Circuit design and the tape recorder section are the focus of the final section of my HK 990 review. The topics are addressed to different groups. Those interested in the tape recorder section will find information on Page 9. The tape recorder interface section outlines matters of connectivity and usage. Usability issues are discussed. The tape recorder interface section is at the level of the prior two parts and assumes no knowledge of circuit-level electronics.

The circuit-design section enters the land of high-end design, mostly guided by the design principles of Matti Otala. My intent is two-fold: to identify anything that might make the unit sound better subjectively; and to objectively quantify whether any aspects of the design have inadvertently degraded performance.  Here are links to Part I and Part II of this series.

Tags: Amplifiers | Integrated Amplifiers | Stereo

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 II.

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....

Tags: Amplifiers | Integrated Amplifiers | Stereo

The HK 990 is a truly unique stereo component. It is a dual domain device capable of accepting analog or digital inputs, converting domains as required, and sending the results to the speaker. A complex room-correction system in a stereo integrated amplifier separates the HK 990 even further from comparables. For those who archive vinyl or magnetic tape to CD-R, the dual domain nature of the HK 990 tape record function provides unique functionality.

This review is independent of Tyler Stripko’s review published in June, 2011, where Tyler comments on a different sample. This review concentrates on measurements and internal design of the HK 990 and fits nicely together: Tyler covers the listening impressions.

Tags: Amplifiers | Integrated Amplifiers | Stereo

Most likely recognized in today’s market as a purveyor of home theater receivers, desktop/PC speakers, iPod docks, and factory-installed automotive sound systems, Harman Kardon is a name that is also well-recognized in traditional 2-channel audio. While the history of the company is quite interesting (see the “about us” link on the company’s webpage), one thing has remained constant at Harman Kardon over the years: they produce an aesthetically pleasing product that delivers the high-sound quality sought after by the brand’s customers. Here, we review their 990 Integrated Amplifier and HD 990 CD Player.

Tags: CD Players | Integrated Amplifiers

The D6 SACD player and A9 integrated stereo amplifier are two of four possible combinations in the Pioneer G-Clef series of SACD players and integrated two channel amplifiers that are sold as a pair. The G-Clef series is tested and approved by AIR Studios in London and are designed for the discriminating stereo lover in mind. As quoted from Pioneer’s website, “The AIR Studios quality seal is proof not only of the extraordinary engineering that has gone into these audio units, but also of the exceptionally high quality of their craftsmanship and carefully selected electronic components”.

Tags: Integrated Amplifiers | SACD Players

As a Quebec, Canada based company that has spent the last 30 years manufacturing some pretty outstanding gear, Simaudio has (like some other Canadian companies) made its name via its products' performance levels rather than hype and huge marketing spending. The unit reviewed here, the Simaudio Moon 700i Integrated Amplifier maintains that standing.

Tags: Amplifiers | Integrated Amplifiers

What’s in a Naim? For those not overly familiar with the brand (myself included), that has usually meant DIN connectors, the ubiquitous black casework, green lit circlet buttons and a reputation for an emphasis to PRat. This reputation for Pace Rhythm and Timing and a focus on hand built craftsmanship put Naim in a unique place amongst audio components.

Tags: Analog | Integrated Amplifiers | Stereo

Manley Labs designs and manufactures tube components. With the Stingray iTube, you can now plug your iPod directly into a dock on an integrated tube amplifier.The iTube can be switched between triode mode and ultralinear mode, giving you a choice in how much output the amplifier will deliver. It comes with a very unique remote control that you would only expect from Manley.

Tags: Integrated Amplifiers | iPod | Tubes

For nearly forty years, Nelson Pass has been designing simple, high-performance electronics. In 1991, with twenty years experience under his belt, he founded Pass Laboratories which has since become among the most highly regarded companies for high-end power and integrated amplifiers. His design goals couldn’t be more clear: power, simplicity and performance.

Tags: Amplifiers | Class A | Integrated Amplifiers

I have always been a fan of integrated amplifiers, and they were the heart of all my audio systems up until recently. They offer the best value in terms of getting the most performance per dollar, but they take away one thing many audiophiles love: fooling around with their system. Several ultra-high end companies have recently introduced very serious integrated amps, for the audiophile who is done with fooling around.

Tags: Amplifiers | Integrated Amplifiers