Dynavox X7000
audio mains filter - black - Dynavox

Any hi-fi system is only as good as the electricity that powers it. What the power supplier delivers as a 230-volt sine wave is in practice a mixed signal full of high-frequency interference and mains feedback from switching power supplies, dimmers, LED lamps, WLAN routers and refrigerator compressors. The toaster doesn't care - the power supply unit of a high-quality amplifier, DAC or phono amplifier does. High-frequency interference on the supply voltage can be directly reflected in the sound: as an increased background noise level, as a narrower stage, as a loss of fine details. The Dynavox X7000 addresses precisely this weak point and supplies the system with purified power - with the consistent silence that high-quality audio components deserve.

The X7000 is the successor to the proven X6000 and supplements its filter function with an informative display for mains voltage and power consumption of the connected components. It has the housing format of a 19-inch rack unit in a 2U profile, weighs 6.15 kg and processes up to 10 amps - enough for complete high-end systems including power amplifier. The robust 8 mm front panel made of brushed aluminum positions the X7000 visually at eye level with the devices it supplies.

A hi-fi mains filter works in two ways: it stops interference from the general supply network before it reaches the power supply units of the audio components - and it prevents digital devices from feeding their own switching pulses into sensitive analog circuits via the common current path. In particular, switching power supplies of modern digital devices such as streamers, DACs and routers generate high-frequency interference voltages that spread via the mains and also leave audible traces in neighboring devices. Many users are familiar with the result: a slight background noise that covers the sound image like a veil, or a stage that never quite wants to go into the depths.

User reports on the X7000 - some of them from skeptics - describe measurably better stereo imaging after connection: Instruments become more localizable, the stage gains depth and compactness. Especially with systems that have problems with transformer hum or DC components in the mains, a mains filter can make the difference between an annoying background noise and a quiet, relaxed listening experience. Important: High-quality power amplifiers with toroidal transformers and high pulse current requirements benefit from being operated on the two unfiltered sockets - conventional mains filters increase the mains impedance, which can limit the dynamics of power amplifiers. Source devices, preamplifiers and DACs, on the other hand, should be connected to the four filtered sockets.

The correct phasing is one of the most basic and most often overlooked settings on a hi-fi system. In a Schuko socket outlet, the plug orientation is theoretically irrelevant - but not in practice. If a device is connected to the mains with the wrong phase position, capacitive coupling can cause measurably higher interference voltages to build up on the housing and thus on signal grounds. The result is increased noise and a less transparent sound. The phase LED on the X7000 immediately indicates whether the polarity of the supply cable is correct. All six output sockets are also marked with L (phase) and N (neutral) - so that every connected device can be plugged in with the correct phase, which makes an audible difference, especially with non-earthed components such as many CD players and DACs.

With a weight of 6.15 kg and the exact 19-inch dimensions (430 × 100 × 305 mm), the X7000 is just as suitable for rack installation as it is for use on a rack shelf. The housing is made of sturdy steel, the front is made of an 8 mm thick brushed aluminum panel in black - a finish that blends seamlessly into any black rack structure. The built-in 10 A automatic fuse protects the connected system in the event of an overload without the need to replace an external fuse. The device is supplied with a 1.5 m cold appliance cable - if you want to go one step further in terms of sound, you can replace this with a high-quality audio cable, as the input is designed as a standard cold appliance socket (IEC C14).

The display - the decisive advance over the predecessor X6000 - shows the current mains voltage or the total power consumed by the system in watts on request. If you don't need the display or don't want any distractions in the listening room, you can deactivate it completely. The X7000 reliably remembers which mode it was last operated in - no reconfiguration is necessary the next time it is switched on.