Soulnote A-2 is a very simple, high speed, perfectly balanced non-NFB amplifier with just adding an input selector and an attenuator to the power amplifier.
“It is an integrated amplifier equipped with various monaural modes such as a new type of BTL / bi-amp and a power amp mode. BTL does not use left and right channels. By sing a balanced amplifier with only one side channel it becomes a mono BTL differential amplifier with pure tone quality.”
The attenuator is a method of switching high precision resistors with relays.
Input terminal, selector, relay type attenuator, non-NFB balanced voltage amplifier, up to the shortest place on one PWB.
Output stage. The power transistor and power supply capacitor are connected by a thick copper foil of 70 μm.
4 parallel power transistors are screened and matched.
Internal layout
Square wave response. 100 kHz !! It is possible because it is a complete non-NFB amplifier.
Mode switch.
■ Specifications
– Output 100 W × 2 (8 Ω), 200 W Ũ 2 (4 Ω), 400 W (BTL MONO 8 Ω)
– Total harmonic distortion factor 0.03% (50 W 8 Ω)
– Frequency characteristics speaker (8 Ω 1 W): 3 Hz to 240 kHz (± 1.0 dB)
– Input sensitivity / impedance LINE 1, 2, 3 (balance): 700 mV / 16 kΩ, LINE 4, 5, 6: 700 mV / 8 kΩ
– S / N ratio 110 dB (IHF A network)
– Power supply voltage AC 100 V 50/60 Hz
– Power consumption 355 W (J60065), 125 W (idling)
– Maximum external dimensions Body: 430 (W) x 160 (H) x 410 (D) mm
– Weight Approximately 20 kg