In today’s world of audio technology, it’s no easy task to impress seasoned listeners. And when we at SCIBER entered this field, we had no intention of creating “just another amplifier.” Our goal was to develop a device that would stand head and shoulders above others in its price category. We started from scratch and worked through dozens of circuit design iterations. We paid great attention to industrial design, protective circuitry, and — most importantly — sound quality, which was always our central focus.

So, what did we end up with? Let’s find out together!

First Look

What we have here is a brand-new and exciting device, designed for home use. Thanks to its dimensions, it can be placed not only in a traditional AV rack, but also in tighter spaces — on a shelf, a cabinet, a sideboard, or even in a niche.

The amplifier comes in a sturdy box with a slipcase-style outer cover:

Fig. 1 – Amplifier packaging

Without the slipcase, the box looks clean and stylish:

Fig. 2 – Box without slipcase

Let’s open it up!

Fig. 3 – Amplifier inside the box

Included with the amplifier are: a user manual, a power cable, and four additional interchangeable feet. Our packaging also included a bonus — two 2-meter XLR cables for connecting an audio source. The total weight of the package with the amplifier is approximately eight kilograms.

Appearance and Design

The design of the unit is minimalistic — nothing superfluous. The amplifier has a clean, modern, and refined look:

Fig. 4 – AMPLOI in “Natural Aluminum” finish

The enclosure is made of high-quality anodized (or painted, depending on the finish) aluminum, which not only helps reduce weight slightly, but also provides shielding from electric fields and protects against interference.

The amplifier is available in four color options:

– Natural aluminum

– Black aluminum

– Glossy white

– Glossy black

The package includes a set of short and extended feet. The extended ones are used to better diffuse the light from… the LED music lighting system! Yes — this amplifier features music-responsive lighting. It may seem like a bold choice, but we approached it from an aesthetic perspective, and this is definitely a case where seeing is believing — the effect is captivating and draws you deeper into the music on an entirely new level. Of course, this feature can be turned off.

Construction and Features

Inside, the amplifier is built using a modular architecture — several PCBs, each with its own function. Each channel has its own dedicated amplification board, which, in addition to enabling bridged mode, also provides excellent channel separation. As the input differential amplifier, each mono board uses an OPA1656 op-amp. The output stage for each channel features four LM3886 chips, configured in a composite topology together with an OPA1611. Interestingly, the LM3886 datasheet specifies 0.1% THD at 1 kHz, while the SCIBER AMPLOI delivers less than 0.0005% distortion across the entire audible frequency range (20 Hz – 20 kHz)! In fact, as our measurements will later show, the actual distortion level is even lower — made possible by several proprietary circuit design techniques.

The amplifier’s PCBs use 105 µm copper traces, which is three times thicker than standard. The power rails feature extra-wide traces, ensuring stable current delivery at the declared output power.

For volume control, the device uses a high-quality ALPS RK27 potentiometer from Japan.

Power is provided by two ultra-low-noise, high-quality switching power supplies. While some audiophiles prefer toroidal transformers, we’ve conducted a detailed set of measurements and real-world tests, which clearly demonstrated the advantages of switching power supplies in this application.

(You can read more about those tests here: https://sciber.ru/lab/AudioPSUsCmpr)

Fig. 5 – With the top cover removed

The AMPLOI features an advanced protection and switching module, built using optocouplers and relays. It protects not only the amplifier itself from short circuits at the speaker outputs, but also immediately cuts off the output if DC is detected — preventing possible speaker damage in abnormal conditions. The amplifier also houses a music-reactive lighting module, consisting of a set of seven-band analog filters, a microcontroller, and LED strips.

Controls and Interfaces

On the front panel, you’ll find a volume knob and a power button. The power button also functions as a mode selector for the lighting system:

• Short press: turns the amplifier on and switches lighting modes

• Long press: turns the amplifier off

• Very long press: activates the “On Power Restore” setting

The rear panel includes:

• A switch to select between balanced (XLR) and RCA inputs

• A bypass switch for the volume control (power direct)

• A lighting brightness control button

• A “trigger in” control input

• A ground terminal (M4 screw)

Signal and speaker connections:

• One pair of RCA and one pair of XLR inputs

• One pair of banana-type speaker outputs

Fig. 6 – Rear panel

The front panel of AMPLOI also features a clipping indicator LED. It lights up when the output signal distortion exceeds the manufacturer’s specified threshold — a very practical and useful feature in real-world use!

Protection Systems

To improve overall reliability and user safety, the SCIBER AMPLOI amplifier is equipped with the following protection systems:

• Short-circuit protection at the speaker outputs

You can safely tighten speaker wires onto the terminals without fear of causing damage.

• Speaker protection against DC output

This system prevents damage to your loudspeakers in the event of an internal fault by instantly disconnecting the load if DC is detected at the output.

