2 input Mixer, Output selector

Custom 2 input Mixer with Output selection and isolation.
This is a 2 input Mixer equipped with two independent outputs (A,B). Additionally, the B-Output is isolated through an audio transformer in order to avoid any ground loop noise when connecting the outputs into different amps or other devices.
A rotary switch allows you to select which output is active each time and also offers a “mute” position where both outputs are silenced.
The mixer can handle instrument level signals as well as line level signals (unbalanced). If you ever need more headroom you can increase the power supply voltage up to 24V.
 
Specifications:
  • Input Impedance: 10MΩ
  • Output Impedance: 100Ω
  • Inputs 1-2 and output-A have common ground
  • B-output is isolated through an audio transformer.
  • 4 position Rotary switch: (Mute), (A), (B), (A & B)
  • Voltage Required: DC 9-24 Volt
  • Polarity: center negative
  • Max Current draw: 14mA (@ 9V)
  • Headroom vs power supply: ~7Vpp@9V | ~10Vpp@12V | ~22Vpp@24V