D-Watt (150115-71)

Single-board mono 200 W Class-D audio power amplifier built from through hole components only. An external power supply is needed (for example SMPS400A400 also available at Elektor).

Specifications:
Measured with the 6/8 Ω version and ±60 V supply voltages (Hypex SMPS400A400), BW = 22 kHz, R7 = 100 kΩ

Input sensitivity:
1.3 V (189 W / 8 Ω, THD+N = 1%)
1.25 V (174 W / 8 Ω, THD+N = 0.1%)

Input impedance: 3.33 kΩ / 11 kΩ

Continuous output power:
174 W into 8 Ω (THD+N = 0.1%, 1 kHz)
189 W into 8 Ω (THD+N = 1%, 1 kHz)
224 W into 6 Ω (THD+N = 0.1%, 1 kHz)
246 W into 6 Ω (THD+N = 1%, 1 kHz)

Power bandwidth: 5 Hz (–3 dB) to 20 kHz (–1 dB)

Slew rate: 15 V/µs (8 Ω)

Rise time: 4.4 µs (8 Ω)

Signal to noise ratio: >77 dB (linear, BW = 22 Hz to 22 kHz)
(reference 1 W / 8 Ω) >80 dBA

Total harmonic distortion plus noise: 0.014% (1 kHz, 1 W / 8 Ω)

(BW = 22 kHz)
0.004% (1 kHz, 50 W / 8 Ω)
0.024% (1 kHz, 1 W / 6 Ω)
0.0046% (1 kHz, 50 W / 6 Ω)

Intermodulation distortion: 0.013% (1 W / 8 Ω)

(50 Hz / 7 kHz, 4:1)
0.023% (50 W / 8 Ω)
0.013% (1 W / 6 Ω)
0.017% (50 W / 6 Ω)

Dynamic IM distortion: 0.037% (1 W / 8 Ω)

(3.15 kHz square wave / 15 kHz sine wave)
0.009% (50 W / 8 Ω)
0.043% (1 W / 6 Ω)
0.008% (50 W / 6 Ω)

Damping factor: 174 (1 kHz, 8 Ω)

Efficiency at full power: 93% with 8 Ω load

(THD+N = 0.1%)
94% with 6 Ω load

DC protection: +3 V / –4 V

DC output offset: <0.3 mV

Switch-on delay: 6 s