Integrated Amplifiers

Harman Kardon HK 990 Stereo Integrated Amplifier with Digital Room Correction and Dual Subwoofer Bass Management – Part III


Conclusions About the HK 990 Circuit Design

I wrote much of this material in October 2010. At the time, my sole reference was the service manual (the actual unit arrived several months later). I intended the piece to be a preview of the HK 990, which had just been shown at CEDIA. Since then, the HK 990 received a positive review from Tyler Stripko and at least one other professional reviewer. It is rare for a relatively low-priced unit to achieve such consistently positive reviews. I will not comment about my impressions of the sound of this amplifier, other than to note that Tyler's positive sentiment may be justified by the work of Otala. Every design decision is backed up with some quantitative analysis. The HK990 is a polar opposite of designs offered by others where the design techniques are more closely allied to black magic than solid engineering and expensive metalwork wraps the questionable design to give the look of ultra high tech. A five-figure price is tacked on to enhance the aura of ultimate performance. Poor measured results are often a consequence when black magic replaces science. The component may sound different, but different is not necessarily better.