• Electrostatic discharge (ESD) protection

Protects the chassis and connectors from static electricity.

• Overheating protection

If the internal heatsinks reach 95°C, the amplifier will switch off and the status LED will light up red.

The device will only turn on again once the heatsinks cool down by at least 10 degrees, to 85°C or lower.

• Power supply protection

In case of an overload or malfunction in the amplifier’s power supply section, the device will shut down automatically.

The power indicator will blink red for a short time to signal the fault.

Declared Specifications

• Output Power (stereo mode, 4 Ω): 2 × 110 W

• Output Power (stereo mode, 8 Ω): 2 × 55 W

• Output Power (bridged mode, 8 Ω): 1 × 220 W

• Frequency Response Deviation (20 Hz – 20 kHz): < 0.15 dB

• Frequency Response Deviation (0 Hz – 130 kHz): < 3 dB

• Total Harmonic Distortion (THD) 20 Hz – 20 kHz, 2 × 110 W @ 4 Ω: < 0.0005%

• Intermodulation Distortion (IMD) 20 Hz – 20 kHz, 2 × 110 W @ 4 Ω: < 0.0006%

• Signal-to-Noise Ratio (SNR): < –115 dB

• Damping Factor: > 2000

• Input Impedance: 10 kΩ

Input Sensitivity:

• RCA input: 1.331 V (4.70 dBu)

• XLR input: 2.661 V (10.72 dBu)

Input Sensitivity (Power Direct mode):

• RCA input: 1.996 V (8.22 dBu)

• XLR input: 3.992 V (14.24 dBu)

Gain:

• RCA input: ×16.53 (24.37 dB)

• XLR input: ×8.27 (18.35 dB)

Gain (Power Direct mode):

• RCA input: ×11.02 (20.85 dB)

• XLR input: ×5.51 (14.82 dB)

Maximum Acceptable Input Level (with volume control active):

• RCA input: 6.822 V (18.90 dBu)

• XLR input: 13.643 V (24.92 dBu)

Power Consumption:

• Maximum: 400 W

• Idle / Low Volume: 50 W

• Standby: < 1 W

Dimensions:

• Width: 435 mm

• Depth: 250 mm (215 mm without binding posts and volume knob)

• Height: 115 mm (105 mm with short feet)

Inputs and Outputs:

• Input connectors: XLR (stereo), RCA (stereo)

• Output connectors: Banana plugs (stereo)

Measurements

Test Equipment

For amplifier output loading during measurements, we use the following devices in our lab setup:

Fig. 7 – Load Bank for Testing

This is a load consisting of high-power 1-ohm resistors, which can be configured for 4-ohm or 8-ohm operation.

Our signal generator is a device by RIGOL:

Fig. 8 – Signal generator

Oscilloscope: OWON

Fig. 9 – Oscilloscope

DAC/ADC: Lynx Hilo

Fig. 10 – DAC/ADC

Attenuator:

Fig. 11 – Attenuator

We also used a computer running RightMark Audio Analyzer 6.4.5 PRO, SpectraPlus, and a true RMS voltmeter for the measurements.

Process

Let’s get started!

Power Output

We begin by measuring the amplifier’s actual output power.

A 4-ohm load is connected to each channel. We power on the signal generator, connect the oscilloscope, and gradually increase the volume until we observe clipping — when the sine wave becomes visibly flattened at the top and/or bottom. It’s worth noting that the clipping indicator LED turns on slightly before the oscilloscope shows actual clipping. This is intentional — the clipping threshold is factory-calibrated with a small margin of safety. We then connect a true RMS voltmeter to the amplifier output to take a reading.

With a 4-ohm load, we measure URMS = 22.4 V.

Using the formula PRMS = (URMS²) / R, we calculate: 22.4² / 4 = 125.4 W, which exceeds the rated 110 W per channel at 4 ohms.

Now we repeat the test with an 8-ohm load: URMS = 22.9 V, which gives: 22.9² / 8 = 65.5 W — again exceeding the specified 55 W per channel at 8 ohms.

This extra headroom is intentional — it ensures the rated specs are guaranteed under all normal conditions.

Bridged Mode Power Output

The AMPLOI also supports bridged mode, in which the amplifier operates as a single-channel (mono) unit with significantly higher output power. To enable this mode, a special adapter and a jumper are used. Here’s what it looks like:

Fig. 12 – AMPLOI in bridged configuration

The amplifier is officially rated for bridged operation with an 8-ohm load,

but we decided to test it with 4 ohms as well.

Measuring Output Power in Bridged Mode

Let’s start with the 8-ohm load.

We measure URMS = 44.3 V.

Using the formula:

44.3² / 8 = 245.3 W — once again, above the rated 220 W!

