X251 MKII Integrated Amplifier, solid-state/class AD

A refined and efficient integrated amp, with a real sound ...

Image for illustrative purposes; check the finishes availables with your dealer.

The X251 is the result of more than a decade of R&D and innovation in audio product development by Extraudio engineers and technicians.
The new Extraudio X251 solid-state, modern, analogue integrated amplifier has been developed using our energy-efficient philosophy in the pursuit of the highest standards of honest sound reproduction


The X251 is designed from the Extraudio XP3 preamplifier, which includes the latest Extraudio improvements and innovations.

But not only is the preamplification of the integrated amplifier based on the Extraudio XP3, but this X251 amplifier physically includes the entire section of the XP3 preamplifier. We know that the pitch or character of a high-end audio product is 90% created in its preamp section. At Extraudio, after a rigorous study based on tests and measurements, we have come to the conclusion that creating an integrated amplifier with a small preamp section is not the right thing to do, as it prevents us from experiencing in its true magnitude all the nuances and sensations that musicians want to transmit in their works.

That’s why we included the entire XP3 preamp inside the Extraudio X251, which is built with no compromises or limitations, delivering a sound that is totally real and absolute.

X251 lateral rear

Image for illustrative purposes; check the finishes availables with your dealer.


To this preamp section we added our new high-power EPAM amplifier module, with technology unique to Extraudio, in a philosophy that is premised on high energy efficiency. The result is a natural, fast and powerful sound.

The EPAM amplifier module provides 40 Amps per channel and up to 800W for its two channels at 4 Ohms, with a damping factor of more than 1000, so it can control any type of loudspeaker.


Power supplies are the other key pillar of Extraudio sound. Their ultra-low noise cleanliness and precise audio frequency calculation offer added value. Both factors are responsible for providing the power and life to our audio systems.

The high energy is converted into ultra-low frequencies, and the ultra-low noise level into an out-of-the-ordinary transmission of vocals with very well-defined high frequencies. All this allows us to discover the most exquisite micro details of recordings, which other audio products are not able to express.

X251 front

Image for illustrative purposes; check the finishes availables with your dealer.


The X251 includes our exclusive Extraudio remote control.
This remote control has been conceived with an innovative approach with the user’s convenience in mind. Extraudio sought to offer a device in which battery life and operating distance were its main features. Both objectives have been largely achieved.
The remote control has no removable batteries, but includes an internal battery that only needs to be recharged with a standard USB charger.
The transmission range is 20 to 80 metres, depending on the country in which it is used and the electromagnetic or RF interference present.
The design has a minimalist line, the hallmark of Extraudio’s devices. There are only four buttons: on/off, volume up/down and mute. The concept behind this remote control is unusual, pursuing a more efficient and ergonomic creation.

extraudio remote control


When it comes to the design and aesthetics of the X251 integrated amplifier’s exterior, we are proud to have retained the Extraudio style, minimalist and neutral. Timeless shapes that allow Extraudio equipment to blend seamlessly into any home, be it modern or classic in style.

Likewise, in the chassis we have applied our construction experience based on the use of solid 6000 aeronautical aluminium panels of the highest hardness and quality. This construction provides strength and durability to the product, minimising vibration.

The front aesthetics of the X251 amplifier are simple. On the front panel, apart from the power button, there are two rotary knobs: one for volume control and one for input selection. Linked to the latter are the LEDs with their respective legends, which, when illuminated, indicate the corresponding active input. Everything else is controlled by our software inside the preamplifier.


At Extraudio we base the design of our equipment on the philosophy of Mies Van Der Rohe, who applied the concept of “less is more” to his works.
We eliminate superfluous elements in all phases of the construction process of our products in order to enhance the essential ones.
With this premise, it is easy to understand the sensations that audiophile enthusiasts experience when listening to the X251 integrated amplifier, which can be summed up as “an absolute sound, a more real sound”.

The finish Discovery is High Gloss Black or High Gloss Silver and Silver chromed Knob

“Enjoy your music with Extraudio products”.

Technical Specifications:

2-Channels, Dual Mono and quad power supply.
Frequency Response: 20Hz to 50Khz +0db Flat response
Signal To Noise-Ratio: > 120 dB
(20 Hz – 20 kHz, 8 Ω load)
Dynamic range: > 120dB
THD+N (1kHz @ 1W): 0.003 %
Peak output current: 40 Amp x2
Voltage Gain: 28dB
Gain: (Balanced – Unbalanced) 12db / 6db
Input Impedance:
(Balanced / Unbalanced)
120K / 60K Ohms
Output Power: 800W X2 4Ω / 400W X2 8Ω, Extraudio EPAM amplification modules
Damping factor: > 1000, total channel (8 Ω load, 1 kHz and below)
Power requirements:
115V or 230VAC 50/60Hz, 20W to 300W – 0.5W standby
Ecodesign (ErP) & Energy Star compliant standby consumption of < 0.5W
Safety approved and verified for EMC compliance
(Product W x H x D)
44 x 12 x 40 cm
(Shipping W x H x D)
66 x 66 x 37 cm
(15 kg)
(16 kg) Shipping

Analog inputs:
4 pair unbalanced RCA +0db
1 Pair Balanced XLR -6db
1 Processor AV +0db
(XLR and RCA connectors)
Speakers outputs:
2 Pair Speakers, WBT Germany Speakers Connectors
Internal module Phono preamplifier for cartridge MM or MC, more information.

Assembled, manufactured, and soldered by hand in Europe.

– Pure Class A polarized input stages with BJT transistor technology.
– Frequency response: 20Hz to 20Khz +0dB
– Signal To Noise-Ratio: > 119 dB
(20 Hz – 20 kHz, 8 Ω load)
– Dynamic range:  > 120dB
– Voltage Gain: > 28dB
– Total peak output current: 80 Amp
– Output Power: 800W X2 4Ω / 400W X2 8Ω, Extraudio EPAM amplification modules
– 4 RCA Inputs
  (Optional module phono MM/MC)
– 1 Balanced XLR Input
– Bypass Home Theater (RCA and XLR)
– WBT Germany Speakers Connectors
– Extraudio remote control
– Power supply RMS power limit: 1500W
– EMI and RF anti-interference AC Extraudio input filters

Owner manual X251

These pre-specifications are subject be changed without notice. EXTRAUDIO BV – 2024 (the Netherlands)

Extraudio products are both unique and exclusive, hand-made and long-lasting, beautiful works of art for audiophiles.

Contact us

  • Post mail: Extraudio BV, Gravin Juliana Van Stolberglaan 31, office A8875, 2263 AB Leidschendam, The Netherlands
  • info@extraudio.com


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