GRAS 26AG 1/2'' Insert Voltage Preamplifier with Integrated Connector

Freq range: 2.5 Hz - 200 kHz
Noise: 1.8 µV
Gain: -0.25 dB
Special feature: Insert voltage for determining open-circuit sensitivity of a microphone

The GRAS 26AG is a small robust preamplifier with insert voltage calibration facility. It has a very low inherent noise level, a wide dynamic range and a frequency response from below 2 Hz to above 200 kHz.

Technology

Typical application & use

Precision measurements

Low-pressure measurements

General-purpose preamplifiers

Design

All GRAS microphone preamplifiers are based on a small ceramic thick film substrate with a very high input impedance. The ceramic substrate is shielded by a guard ring to minimise the influence of stray capacitance and microphonic interference. The casing is made of stainless steel for maximum strength and durability. The small dimensions of the 26AG preamplifier ensures reliable operation under humid conditions owing to the heat generated by internal power dissipation.

 

Compatibility

The 26AG preamplifier is compatible with ½-inch microphones as defined in international standard IEC1094 Measurement Microphones, Part 4: Specifications for working standard microphones. The mounting thread (11.7 mm - 60 UNS-2) is compatible with other available makes of similar microphone preamplifiers.

The 26AG is integrated with a 7-pin LEMO series 1B plug and comes with an insert-voltage calibration facility for determining the open-circuit sensitivity of condenser microphones.

Connector

7-pin LEMO 1B male (ext. view)

 

 

 

 

Specifications

Frequency range (±0.2 dB) with 18 pF microphone dummy
Hz
2.5 to 200 k
Slew rate
V/µs
20
Input impedance
GΩ // pF
20 // 0.4
Output impedance
Ω
75
Output Voltage Swing, max. @ ±14V/+28V power supply
Vp
12
Output Voltage Swing, max. @ ±60V/+120V power supply
Vp
50
Noise (A-Weighted) max.
µV
2.5
Noise (A-Weighted) typ.
µV
1.8
Noise (Linear 20 Hz – 20 kHz) max.
µV
6
Noise (Linear 20 Hz – 20 kHz) typ.
µV
3.5
Gain
dB
-0.25
Power supply, single
V
28 to 120
Power supply, balanced
V
±14 to ±60
DC-offset, min., single suppy
V
0.5 x Vs - 1
DC-offset, max., single suppy
V
0.5 x Vs + 4
DC-offset, balanced supply
V
-1 to 4
Temperature range, operation
°C / °F
-30 to 70 / -22 to 158
Temperature range, storage
°C / °F
-40 to 85 / -40 to 185
Humidity range non condensing
% RH
0 to 95
Connector type
7-pin LEMO (FGG.1B.307)
CE/RoHS compliant/WEEE registered
Yes / Yes, Yes
Weight
g / oz
34.0 / 1.24

Conditions: 23 °C Ambient temperature, ±60V/+120V power supply, 18 pF dummy microphone, 3 m output cable.

 

Low frequency response for various microphone capacities

 

Max. RMS output signal for various cable loads with 120 V supply


GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.

Dimensions

Ordering info

Optional items

GRAS AA0008

3 m LEMO 7-pin - LEMO 7-pin Cable

GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.