Power Amplifier SE 2A3-45-300B

Power stage designed to be able to work in Single-Ended with the three triodes with the best performance UX4 sockets. On the one hand, the 2A3 valve provides a very defined scene with a dose of great realism, the 45 valve is pure precision and definition, standing out mainly at the vocal level, while the 300B combines high-mids with great detail and bass with more punch.

In essence, they are 3 stages in 1, since each type of valve has been built with its own power supply as well as a different amplification circuit. By means of the frontal selector, values of supply voltage, polarization of valves, filaments and output transformers are switched. With this, it is possible to optimize performance for each of the valves.

Like all power amplifiers designed by dBTronic, it consists of a self-adjusting bias circuit, which varies as the tube ages, as well as 100% stabilized voltages, a separate and internally shielded power supply, and various processes and assemblies that make this stage has optimal response levels and non-existent noise levels.


– Inputs : 2 x RCA

– Input sensitivity (1W) : 2A3: 95mV, 45: 113mV, 300B: 100mV

– Input sensitivity (maximum output): 2A3: 186mV, 45: 141mV, 300B: 275mV

– Signal-to-noise ratio: 2A3: 84dB, 45: 91dB, 300B: 90dB

– Frequency response – 20 Hz – 20 kHz: 2A3: ±0.024dB, 45: ±0.043dB, 300B: ±0.022dB

– Total Harmonic Distortion (THD) – 1W: 2A3: 0.33%, 45: 0.78%, 300B: 0.07%

– Maximum power: 2A3: 3.9W RMS, 45: 1.6W RMS, 300B: 8.8W RMS

– Preamp tubes : ECC81, 2xECC82. Measurements made with MULLARD valves.

– Components : IEC mains connector with antiparasitic filter, 10,000h-105ºC electrolytic capacitors, military quality PIO bypass capacitors, 1% metal film resistors, grain oriented EI power supply transformer, grain oriented EI output transformers with multiple interleaved windings, encapsulated transformers, gold-plated input connectors, gold-plated output connectors: cable up to 16mm2 or banana, ALPS potentiometers and switches, high emission power external heatsink, shielded attack tubes – selected and paired dBT tubes -, feet of decoupling, solders with tin WBT 4% silver.

– Dimensions (mm): 410 x 220 x 370 (W x H x D)

– Weight : 24.2kg (without packaging)

– RRP : €3,618 (VAT included)

– Manufacturer warranty: 3 years