Introduction to Amplifier Reviews

Amplifiers can be considered in three subcategories: Preamplifiers, Integrated Amplifiers and Power Amplifiers.

Preamplifiers handle small signal switching and gain or attenuation (volume control). In many cases, these products have balance controls, equalization or even automated room correction. Preamplifiers may also contain phono preamps, DACs, video switching, headphone amps and streaming/playback of digital files to name just a few additional features you may encounter. There are several different circuit topologies on the market, some are quite simple and others very complex. Preamplifiers do not have amplification to drive speakers and for this purpose you will need to add a separate power amplifier.

Integrated Amplifiers : take a preamplifier, add a stereo amplifer in the same chassis and you have an integrated amplifier. Though more convenient, this is widely regarded as less desirable than having a separate preamplifier and power amplifier as this isolates the small and large signal sections far better than with integrated amplifiers. Integrated amplifiers can have all the features of preamplifiers. They are also available in solid state, vacuum tube or hybrid designs.

Power Amplifiers provide the power to drive your passive loudspeakers. Like all the other amplification components, they can come in a variety of styles. It is of the utmost importance to select an amplifier that is compatible with your speakers and with sufficient power to fill your room with music.

All our reviews feature breakdowns of the product design, product setup and notes on the performance with subjective listening impressions. Most of our reviews also include our own objective bench tests which tell you how much distortion an amp has, its frequency response and, in many cases, its maximum power output, irrespective of manufacturers' claims.

Review Categories

Preamplifiers

Wireless Amplifiers

Integrated Amplifiers

Power Amplifiers

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Amplifier Reviews

NAD M3 Integrated Stereo Amplifier

John E. Johnson, Jr.

If you look at the specs of most stereo integrated amplifiers, the rated RMS power output is between 60 watts and 120 watts per channel. This is lower than the power output of outboard power amplifiers, which typically are about 125 watts to 300 watts per channel. Monoblocks go all the way up to 2,000 watts output. One of the main reasons for this is that in an integrated power amplifier, the preamplifier circuit is situated very close to the power amplifier. Keeping the high voltage, high current power amplifier signal from inducting noise into the preamplifier circuit is difficult. NAD apparently has solved this problem with the introduction of their M3 Integrated Amplifier, which has a rated output of 180 watts per channel, at 0.004% THD+N, and clipping (1% THD+N) at 220 watts.

Integrated Amplifiers

Anthem P2 Two-Channel Power Amplifier

John E. Johnson, Jr.

Anthem's statement multi-channel power amplifiers are called the P series. They come in two versions, a five-channel (P5) and a two-channel (P2). My home theater test lab has a 200 watt x 5 amplifier which works great for the majority of applications, but it is driving electrostatic speakers (ESLs), and for a handful of Blu-ray movies, the amplifier will go into protect mode when at high volume, because ESLs typically have a very low impedance (1 ohm) in the high frequency range.

Power Amplifiers

Classe CP-800 Stereo Preamplifier

John E. Johnson, Jr.

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.

Preamplifiers

Pass Labs X1000.5 Monoblock Power Amplifier

John E. Johnson, Jr.

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.

Power Amplifiers

Ming Da MD-75 Integrated Stereo Tube Amplifier

John E. Johnson, Jr.

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.

Integrated Amplifiers

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

David A. Rich, Ph.D.

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.

Integrated Amplifiers

Earthquake Sound Cinenova 7 Multi-Channel Power Amplifier

John E. Johnson, Jr.

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.

Power Amplifiers

Parasound New Classic 5250v.2 Multi-Channel Power Amplifier

Jared Rachwalski

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.

Power Amplifiers

Pass Labs XP-20 Stereo Preamplifier

John E. Johnson, Jr.

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.

Preamplifiers

Paradigm Signature S2, Version 3 Bookshelf Speakers and Anthem Integrated 225 Amplifier

Chris Heinonen

The CEDIA Expo isn't really a show for audiophiles. Most of the setups are geared towards in-wall speakers, projectors, and other various forms of home automation, but there are always a few vendors there that have some nice demonstrations. This year, one of my favorite demonstrations came from Paradigm, who had a complete home theater built with their Signature S2, Version 3s as the front speakers.

Integrated Amplifiers

Mark Levinson Nº 531H Monoblock Power Amplifier

Jim Clements

Mark Levinson is one of the world's great high end audio manufacturers. They make a wide variety of electronic components, including pre amps, DACs, CD transports, SACD players as well as a surround sound processor they call a "Media Console". Levinson has also teamed with luxury auto manufacturer, Lexus so you can take their audio products on the road. Nonetheless, Mark Levinson is almost certainly best known for their very large, very powerful and very expensive power amplifiers. They enjoy a well deserved reputation for making some of the best - if not the best - solid state power amps around. The Nº 531H is the subject of the current review, and it delivers 300 watts RMS into 8 ohms.

Power Amplifiers