1. volume control

requirements to the volume controller:

  • the playback volume level needs to be user adjustable.
  • the loudness character should equal the human feeling of linear volume steps, which behaves roughly logarithmically.
  • since the signal quality of playback is affected immideately, the volume controlling process needs to be as neutral and exact as possible.
  • for stereo or multi-channel home cinema two or more channels are required to be adjusted in synchronicity.

2. source selection

requirements to a source selector

  • connection of wanted signal inputs with the designated signal outputs
  • signal routing of the signal within the preamplifier
  • since the switching devices directly control the signal path, the process should run as neutral and exact as possible.

3. and 4. amplification, matching and signal handling

requirements of the amplification:

  • adjustment of the levels of currents, voltages with regard to their amplitude- and phase-relationships at the inputs und outputs.
  • matching of input- and output impedance values