The G.R.A.S. ½-inch Preamplifier Type 26TK is a small robust unit optimised for acoustic measurements using condenser microphones. It has a very low inherent noise level, a wide dynamic range and a frequency response from below 2Hz to above 200kHz.
All G.R.A.S. 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 these preamplifiers ensure reliable operation under humid conditions owing to the heat generated by internal power dissipation.
This preamplifiers is compatible with ½-inch microphones as defined in international standard IEC 1094 Measurement Microphones, Part 4: Specifications for working standard microphones. The mounting thread (11.7mm – 60 UNS-2) is compatible with other available makes of similar microphone preamplifiers.