503HTA - Hybrid tube Amp - Volume Knob

This is a knob for my 503HTA Hybrid tube amp, from Pi2 design; http://www.pi2design.com/store/p13/503HTA_-_Hybrid_Tube_Amp.html

As wide a knob as reasonably fits on the amp without blocking the adjacent attenuation switch.

A full 20mm of depth gives your fingers lots of easy to grip surface. Large flat corresponds to the knob flat to visually indicate volume level.

UPDATE: I've added a version 2 of the knob. This is the same basic design, with more knurls on the outside, and some o