The 26AI is a 1/2" microphone preamplifier with integrated 7-pin LEMO male connector and 40 GΩ input impedance.
Technology
Introduction
GRAS26AI is a preamplifier designed for low-frequency applications in the laboratory and field and accommodates directly for all IEC 61094 standardized 1/2" externally polarized measurement microphones.
It is rugged and reliable and can handle microphone signals up to 50 Vpeak within 1 Hz to 200 kHz. The printed circuit board is made by use of thick-film substrate technology and optimized with respect to maximum suppression of microphonics and moisture rejection.
The high-quality, standard 7-pin LEMO male connector is integrated into the preamplifier and ensures that only one type of connector and cable is required for both connection and extension.
26AI is factory calibrated individually and delivered with a calibration chart stating its A-weighted and linear self-noise.
Compatibility
These preamplifiers are compatible with 1/2-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.
GRAS 26AI is provided with an integrated 7-pin LEMO series 1B plug.
Specifications
| Parameter |
Unit |
Value |
| Frequency range (±0.2 dB) with 18 pF microphone dummy |
Hz |
1 to 200 k |
| Slew rate |
V/µs |
20 |
| Input impedance |
GΩ // pF |
40 // 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 |
-0.29 |
| 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 |
| TEDS (IEEE 1451.4) |
– |
769 v. 0.9 |
| Connector type |
– |
7-pin LEMO (FGG.1B.307) |
| CE/RoHS compliant/WEEE registered |
– |
Yes / Yes, Yes |
| Weight |
g / oz |
22 / 0.78 |
Conditions: 23 °C Ambient temperature, ±60V/+120V power supply, 18 pF dummy microphone, 3 m output cable.
GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.
Dimensions
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