The front and back of the AT-101 has been re-engineered. The front panels have new hinges fitted so both panels open outwards providing easy and simple access. The back layout is basically the same with new transformers fitted there are labeled XLR connections on the left and a switched IEC mains power inlet socket to the right. All tube sockets are the same. The rigid chassis provides secure mounting for all the transformers and hardware providing a high degree of thermal stability.

Much of the AT-101 uses the original power supply this includes the HT circuit which provides power for all the tubes allowing a slow ramped start for the circuit. Typically tubes draw large amounts of current when switched on from cold potentially causing damage to the heater element and shortening the life of tubes, so a new low voltage supply replaces the old constant voltage transformer. It provides a soft-starting ramped linear DC heater voltage for the gain reduction stage that has been designed to switch on slowly after the unit is powered up. In addition to increasing the life of these heater elements it now has a lower noise floor. This supply has been overrated. Rise time 2 seconds