Naiu Laboratory Ella Mark 3 Class ND Stereo Amplifier

At the beginning there was the vision of developing an amplifier capable of amplifying arbitrarily fast signals without altering them.

In order to comply with this idea, we had to break the set in stone rules of the audiophile world and adopt a new path.

By analyzing a music signal in a purely scientific way, it was very fast clear that the bandwidth of an amplifier had to be considerably larger than the range of audible frequencies of about 20 kHz assumed for humans. It is only possible to ensure that almost no alteration and only minimal phase shifts between input signals and output signals in the audible range and far above it (200kHz) occurs by providing a very high power bandwidth of at least 1 MHz.

An amplifier has to operate extremely fast in order to avoid an alteration of the high-frequent music components. Hence, a very short signal rise time had to be accomplished.

It was impossible to implement these requirements in the established amplifier technologies because the power transistors were destroyed in the presence of high frequencies, due to unavoidable component differences, temperature dependent shift of characteristic curves and unavoidable minimally different transistor switching times. Furthermore, the requirement of energy efficiency of these days had to be considered.

In order to eliminate these problems it was necessary to develop an intelligent concept fulfilling the requirements with respect to power output and power bandwidth. The aim was to unify the advantages of the class A technology as well as the class D technology without their disadvantages. Certainly, this sounds trivial and logical but it took years of fundamental research until this aim was accomplished. A patented circuitry was the result, which doesn’t fit in any established matrix.

This was the same with our Revolution technology of 1995. Because there was nothing adequate, we just called it class N as abbreviation of class Naiu. Mircea Naiu is the inventor of the class N technology as well as the current technology of ELLA ®. Accordingly, class ND stand for class Naiu Digital.

With this patented circuitry the company Naiu is capable of manufacturing amplifiers meeting the requirements of amplifying a signal with undistorted purity.

With our amplifiers we set new standards with respect to power bandwidth, phase precision and stability of sound.

ELLA reaches the tonal advantages of the class A technology with an efficiency of around 80% which resides in the area of pure class D amplifiers.

Apart of that we have made ELLA absolutely resistant against short circuits at the output connectors.

Not only for the few... we build devices for people with a sense of the special. For people who look into the future, knowing exactly what is vital.

Technical Data

• Output power:
  2 * 400 W - sine effective at 4 ohm
  2 * 800 W - sine effective at 2 ohm
  Small signal bandwidth (out±5Vpeak/4ohm)
  > 1 MHz (measured without input filters)
• Damping factor: > 800
• Distortion (THD + N): < 0.0056 %
• Input sensitivity for full scale level: ± 2.25 V peak
• Input impedance: 20 k ohm (DC)
• Power consumption without signal: 27 W
• Peak power consumption: 2500 VA
• Mains voltage: 230 or 115 V
• Phase shift at 20 Hz: < 0.00020°
• Phase shift at 20 kHz: < 0.030°
• Propagation delay: < 40 ns
• Phase shifts and delay: calculated at 200 KHz
• Weight: 20 kg / 44 lbs
• Dimensions (W x H x D): 440 x 325 x 110 mm (17.23 x 8.46 x 4.33 inch)