In depth analysis and discussion of the design and circuitry of a stereo integrated amplifier, including digital room correction and dual subwoofer bass management:  evaluating the HK 990 Stereo Integrated Amplifier.

This 3-part series provides a detailed discussion of the electronics and design of the stereo integrated amplifier.

Part 1 provides an overview and covers room correction systems.

Part 2  considers the challenges of adding digital inputs and digital signal processing to a stereo integrated amplifier, using block diagrams as illustrations. This segment is a good read for those interested in the internal operation of an AVR at the block level. Since the HK is a stereo unit, the blocks are less complex. Once you have a handle of the operations at a block level, then the transition from two to seven, or even eleven, channels becomes more straightforward. The second segment also comments on the quality of the data converters in the HK 990 and additional performance data when the unit processes a high resolution file.

Part 3 turns to the design and construction of the HK 990 at the circuit level. The analysis starts with the analog circuits in the direct mode, which is equivalent to an analog integrated amplifier. The designs of the power amp and phono stage are in the spotlight, and we also look at the tape recorder output and monitor function in more detail.


Tags: Circuit Design, Room EQ, Bass Management, Stereo Integrated Amplifier, Digital Room Correction