Introduction to the Harman Kardon HK 990 Stereo Integrated Amplifier with Digital Room Correction and Dual Subwoofer Bass Management – Part II

This second part of the HK 990 review examines the signal flows in the HK 990 dual-domain integrated amplifier. This analysis is relevant to all units, including modem AVRs, with a DSP signal processing unit in the main signal path. The signal flow is more transparent in this stereo unit than a 7.1 multichannel unit; so, if you are interested in AVR, please stay tuned in to Part 2.

Analog circuit design methods for consumer high-fidelity products date to 1950 with the emergence of reel tape, LPs, and FM. Consumer-friendly discussions of analog component design are found in early (circa 1947) issues of Audio Magazine and early (circa 1951) issues of High Fidelity. Digital recording and CD players arrived at a time that magazines were still somewhat technical. It was not until Dolby Digital (originally called AC-3) started coming off Laser Discs in the mid-1990’s that units with core DSP processors appeared. By that time, the print magazines had de-emphasized technical aspects of design, preferring to focus on measurements results at the terminals of the DUT.

Part II of this series examines the dual-domain DSP based system at a deeper level than the treatment found in most reviews, but it is not so technical as to leave an interested audiophile puzzled.

If you missed Part I......