Not all amplifiers are created equal and among the best are those from Chord Electronics. Unlike other amplifiers that use bipolar transistors in their output stages, Chord Electronics amplifiers use custom-designed MOSFET devices developed exclusively for Chord Electronics. This brings perfect thermal matching to the amplifier's components, reducing the need for temperature balancing resistors. The result is a more efficient and higher-performing amplifier. Among these is the 180W Ultima 6 stereo amplifier.
Noel Keywood investigated the Chord Electronics Ultima 6 amplifier for the October 2020 issue of Hi-Fi World. After a brief review of the design and look of the amplifier, Keywood began to dive into the technical aspects of the amplifier and what sets the Ultima 6 apart from other amplifiers. Most important among these are Chord Electronic's unique power handling technology. The MOSFET transistors in the switch mode power supply are the key to Chord Electronic's highly efficient amplifiers, and Keywood does a great job giving an overview of the technology. (For a detailed explanation of Chord Electronics' amplification technology, please see the Chord Electronics website.)
Moving on the from the technical aspects, Noel begins to test the Ultima 6 using a pair of Martin Logan electrostatic speakers, Chord Company Signature Reference speaker cables, a Chord Electronics Dave DAC, Chord Epic XLR cables, and an Oppo digital player. Upon starting up the system, Keywood noticed the Ultima 6 was not your ordinary amplifier:
The qualities of Ultima 6 soon became apparent. It conveys a sense of rigidly imposed structure on music, holding instruments into tight lock on the sound stage, giving plenty of dynamic headroom to allow crescendos to rise unhindered.
Luckily, he doesn't stop there. After a few more test tracks and system changes, Noel took the Ultima 6 to the lab to get some technical readings on the Frequency Response, Power, Distortion, Noise, and Sensitivity. In doing these tests, they found that the Ultima 6 was actually pushing 312 Watts in an 8 ohm load, rather than the rated 180 Watts. This means you're getting more power than you're paying for, allowing to drive even bigger speakers with less distortion. You can see the effect this has on the level of distortion with just .0005% distortion in the midband and .03% in the high end. For the full test results, be sure to check out the article.
In the end, Hi-Fi World scores the Ultima 6 as a 5/5, noting that it is "Outstanding - among the best" for its high-tech sound, ease of use, and huge power. To read the whole article, including lab measurements, click the link below.