The A21SE Integrated Amplifier is a single ended solid state pure class A design. The pre-amplifier has a cascode input stage, current feedback with the input and output being in phase. Other design points include high input impedence, high voltage gain in the first stage with low distortion, wide bandwidth, low noise and very low output impedence. Left and right line stages have current shunt power supplies from a dedicated transformer winding. The input signals are relay switched reducing signal paths to a minimum. The line stages (left and right) are supplied by their own current shunt power supplies driven by a separate transformer winding. This new power supply combined with minimal input signal path, relay switched input facilities and the new line stages give Sugden the opportunity to fully exploit the benefits of the Pure Class A power output stages.