G.R.A.S. 26CI 1/2'' CCP Preamplifier with BNC Connector, Low Frequency

Freq range: 1 Hz - 200 kHz
Noise: 1.8 µV
Gain: -0.35 dB
Special feature: Low frequency

Typical applications and use

CCP inputs

Prepolarized microphones 

1/2" precision microphones

High levels and high frequencies


The G.R.A.S. 1/2" Preamplifier G.R.A.S. 26CI is a small, robust unit and uses a G.R.A.S. CCP power supply, e.g. G.R.A.S. 12AL. It has a very low inherent noise level, a large dynamic range and a frequency response from 1 Hz to above 200 kHz.

Its small ceramic thick-film substrate has a very high input impedance, and is shielded by a guard ring to minimise the influence of stray capacitance and microphonic interference.

The G.R.A.S. 26CI is provided with a built-in TEDS* chip, and can be programmed as a single unit with a microphone fitted. It is primarily intended for the low frequency microphone 46AZ but can be used with all G.R.A.S. 1/2" prepolarized microphones and with adapters with other microphone sizes.

It has an integrated BNC output connector. The casing is made of stainless steel for maximum strength and durability.

* Transducer Electronic Data Sheet - as proposed by IEEE-P1451.4

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 < 50
Output Voltage Swing, min. @ 24-28 V CCP voltage supply Vp 8
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 -0.35
Power supply (Constant Current Power) mA 2 to 20 (typical 4)
DC bias voltage, typ. V 12
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 - 95
TEDS UTID (IEEE 1451.4) 769 v. 0.9
Connector type BNC
CE/RoHS compliant/WEEE registered Yes / Yes, Yes
Weight g / oz 26.0 / 0.92
Conditions: 23 °C Ambient temperature, 4 mA / 24 V open loop CCP voltage, 18 pF dummy microphone, 3 m output coax-cable. G.R.A.S. Sound & Vibration reserves the right to change specifications and accessories without notice.

Optional items

G.R.A.S. AA0035

3 m BNC - BNC Cable

G.R.A.S. AA0039-CL

Customized Length BNC - BNC Cable

G.R.A.S. AL0008

1/2" Microphone Holder, POM

G.R.A.S. AL0012

1/2" Microphone Holder, Stainless Steel

G.R.A.S. AL0005

Swivel head

G.R.A.S. AL0006


G.R.A.S. RA0019

Adapter for 1/4" microphone and 1/2" preamplifier

G.R.A.S. RA0073

Adapter for 1" microphone and 1/2" preamplifier

G.R.A.S. RA0190

Right-angled (90º) Adapter for 1/2" Microphone and 1/2" Preamplifier

G.R.A.S. RA0018

20 dB Attenuator for prepolarized 1/2" microphones

G.R.A.S. RA0062

20 pF Preamplifier-input Adapter for 1/2" preamplifiers

G.R.A.S. 12AL

1-Channel CCP Power Module with A-weighting filter

G.R.A.S. 12AQ

2-Channel Universal Power Module with signal conditioning and PC interface

G.R.A.S. Sound & Vibration reserves the right to change specifications and accessories without notice.