The Heritage Audio HA-609A is a modern take on the classic tracking/mixing diode bridge compressor with several improvements brought in to accommodate faster workflows. While some classic iterations of this design utilized some IC chips and a class A/B amplifier stage, the HA-609A features an entirely discrete, class A design and a total of three Carnhill/St Ives transformers per channel. The addition of a fast attack mode for both the compressor and limiter section allow the HA-609A the flexibility to handle individual tracks as well as groups and 2-bus program material. Thanks to a proprietary system of diode bridge gain reduction cells introduced with the highly regarded Successor, the HA-609A has better channel matching than any earlier incarnations, while the use of rotary switches and high quality, stepped pots allow for easy recall and maintain a perfect stereo image.