The GS551 consists of three gain blocks. The first block is an inverting amplifier with the gain set by two external resistors. The gain trim feature can be used as a volume control in hearing aid applications. The second block is an inverting unity gain amplifier which serves as a phase splitter. The outputs from the first and second blocks drive the differential input of the third block. The third block has a fixed AC gain of 28 dB when driving a receiver. The amplifier has internal compensation eliminating the need for a capacitor across the receiver. Two ground pins are available for "Star" grounding to reduce any second order harmonic distortion introduced by ground line resistance.