Turn on/off circuit:
Dave Jones EEVblog #262 - World's Simplest Soft Latching Power Switch Circuit
External 16 to 24 Vdc power adapter.
Pressing the soft latch on/off button turns on/off small Relay that powers the amplifier and ventilation fan.
Components and materials:
Glass dome HÄRLIGA from Ikea was offered from a friend.
All components, wires, pins, connectors are scrap from old electronic equipment taken from local disposal e-bins.
Adjustments, connectors and switches:
— Turn on/off button is an old electrolytic cap.
— Volume control knob is an old electrolytic cap.
— Fan speed is controlled by a variable resistor.
— Audio output connectors from old hifi with outside knobs made of Cupressus lusitanica wood.
— Audio input connector from old CD player.
Ikea HÄRLIGA Dome: 12€
— Base of Ikea wood: Unknown
— Five base wood blocks: Unknown scrap wood
— Tung Oil
+/- Three week's