A transistor array used in exponential converter circuits in a number of analog synths, including the most common version of the Minimoog. It was also used in, among other things, early Buchla VCOs, early Roland synth models including the Jupiter 4, and most EML synths. What made the uA726 valuable for expo converter circuits was that it contained an onboard heater and thermostat mechanism to keep the chip temperature stable, eliminating the inherent temperature variability that is present in all analog expo converter circuits. By doing so, it also eliminated the need for a tempco in the circuit, and produced a more stable circuit.