Amplifier Reviews
Classe CP-800 Stereo Preamplifier
- Written by John E. Johnson, Jr.
- Published on 25 April 2012
Classé's new CP-800 is a high performance ("High-End") stereo preamplifier, but it is not just yet another preamp with minor changes from previous models. This one has the option of switching in some DSP that adds several EQ bands and dedicated stereo subwoofer outputs. If you don't use the DSP, it's not in the signal path, and you can still call yourself a "purist" audiophile. Have no doubts; this is a very unique product, and the performance is stellar.
Pass Labs X1000.5 Monoblock Power Amplifier
- Written by John E. Johnson, Jr.
- Published on 13 February 2012

We have reviewed several Pass Labs products in the past, and I finally decided to get a pair of what they call "Room Heaters", i.e., the X1000.5. These monoblock power amplifiers are rated at 1,000 watts rms into 8 ohms. They are similar in physical design to the XA200.5, but the XA200.5's are biased into Pure Class A, while the X1000.5's are biased about 80 watts into Class A, with the rest as AB.
Harman Kardon HK 990 Stereo Integrated Amplifier with Digital Room Correction and Dual Subwoofer Bass Management – Part I
- Written by Dr. David A. Rich
- Published on 20 October 2011

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.
Pass Labs XP-30 Stereo Preamplifier
- Written by John E. Johnson, Jr.
- Published on 01 December 2011
Recently, we reviewed the Pass Labs XP-20 stereo preamplifier, and it was marvelous. Hot on its heels is the new XP-30...
Jones Audio PA-M300 Series 2 Monoblock Power Amplifier
- Written by Jason Victor Serinus
- Published on 19 September 2011

Imagine my surprise when Secrets' Editor-in-Chief, John Johnson, asked me if I would review a pair of Jones Audio's 300W solid-state monoblock power amplifiers. "Now that would be quite a switch," was the first thought that popped into my head.
Ming Da MD-75 Integrated Stereo Tube Amplifier
- Written by John E. Johnson, Jr.
- Published on 24 November 2011

Ming Da is company based in China that exports tube preamplifiers, power amplifiers, and integrated amplifiers in various price ranges, including some very high end models. They sell direct, through Pacific Valve, rather than through dealers, so you really get a good bang for the buck. In this review, my first of a Pacific Valve product, is on the MD-75, which is a stereo integrated amplifier. It has a detached power supply for low noise and interference, a remote for the motorized volume control, and you can switch between triode mode (40 watts/channel output) and ultra-linear mode (75 watts/channel output). You can "tube roll" if you wish, and the review unit came with optional Black Treasure CV-181 driver tubes and Black Treasure KT88 output tubes.
One very nice feature of this product is that, when you turn it on, the volume control rotates to the lowest volume setting, so you don't accidentally start playing music at a volume that might startle you.
Earthquake Sound Cinenova 7 Multi-Channel Power Amplifier
- Written by John E. Johnson, Jr.
- Published on 22 August 2011

Earthquake Sound, besides manufacturing very powerful subwoofers, also offers very powerful amplifiers for your home theater. The massive Cinénova Grande 7 is rated at 500 watts output per channel (seven channels) into 8 ohm loads. At $6,000, it is one of the most powerful multi-channel amplifiers in the world. But, many consumers don't need that much power, either because their home theater is small, or they just don't watch movies and listen to surround sound music very loud. So, Earthquake Sound has introduced the Cinénova 7, a seven-channel power amplifier, which is rated at 150 watts output per channel into 8 ohms.
Harman Kardon HK 990 Stereo Integrated Amplifier with Digital Room Correction and Dual Subwoofer Bass Management – Part III
- Written by Dr. David A. Rich
- Published on 03 November 2011

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.
Parasound New Classic 5250v.2 Multi-Channel Power Amplifier
- Written by Jared Rachwalski
- Published on 15 August 2011

Parasound builds many audio products such as amps, tuners, preamps, and products for custom installations. As well their products can be found in many movie studios, including Lucasfilm and Pixar, you can even see their name in the credits for Star Wars. As well they are known for their highly regarded stereo products designed by John Curl. Their New Classic line has been around for many years and Parasound has released an updated five channel amplifier from this line, named the 5250v.2 which is a powerful and rugged THX Ultra-2 Five channel amplifier.
Harman Kardon HK 990 Stereo Integrated Amplifier with Digital Room Correction and Dual Subwoofer Bass Management – Part II
- Written by Dr. David A. Rich
- Published on 27 October 2011

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.
Pass Labs XP-20 Stereo Preamplifier
- Written by John E. Johnson, Jr.
- Published on 01 August 2011
After having tested a Pass power amplifier and phono preamplifier, I could not wait to get my hands on a preamplifier, to complete the system analysis. The subject of this review is the venerable XP-20, which has been in the Pass inventory since 2009. It's a fully balanced design, with separate power supply chassis for low noise. The bench test results were quite surprising. Read on to see for yourselves.






Amplifier Reviews








