The Emotiva BasX A2+ is the two-channel stereo model in Emotiva’s entry-level BasX amplifier series. The BasX range sits below the XPA Differential Reference series in Emotiva’s lineup, offering dedicated amplification stages at a fraction of the cost of the flagship designs. The A2+ shares its fundamental circuit topology with the rest of the current BasX generation — a Class A/B output stage, oversized toroidal power supply, and microprocessor-controlled protection — but packages it in a two-channel configuration aimed at stereo music systems and two-channel home cinema duties.
Circuit Topology and Output Stage
The A2+ uses a Class A/B output stage built around a high-current, short signal path topology. Class A/B operation combines the low-distortion characteristics of Class A at low power levels with the thermal efficiency of Class B at higher output. The amplifier delivers 160 W RMS per channel into 8 Ω (both channels driven, 20 Hz–20 kHz, THD <0.02%) and 250 W RMS per channel into 4 Ω (both channels driven, 1 kHz, THD <0.02%). Damping factor exceeds 500 into an 8 Ω load, and the A-weighted signal-to-noise ratio is greater than 112 dB referenced to rated power.
Microprocessor-controlled protection circuitry monitors the amplifier during operation and intervenes only under genuine fault conditions, leaving the signal path undisturbed during normal use.
Power Supply
The power supply is centred on an oversized toroidal transformer. Toroidal transformers produce lower stray magnetic field radiation than conventional E-I laminated types, reducing the potential for hum induction into sensitive amplifier circuitry. Their lower mechanical resonance also contributes to quieter operation. A bank of Emotiva-branded ultra-low ESR filter capacitors maintains stable voltage rails under dynamic load conditions, supporting the amplifier’s ability to drive 4 Ω loudspeakers without significant output sag.
Inputs and System Integration
Each channel provides one balanced XLR input and one unbalanced RCA input. Balanced XLR connectivity is relatively uncommon at this price point and is valuable when connecting to processors or preamplifiers with balanced outputs, as the differential signalling architecture rejects common-mode noise picked up along the interconnect. Input impedance is 27 kΩ, compatible with a wide range of preamplifier output stages.
A 12 V trigger input (accepting 5–12 V AC or DC) and a corresponding trigger output rated at 12 VDC/120 mA allow the A2+ to switch on and off in concert with a processor or preamplifier. Alternatively, the amplifier can be configured to power up automatically on detection of an audio signal. The unit accepts both 115 V and 230 V mains supplies with automatic voltage selection.
Construction
The chassis is constructed from heavy-gauge steel with a milled aluminium faceplate. The internal layout prioritises a short signal path, minimising parasitic capacitance and inductance. Speaker connections are made via five-way binding posts, accepting banana plugs, spade lugs, or bare wire. Emotiva is headquartered in Franklin, Tennessee, where the company maintains its design, engineering, and service operations.