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

Amplifier Reviews

Pass Labs X600.8 600 Watt Monoblock Power Amplifier Review

With the success of the Pass Labs Xs series, Nelson Pass set out to create a line of additional power amplifiers that have most of what the Xs series has, but at much more affordable prices. The model under current review is the X600.8, which is a monoblock specified at 600 watts RMS output, with the first 50 watts in Pure Class A, and the rest in AB. Do they sound close to the Xs amplifiers? Read on.

NewClear Audio NC1000L Class D Stereo Power Amplifier

Class D (i.e., "Switching") amplifiers have been around for quite a while now. What's clear from models produced so far is they all sound different, even when using the same core technology. Like many amplifiers of the type, the NewClear NC1000L uses the Bang and Olufsen ICEPower module. What makes the NC1000L different isn't this module; it's how that module is implemented. NewClear Audio was started by Sean Brady to improve upon the sound of existing switching amplifiers. Sean had heard some very good amps based on ICEPower technology, but thought he could do even better. The question is, does the NC1000L deliver the goods compared to similarly priced, traditional Class A/B amplifiers?

Krell S-550i Integrated Amplifier

The S-550i is the larger of two new integrated amps from Krell. Both of these amps feature circuit boards that utilize surface mount components. This means they can pack more power into smaller chassis than ever before. The S-550i is rated at 275 watts per channel into 8 ohms, and that doubles to 550 wpc into a 4 ohm load. This being from a box that is less than 6 inches tall. So now you can get tons of Krell goodness in a small package and at a very affordable price.