boXem | audio - Arthur 4222/E1
  • boXem | audio - Arthur 4222/E1
  • boXem | audio - Arthur 4222/E1
  • boXem | audio - Arthur 4222/E1
  • boXem | audio - Arthur 4222/E1
  • boXem | audio - Arthur 4222/E1
  • boXem | audio - Arthur 4222/E1
  • boXem | audio - Arthur 4222/E1

Arthur 4222/E1

1 channel power amplifier
Audio sense: automatic on/off switching
Switch settable gain
Purifi Eigentakt technology

This product has been replaced by the Arthur 4222/E1 MkII

Faceplate color: Satin Black
Body color: Textured matte dark anthracite
Mains voltage: 180-264V

Purifi Eigentakt technology

For Arthur 4222/E1 we have chosen to implement the Purifi Eigentakt technology. Purifi is the first company to have managed to build a mathematically exact model for self-oscillating amplifiers. This innovation enables a complete optimization of the amplification circuits improving the performance by an order of magnitude over existing implementations.

In more musical terms:
- Highly resolved and stable stereo image across the whole spectrum, even during very complex and busy passages thanks to the negligible inter-modulation distortion (IMD).
- A total lack of sonic signature, and an ability to reproduce any type of music without preference for genre or production style due to the extremely low THD at any frequency and any power level.
- Difficult loudspeakers are handled with ease, including those that challenge most other amplifiers because of the load-invariant frequency response and negligible output impedance.
- The smallest amount of audible artifacts when pushed into clipping or overload is guaranteed by an exceptionally clean clipping and clipping-recovery in both voltage and current domains.

In Arthur 4222/E1, the amplification stage can deliver up to 210 W in 8 Ω and 700 W in 2 Ω

Three stages input buffer with EMI filtering and active common mode rejection

Arthur 4222/E1 input buffer board was designed in-house. The target was to ensure that the amplifier performance would be excellent for both XLR and RCA inputs, the later one being internally called "the pineapple pizza of the audio connectors" due to the disputable effects it has on the audio signal.
The first stage filters out of the signal the disturbances caused by the wireless networks surrounding us. The common mode impedance degradation caused by the filter is cancelled by an elegant bootstrapping technique.
Then two ultra low noise OPA1612 form a differential receiver, also used as gain stage. The same bootstrapping technique as previously is used to dramatically improve the common mode rejection of the stage.
Finally an OPA1632 removes the common mode from the signal in order to supply a perfectly clean signal to the Purifi 1ET7040SA amplifier module.

Three levels gain setting

A switch on the rear of the amplifier allows you to set three different levels of gain. Depending on the output capability of your source (pre-amplifier or DAC with volume control) the system gain structure can be optimized for two main targets.
The first is to have the lowest noise, the second the smoothest volume setting as possible. High gain is optimized for sources outputting 2V, medium for 4V, low for gear able to provide 10 V.
While the noise levels of modern audio gear has become so low that noise optimization for home audio is often purely academic, having a smooth volume control is something we find so enjoyable that it was our main motivation for integrating the gain control switch.

Beautiful chassis, attractive finish

The full aluminum custom chassis is not only nice looking, it dissipates the heat of the amplification module. No screws are visible from front, top and sides. The front plate is machined in an aluminum block and spray painted with different colors that can be chosen while ordering. The top and sides cover is a single piece finished with a special paint, with a matte, suede-like texture providing a very qualitative look and feel.

Listen to the music, forget the electronics

Plug your audio source (with volume control), your speakers, the mains cable, switch on the mains, and forget your amplifier. The automatic on/off function detects the presence of sound at the input and automatically powers on the amplifier. After 10 minutes without sound at the input, the amplifier sets itself in standby, allowing an ultra low power consumption when not in use.
If you are equipped with electronics featuring a trigger function, 12V trigger in and out connectors are also available.

Fully protected

A full set of fault diagnostics allows to protect the amplifier and your speakers against abnormalities.

Designed and proudly built in Luxembourg

Arthur 4222/E1 was designed and is assembled at Schifflange, Luxembourg, at the heart of Europe.

Data sheet

Max power
210 W in 8 Ω
THD+N at 1 W
below 0.001 %
SNR at max power
typ. 126 / 126 / 124 dB
Output noise
typ. 16 / 16 / 19 uV Awt
Frequency response
0 - 60 kHz +0/-3 dB
13 / 20.4 / 29 dB
Minimal load
below 2 Ohm
Input type
Input sensitivity 8 Ohm
9.2 / 3.91 / 1.45 V
Standby consumption
below 0.5 W
Mains cable


Arthur 4222/E1 User Manual

Arthur 4222/E1 User Manual

Download (303.26KB)

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