Selector Switch & Volume Control

The Selector Switch & Volume Control is a two-part circuit board intended for use with the Input Selector. It is sold as a panel and consists of two boards separated by a V-score:

1. Volume Control: A simple volume control board that supports the use of an ALPS RK271-series "Blue Velvet" potentiometer. The connections to the volume pot are provided on a gold-plated, 10-pin connector. The routing is optimized for high signal integrity, including excellent channel separation.
2. Selector Switch: This board is intended for use with the C&K and Lorlin brand rotary switches. The Selector Switch allows for up to six settings on the rotary switch, but many DIYers will want to customize the number of settings. Thus, I have designed the Selector Switch to allow for three to six positions on the rotary switch, while maintaining a symmetrical layout of the switch and the indicator LEDs. This allows for an aesthetically pleasing front panel design. 

The design documentation for this circuit board includes a drill template. Using the template will ensure the correct location of the switch and LEDs for configurations with 3, 4, 5, or 6 indicator LEDs.

To separate the two boards in the panel, simply snap the panel along the V-score.

Technical Documentation

Design Documentation

• Features
• Specifications

• The features of the Selector Switch are listed below.

  • Max. number of switch settings configured by wire links. 
  • Supported switch settings: 3 – 6.
  • Indicator LEDs placed at 25.4 mm (1.0") from switch centre with option for placement  38.1 mm (1.5") from switch centre as well.
  • Indicator LEDs are arranged symmetrically for all four supported switch configurations for best aesthetics. 
  • Intended for mounting by the switch threads, though, mounting holes are provided as well.
  • Gold plated PCB. Made in Canada.

  The features of the Volume Control PCB are shown below.

  • PCB optimized for use with the ALPS RK271-series "Blue Velvet" volume pot.
  • Routing optimized for high signal integrity. 
  • Separate ground plane for left and right channels for best channel separation.
    
  • Connector pinout optimized for high signal integrity, including high channel separation. 
  • Gold plated PCB. Made in Canada

  The parts budget for these two circuits is approximately $44 with the majority of this cost consumed by the ALPS volume pot ($19) and the rotary switch ($16).
  

• The specifications for the Selector Switch are listed below.

  Parameter	Value	Notes
  Number of switch positions	3 – 6	Configured by jumper option
  Power Supply Voltage	5.0 V
  Power Supply Current	3 mA
  Assembled Dimensions	58 × 37 × 34 mm	Not including switch shaft
  Assembled Weight	32 g

   

  The specifications for the Volume Control PCB are tabulated below.

  Parameter	Value	Notes
  Assembled Dimensions	28 × 37 × 38 mm	Not including potentiometer shaft
  Assembled Weight	40 g