The Arcam SA20 is an integrated amplifier, the more expensive of the two in the new HDA series. The device does not operate in class D, which has become very popular, but also not in A/B. Instead, the Arcam SA20 uses proprietary Class G technology, and today it is the most affordable device from this company with such amplification. The Arcam SA20 amplifier has a trendy industrial design that I like, and its front panel is intelligently organized. There is a display that shows the amplifier’s operating modes as well as all the controls so you don’t need a remote control. The finish of the device is not silver, not black or even grey, but it looks very attractive and allows the Arcam SA20 to look good alongside other hi-fi components.
Class G circuitry is an interesting attempt to overcome the disadvantages inherent in Class A/B. The most obvious of these is considered to be transient distortion (“step”), which occurs when the signal crosses the zero value, moving from the positive to the negative region. Over the past 30 years, many attempts have been made to solve this problem and the most interesting of them are to convert both output stages to pure class A or use pulse width modulation.
Arcam duplicated much of the SA20’s internal design. It has two power supplies, and the main components of the output stages are also connected in parallel. At low output power, the Arcam SA20 operates in class A, like amplifiers with A/B circuit design, but when you need to turn up the heat, an additional power supply comes into play. Arcam says the technology works effectively, although it is expensive and difficult to implement. However, if you use Arcam SA20 with very sensitive acoustics or at low volume levels, this additional output power may not be required. But having such a “reserve” will never be superfluous.
The Arcam SA20 amplifier has four RCA inputs, which is sufficient for most systems. Arcam SA20 also has a built-in phono stage for the MM pickup of a turntable. Arcam has always equipped its amplifiers with a phono input, and now this has become very popular. Unusual for Arcam models of this class is that the SA20 is also equipped with three digital inputs – two coaxial and one optical. The built-in DAC in the amplifier is based on the ESS Saber 9038K2M chip. The user has the opportunity to choose from seven digital filter operating modes to fine-tune the individual sound character of the amplifier.
Arcam SA20 has a headphone output on a 3.5 mini-jack connector, as well as an input on the same connector for quickly connecting signal sources. Screw terminals for connecting speaker systems are among the most reliable for equipment in this class. The amplifier is equipped with a convenient remote control, from which you can also control the CDS50 CD player and audio streamer. The amplifier is equipped with an Ethernet interface, which is used for network control in multiroom systems and will allow you to configure the operation of Arcam SA20.
Characteristics of Arcam SA20
Output power 2 x 90 W (8 Ohms)
Harmonic distortion 0.003%
DAC ESS9038K2M
Linear Aux inputs (3.5 mm, front panel), 3 linear RCA, MM phono preamp connectors (can be switched to line input mode), optical, 2 coaxial, LAN port
Pre Out outputs (RCA), headphone jack (3.5 mm)
Other switching RS-232, USB port for software update and power supply for additional equipment (5 V/100 mA), ground terminal
Speaker outputs 4 high quality screw terminals
Power consumption 500 W
Remote control universal, teachable, with backlit buttons
Weight 10.6 kg
