The U-280 SC Black is an amplifier with unique characteristics. Our proprietary active servo circuit makes the output stage always operate in pure class A without requiring polarization adjustments allowing the change of tubes without any modification. It also allows the use of different valves such as KT88, KT90, KT120, KT150, and 6550, giving the user the possibility to tune the unit to their liking.

The continuous bias adjustment based on the signal rather than the tube characteristics, extends the tube life expectancy, optimizes power consumption, reduces distortion, prevents overheating, improves the damping control and allows the output stage to always operate in a full class A.

The output stage valves can be configured through the simple operation of a selector, such as triodes or pentodes, optimizing efficiency and tonal characteristics.

With its front switches, the amplifier’s impedance, power transfer function, and damping characteristics can be optimized.

The U-280 SC Black can be configured as a monoblock. This allows it to be used in conjunction with another U-280 SC Black increasing its power to double. It also has an input level control per channel that can be used without a preamplifier.

SHUNT power supply.

The power sources of the small-signal stages are independent and of the SHUNT type. This type of source, as it does not have a control loop circuit, does not induce harmonics, thus maintaining the integrity of the audio signal.

The SHUNT source is virtually indestructible thanks to its carefully designed circuitry to guard against common and uncommon bulb failures.

The U-280 SC Black avoids the use of negative feedback, a common practice that results in a loss of detail and richness of sound.

To improve the damping factor without resorting to negative feedback, Margules has developed the BEFS (Back Electromotive Force Sensor) system, which changes the amplifier’s output impedance upon load requirement.

ANA® (Neuro-Acoustic Alignment).

ANA® (Neuro-Acoustic Alignment) technology is a Margules innovation based on the way the human brain perceives sound by prioritizing harmonic structure over the fundamental pitch. This technology is about how we humans perceive sound, not how we measure it.

This technological advance has its origin in the theory of seductive sound (engaging sound), our brain decodes information from sound waves through the ears: when the sounds are close, they keep us attentive due to the relationship that exists between the perception of these, the distance in which we perceive them and their intelligibility. Distant sounds, even when they are intelligible, do not attract our attention and are easily ignored.

Our ANA® technology is designed to achieve realistic sound with appropriate frequency response, low distortion, and accurate harmonic reproduction, optimizing the relationship between source and receiver to the maximum so you can enjoy your music in ways that never before you had experienced.

Power Stereo Ultralinear: 50w / channel

Power mono Ultralinear: 100 w

Power Stereo Triode: 25w / channel

Power mono triode: 55 w

Distortion: > 0.08%

Frequency response: 20-40 khz

Max power consumption: 585 w

Weight: 30.5 kg

Dimensions (height, width, length): 22cm x 45cm x 35cm

MARGULES products are designed and manufactured to last. MARGULES GROUP MEXICO S.A. DE C.V. guarantees free services (exceptions may apply) and spare parts in any country in which an official distributor of MARGULES operates.

Note:

For more information, contact the relevant national distributor.

This warranty complements any national or distributor legal obligations and does not affect your statutory rights as a customer.

This warranty:

It is only valid for products purchased through an authorized MARGULES retailer or distributor.

It is valid only for original products. MARGULES will not return any products you receive for repair if it is determined to be a counterfeit. The sale and distribution of counterfeit products is illegal. It takes effect from the date of purchase and is valid for a period of five years for passive and electronic speakers, one year for amplified speakers, electronic components of wireless reception and digital conversion and 90 days for spare parts (bulbs), with the exception of exclusions applicable in certain countries in accordance with their national laws. Request detailed information from your country’s MARGULES dealer.

It is limited to repairing the equipment (which could be fixed or replaced at our discretion, without affecting the original warranty). The warranty does not cover transport or other costs, nor do it cover risks for the transfer, transport and installation of the products.

It is only valid for the original owner. It’s not transferable.

It will only be valid if they are defective or manufactured materials existing at the time of purchase, and will not be valid in the following cases:

• Due to the deterioration of the parts of its components, which are worn or depleted with use, such as bulbs, sleeves and remote controls.
• Due to interoperability issues with third-party products, unless this purpose is explicitly expressed.
• Due to damage resulting from incorrect installation, connection or packaging.
• Due to damages caused by any incorrect use described in the instructions, negligence, modifications or use of parts that have not been manufactured or authorized by MARGULES GROUP MEXICO S.A. DE C.V.

• Due to damage caused by defective or inappropriate auxiliary equipment.
• Due to damage caused by accidents, electricity, water, heat from fire, war, public disturbances or other causes beyond the control of MARGULES GROUP MEXICO S.A. DE C.V. and its official distributors.
• For products whose serial number has been modified, deleted, deleted or unreadable.
• If repairs or modifications have been carried out by unauthorized persons.

How to request warranty repairs

If you have any questions about the performance of your product, perform the following procedure:

Call the MARGULES dealer in your country of residence. In case of Mexico call MARGULES.

You will find your contact details by clicking “margules.com” at the bottom of the page and selecting the relevant country.

Our representative will clarify all your doubts. If it is necessary to return the product for repair, you may be given a return authorization for the goods. You must not return the product without this authorization, in case it is obtained.

To validate your warranty, you must show the original sales invoice or any other proof that proves your ownership and the authenticity of your date of purchase.