Now for the 4-ohm load:

While increasing the volume, we were unable to reach pre-clipping levels on the oscilloscope —

the amplifier’s current protection kicked in when the output reached URMS = 33.7 V, shutting the device down.

However, at URMS = 33.5 V, the amplifier operated without issue.

So, we’ll use this as the basis for our calculation:

33.5² / 4 = 280.5 W

This is the sustainable output power the amplifier can deliver to a 4-ohm load in bridged mode.

So yes, the amplifier can drive a 4-ohm load in bridged mode, though with some limitations due to current protection.

As we can see from these results, the measured output power exceeds the manufacturer’s specifications — across all test scenarios.

Distortion Measurements (THD, IMD, Frequency Response)

Now we move on to measuring the amplifier’s signal distortion levels.

The amplifier is set to operate at maximum output power just below clipping, and is connected to a measurement PC via a Lynx Hilo DAC/ADC.

The signal path is fully balanced from the DAC to the amplifier,

and the amplified signal is fed back into the ADC through an attenuator.

We launch the test suite and run measurements with the AMPLOI connected to both 4-ohm and 8-ohm loads, on both channels.

We also performed loopback measurements of the Lynx Hilo (output into its own input) and included them in the result table for comparison.

(Since we used only one channel of the Hilo for testing, we only provide single-channel data for the interface.)

Fig. 13 – Measurement results

We observe extremely low distortion levels — no higher than those of the signal source itself!

Below are the resulting THD graphs of the amplifier under 4-ohm and 8-ohm loads, as well as the distortion graph of the signal source:

Fig. 14 – THD for left and right channels with 4-ohm load

Fig. 15 – THD for left and right channels with 8-ohm load

Fig. 16 – THD for one amplifier channel at 4 and 8 ohms vs. THD of the Lynx Hilo itself

The graphs confirm that AMPLOI’s distortion levels are no higher than those of the Lynx Hilo. Next, we present intermodulation distortion (IMD) graphs using the 60 Hz + 7 kHz test signal:

Fig. 17 – IMD 60 Hz + 7 kHz for left and right channels with 4-ohm load

Fig. 18 – IMD 60 Hz + 7 kHz for left and right channels with 8-ohm load

Now let’s take a look at the frequency response (FR) graphs:

Fig. 19 – Frequency response with 4-ohm load

Fig. 20 – Frequency response with 8-ohm load

The frequency response is virtually flat, with only a slight drop of –0.15 dB at 20 kHz (which corresponds to about a 1.74% decrease in voltage at that frequency).

This roll-off is due to the RF interference filter used at the amplifier’s input. The filter helps eliminate intermodulation distortion within the audio frequency range caused by interference from various household devices (such as mobile phones, Wi-Fi, LED lights, etc.).

Pulse Response

Let’s now perform another test — the pulse response. This test involves feeding the amplifier with square wave signals. Ideally, the output should replicate the square shape — and we can verify this using an oscilloscope.

If the output signal deviates from a square wave, the test is essentially considered failed. Since the spectrum of a square wave contains all odd harmonics, distortion in its shape indicates frequency-dependent propagation speed through the amplification path — essentially meaning the signal is being smeared or degraded.

Additionally, in poorly designed circuits, square waves can cause ringing or overshoot at the wave edges, and in some cases, even self-oscillation.

We’ll perform this test using a passive 4-ohm load (see Fig. 7) at 1 kHz, and also using a complex load in the form of Monitor Audio Silver RS8 speakers at 100 Hz, 1 kHz, and 20 kHz.

So, let’s connect the signal generator and oscilloscope and see how AMPLOI handles it.

Fig. 21 – Amplifier response to 1 kHz square wave with 4-ohm passive load (blue – input signal, yellow – output signal)

Fig. 22 – Amplifier response to 100 Hz square wave with complex load (blue – input signal, yellow – output signal)

Fig. 23 – Amplifier response to 1 kHz square wave with complex load (blue – input signal, yellow – output signal)

Fig. 24 – Amplifier response to 20 kHz square wave with complex load (blue – input signal, yellow – output signal)

As we can see, the output signal closely tracks the input without distortion or instability, confirming that the Sciber Amploi handles even challenging signals with ease and exhibits no performance issues.

Fig. 25 – Square wave test with complex load (Monitor Audio Silver RS8)

(Apologies for the clutter in the photo — the test was conducted shortly after moving into a new space, and we hadn’t yet had time to organize everything.)

Noise Spectrum

Now let’s examine the amplifier’s noise floor. We connect termination plugs to the inputs to eliminate any interference from signal cables, and take measurements for each channel across a frequency band from 20 Hz to 40 kHz. We measure in both volume bypass and volume control modes, using both XLR and RCA inputs.