0.3 dB

Lin.

Freq.
Resp. (±0.3 dB) 3.15 Hz~315 kHz 3.15 Hz~315 kHz 3.15 Hz~125 kHz 3.15 Hz~25 kHz

(+0.3 dB/-3 dB) 3.15 Hz~500 kHz 3.15 Hz~315 kHz 3.15 Hz~315 kHz 3.15 Hz~100 kHz

BP Freq. Response
(+0.3 dB/-2 dB) 0 Hz ~ 20 kHz (-3 dB Typ. Cut-off Freq.: 17.5 Hz、24.3 kHz)

A/C-W Freq. Response Complies with IEC 61672 Class 1

Output

Noise
(uVrms) Lin (AW)² <3 (2.1 typ.) <3 (1.6 typ.) <14 (12.0) <82 (75.7 typ.)

Lin <4 (3.0 typ.) <4 (2.4 typ.) <19 (16.2) <110 (100.9 typ.)

BP <8 (4.7 typ.) <8 (4.2 typ.) <20 (17.5) <118 (108.1 typ.)

AW <8 (4.7 typ.) <8 (4.5 typ.) <17 (14.3) <95 (85.9 typ.)

CW <8(3.8 typ.) <7 (3.3 typ.) <15 (11.6) <78 (70.6 typ.)

LED Indicator
PWR LED: Power indicator
OVLD LED: Green=Normal, Red=Input Overload

TEDS
SMB connector, line out the preamplifier TEDS pin (if available), switch to OFF when not in use

DIR OUT
SMB connector, direct output of preamplifier

Self-Check
SMB connector, line out the preamplifier self-check pin (if available), switch to OFF when not in use

Power Supply
MC741A: 7 V~30 V DC power supply, ≥300 mA
MC741B: LR6/AA batteries x 3

Operating Temperature Range
-10 °C ~ 50 °C

Operating Humidity Range
0 %RH ~ 95 %RH (no condensation)

Dimensions (mm)
W82 x H44 x D133

Weight
289 g

Note 1: For a steady sinusoidal electrical input signal at 1 kHz, the measured difference between the indicated level of C-weighted measurement quantity and the indicated level of the corresponding A-weighted measurement quantity (LC-LA) does not meet the requirements of IEC 61672 (≤± 0.2 dB). Users can adjust the C-weighting by adding 0.25 dB gain to meet the standard.
Note 2: Lin (AW) measures the A-weighted output noise of Lin. output, where the A-weighted filtering is implemented by an external measurement device (post-processing).

Input Channel	1 x LEMO (EGG.1B.307)
Output Channel	1 x BNC
Amplifier Gain	x0.1 (-20 dB)	x1 (0 dB)	x10 (+20 dB)	x100 (+40 dB)
Gain Tolerance (1 kHz)	±0.05 dB	±0.05 dB	±0.05 dB	±0.05 dB
Linearity	<0.1 dB
Preamplifier power supply voltage	±60 VDC	±15 VDC	±15 VDC	±15 VDC
Maximum Input Volt. (OVLD Indication)	±60 Vp	±10 Vp	±1 Vp	±0.1 Vp
Maximum Output Volt.	±6 Vp	±10 Vp	±10 Vp	±10 Vp
Input Protection Volt.	±60 Vp	±15 Vp	±15 Vp	±15 Vp
Maximum Non‐destructive Input Volt.	±70 Vp	±70 Vp	±70 Vp	±70 Vp
Output Impedance	110 Ω (101.5 Ω typ.)
Total Harmonic (THD+N)	≤-80 dB (-84 dB typ.)	≤-95 dB (-97 dB typ.)	≤-75 dB (-77 dB typ.)	≤-75 dB (-76 dB typ.)
Output Bias Voltage	≤5 mV
Filter	Linear, Band-pass (20 Hz~20 kHz), A-weighting, C-weighting
Frequency weighting at1 kHz ¹	LZ – LA ≤ ±0.1 dB, LC - LA ≤ ±0.3 dB
Lin. Freq. Resp.	(±0.3 dB)	3.15 Hz~315 kHz	3.15 Hz~315 kHz	3.15 Hz~125 kHz	3.15 Hz~25 kHz
(+0.3 dB/-3 dB)	3.15 Hz~500 kHz	3.15 Hz~315 kHz	3.15 Hz~315 kHz	3.15 Hz~100 kHz
BP Freq. Response (+0.3 dB/-2 dB)	0 Hz ~ 20 kHz (-3 dB Typ. Cut-off Freq.: 17.5 Hz、24.3 kHz)
A/C-W Freq. Response	Complies with IEC 61672 Class 1
Output Noise (uVrms)	Lin (AW)²	<3 (2.1 typ.)	<3 (1.6 typ.)	<14 (12.0)	<82 (75.7 typ.)
Lin	<4 (3.0 typ.)	<4 (2.4 typ.)	<19 (16.2)	<110 (100.9 typ.)
BP	<8 (4.7 typ.)	<8 (4.2 typ.)	<20 (17.5)	<118 (108.1 typ.)
AW	<8 (4.7 typ.)	<8 (4.5 typ.)	<17 (14.3)	<95 (85.9 typ.)
CW	<8(3.8 typ.)	<7 (3.3 typ.)	<15 (11.6)	<78 (70.6 typ.)
LED Indicator	PWR LED: Power indicator OVLD LED: Green=Normal, Red=Input Overload
TEDS	SMB connector, line out the preamplifier TEDS pin (if available), switch to OFF when not in use
DIR OUT	SMB connector, direct output of preamplifier
Self-Check	SMB connector, line out the preamplifier self-check pin (if available), switch to OFF when not in use
Power Supply	MC741A: 7 V~30 V DC power supply, ≥300 mA MC741B: LR6/AA batteries x 3
Operating Temperature Range	-10 °C ~ 50 °C
Operating Humidity Range	0 %RH ~ 95 %RH (no condensation)
Dimensions (mm)	W82 x H44 x D133
Weight	289 g
Note 1: For a steady sinusoidal electrical input signal at 1 kHz, the measured difference between the indicated level of C-weighted measurement quantity and the indicated level of the corresponding A-weighted measurement quantity (LC-LA) does not meet the requirements of IEC 61672 (≤± 0.2 dB). Users can adjust the C-weighting by adding 0.25 dB gain to meet the standard. Note 2: Lin (AW) measures the A-weighted output noise of Lin. output, where the A-weighted filtering is implemented by an external measurement device (post-processing).

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MC741A/B Signal Conditioner