The latest project to be added to the site is a DIY passive volume control which is made using a switched attenuator. A stepped attenuator operates by switching to different resistors at each of switch settings. The benefit of a stepped attenuator is that it can use low noise metal film resistors making them quieter than typical hot formed carbon and conductive plastic potentiometers. The volume control uses a stereo 100k 24-position stepped attenuator which comes fully assembled for $18US from 8 Audio-Mall. The attenuator uses 1% precision metal film resistors on a “make before break” multi-position switch. A photo of the stepped attenuator is shown below.
|stereo 100k 24-position stepped attenuator|
The stepped attenuator is housed in a small wooden enclosure with aluminum top and bottom plates. A knob, RCA jacks and a 4 Pole Double Throw (4PDT) switch round out the DIY volume control.… Read the full article