Eversolo AMP-F8 Stereo-Amplifier

Eversolo AMP-F8 Stereo-Amplifier

AMP-F8

The Eversolo AMP-F8 is a Class AB stereo power amplifier designed for building or expanding a high-quality two-channel system. It delivers ample output power with low distortion and is designed to drive a wide range of speakers, from compact bookshelf speakers to large floor-standing speakers with complex impedance.

Output Power and Drive

In stereo mode, the AMP-F8 delivers 180 W RMS per channel into 8 Ω and 280 W RMS per channel into 4 Ω. A switch on the rear panel allows the amplifier to be set to bridge mode, in which it delivers up to 500 W RMS into 8 Ω; operation at 4 Ω is not supported in bridge mode. The available power reserve supports controlled bass reproduction and ensures stable drive even with more complex speaker impedances.

Power Supply

For its power supply, the AMP-F8 uses a specially developed 800-W toroidal transformer that powers both channels independently. This reduces crosstalk between the channels, which has a positive effect on channel separation and control during dynamic signal peaks. In addition, 24 audio-grade filter capacitors are used to reduce residual ripple in the power supply and support current delivery during brief load spikes. An integrated DC-blocking circuit reduces the influence of DC components in the mains power on the toroidal transformer, thereby counteracting mechanical vibrations and potential noise.

Distortion and Signal-to-Noise Ratio

The total harmonic distortion plus noise (THD+N) is 0.003% at 1 kHz, and the signal-to-noise ratio is ≥ 115 dB (A-weighted). A low total harmonic distortion combined with a high signal-to-noise ratio contributes to clear reproduction of fine details and a quiet sonic background, especially at low volumes or during quiet passages.

Circuit Design

To amplify low signal levels, the AMP-F8 employs a dual-differential amplifier architecture with a balanced circuit design and precise negative feedback, which reduces common-mode noise and external interference. Each channel also features three pairs of precisely selected high-current MOSFETs connected in parallel, which distributes the current flow more evenly and maintains linearity even under varying load conditions. With a damping factor of over 400 (at 8 Ω, 1 kHz), the amplifier is designed to provide firm control over the speaker cone, which is particularly noticeable with large bass drivers.

Connections and Operating Modes

Each channel features a balanced XLR input and an unbalanced RCA input, between which you can switch via a selector switch. Another switch allows you to adjust the input sensitivity to 23 dB or 29 dB of gain, depending on the sensitivity of the connected speakers. A selector switch allows you to toggle between stereo and bridged modes. Power can be turned on and off either manually via the standby button, via a 5–12 V trigger signal from an upstream device, or automatically via signal detection; if no input signal is present, the amplifier automatically switches to standby mode after approximately 20 minutes.

Housing and Operation

The housing consists of a CNC-machined aluminum unibody with a sandblasted anodized finish. The solid metal construction helps suppress chassis resonance while also aiding heat dissipation and electromagnetic shielding; cooling is achieved passively via natural convection, without a fan. Two analog VU meters display the level in real time; their backlighting can be turned on or off using a dedicated switch. A two-color LED ring on the standby button indicates the operating status (white: on, orange: standby, alternating orange/white: protection mode), and built-in protection circuits against overcurrent, overtemperature, and short circuits ensure safe operation under various conditions.

Specifications

General

• Product Name: AMP-F8
• Device Type: Stereo Power Amplifier
• Amplifier Class: Class AB

Output Power

• Stereo Mode: 180 W RMS per channel at 8 Ω
• Stereo Mode: 280 W RMS per channel at 4 Ω
• Bridge Mode: 500 W RMS into 8 Ω (4 Ω not supported in bridge mode)
• Test Conditions: AC 120 V / 240 V

Audio Specifications

• Total Harmonic Distortion plus Noise (THD+N): 0.003% at 1 kHz
• Signal-to-noise ratio (SNR): ≥ 115 dB, A-weighted
• Frequency response: 10 Hz–30 kHz, ±0.5 dB (at 1 W/8 Ω)
• Damping factor: > 400 (at 8 Ω, 1 kHz)
• Channel separation (crosstalk): ≤ −95 dB (at 180 W/8 Ω, 1 kHz)

Inputs and Sensitivity

• Inputs: 1× balanced XLR and 1× unbalanced RCA per channel, switchable
• Input impedance: XLR 10 kΩ, RCA 10 kΩ
• XLR input sensitivity: 5.2 V at 23 dB gain / 2.6 V at 29 dB gain
• RCA input sensitivity: 2.65 V at 23 dB gain / 1.3 V at 29 dB gain
• Test conditions: 180 W at 8 Ω, 1 kHz

Power Supply, Dimensions, and Accessories

• Mains voltage: 100–120 V / 60 Hz or 220–240 V / 50 Hz (switchable)
• Maximum power consumption: 1200 W
• Dimensions (W × D × H): 265 × 388 × 119 mm
• Net weight: 15.9 kg
• Gross weight: 18.6 kg
• Package contents: 1× power cord, 1× trigger cable, 1× user manual

Controls and Connection Panel

• Standby button with two-color LED status ring (white: operating, orange: standby, alternating orange/white: protection mode)
• Sensitivity/gain switch: 23 dB or 29 dB
• Stereo/bridge mode switch
• Standby control: 5–12 V trigger input or automatic signal detection
• VU meter backlight on/off switch
• Voltage selector switch 115 V / 230 V (bottom of unit)
• Speaker outputs for left and right channels (screw terminals)
• Ground terminal