Four 2A3, two 6SN7, two 6SJ7, and one 5Z3P (5U4G) vacuum tubes.
Close-loop voltage gain: 22dB
Overview · Four 2A3, two 6SN7, two 6SJ7, and one 5Z3P (5U4G) vacuum tubes. · The input stage uses pentode 6SJ7 for pre-amplifying and the following stage uses twin-triode 6SN7 for phase splitter.. · The output stage uses two 2A3 tube configured as push pull. Output power can reach 15W for each channel. · Built-in tube (5Z3P/5U4G) and solid-state rectifier and regulation circuitry with two inductors option in CLC filtering. · Two single-end input and two single-end output. · Input sensitivity: 1V RMS · Input impedance: 100K Ohm · Close-loop voltage gain: 22dB · Variable resistor trimmer to adjust plate currents of the output stage tubes. · Support either open loop gain or close loop feedback. · Symmetrical layout design in signal paths for both channels. · Dedicated ground and power rails layout design. · Two large reservoir decoupling capacitors for power rails. · Power requirements: Two 280V/320V AC (100mA), two 6.3V AC (1.5A), two 2.5V AC (5A), and 5V AC (3.5A) · Requires two 25W output push-push transformers with primary winding 3/5KΩ to secondary winding 4/8Ω impedance transformation. · PCB dimension: 198mm (W) x 330mm (L) · PCB thickness: 2.4mm, double layer, 2oz copper.