Overview
· Use 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 280/320V AC (100mA), two 6.3V AC (1.5A), two 2.5V AC (5A), and 5V AC (3.5A)
· Requires two 15W 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.
Pre-Amplifiers
