WSH 605 - integrated amplifier
black - Unitra

Integrated amplifier - high-end stereo

There are amplifiers that play music - and there are amplifiers that bring music to life. The Unitra WSH-605 belongs to the second category. Developed and manufactured in Warsaw, it combines the design heritage of the Polish hi-fi legend Unitra with an amplifier technology that is unique in the world: a patented error correction technology directly in the power amplifier that makes classic feedback circuits superfluous and eliminates sound distortion at the root. The result is a sound experience of exceptional purity - dynamic, natural and uncompromisingly honest to every recording.

Unitra is not a newly founded brand, but a return: Founded in 1961 as an umbrella organization of Polish consumer electronics manufacturers, Unitra was present in almost every Polish and Eastern European household for over three decades - and even produced on behalf of Sanyo. After the political change in 1989, the brand disappeared until it was revived in 2021 by a team of passionate engineers under the motto "Engineering as timeless beauty". The WSH-605 is an expression of this aspiration: built to last for decades and designed for music lovers who accept no compromise between technology and emotion.

The all-metal housing of the WSH-605 sends a clear message: no expense has been spared here. The brushed aluminum front panel features finely engraved lettering - no icons, no color gradients, no distractions. Large, solid-looking rotary controls for volume, balance and bass and treble control offer a haptic quality that is hard to find today. The characteristic retro-style toggle switches complete the picture: a device that is intuitive to operate and makes a statement with its mere presence.

A special detail: the switches on the front panel also react physically in remote control mode - they actually move. This design decision requires engineering effort, but brings back something invaluable: the feeling of interacting with a real device, not a user interface. Unitra has deliberately designed the WSH-605 to be repairable - a philosophy that seems almost revolutionary in today's throwaway culture.

The heart of the WSH-605 is its patented Gain Error Correction - according to the manufacturer, the world's first series device to implement this technology directly in the power stage output. The principle is as elegant as it is effective: the system continuously compares the amplified output signal with the input signal before the output stage. Any deviations detected - whether harmonic distortion, intermodulation artefacts or other non-linearities - are calculated and fed back into the opposite phase at the input. This global correction covers the entire signal path, not just a partial range.

The decisive difference to classic feedback circuits: Conventional feedback circuits attempt to subsequently smooth out errors that have already occurred - with the familiar side effect of phase-delayed correction signals that sometimes dull rather than brighten the sound image. The WSH-605's gain error correction, on the other hand, acts precisely and in real time. The result is directly reflected in the measured values: a distortion factor of less than 0.0008 % at 60 watts and a damping factor of over 240 at 1 kHz / 8 ohms - values that are well above the class average.

The WSH-605 is consistently designed as the universal heart of a modern hi-fi system. The phono MM stage serves vinyl enthusiasts with clean, color-neutral amplification - tried and tested, without superfluous character. Four digital inputs (2× optical, 2× coaxial) enable the direct connection of CD players, streaming devices or televisions. The built-in ESS Sabre DAC processes PCM signals up to 192 kHz / 24-bit and thus covers all Hi-Res formats of common streaming platforms. Particularly valuable: the jitter suppression of the ESS chip also stabilizes signals from sources with high jitter - such as consumer televisions or set-top boxes.

The balanced signal routing between the rear inputs and the front panel minimizes interference on the internal signal path. If you want to integrate a subwoofer or operate an external power amplifier, you can use the fully-fledged pre-out - volume, tone control and balance remain active. A remote control is included and, in addition to volume and source selection, also allows you to adjust the sound from your listening position without having to get up.

The international trade press unanimously describes the WSH-605 as an amplifier of exceptional transparency: a sound image of crystalline purity that presents recordings as they are - without artificial gloss, without warm coloration, without dramatizing exaggeration. The low bass is clear and contoured, without exaggeration; the mid-range reproduction - the decisive frequency band for voices and instruments - works unagitatedly and with high resolution. The WSH-605 is the ideal partner for anyone who wants to experience music rather than stage it.

The integrated headphone amplifier is not a compromise module, but an independent, dedicated circuit for headphones with low to medium impedance. It delivers stable performance, optimum control and the same level of detail resolution as the speaker path. Connecting a pair of headphones automatically mutes the speaker outputs - without any further operation.