Amazon.com: Guitar Mini Effects Pedal Over Drive - Warm and Natural Tube Overdrive Effect Sound Processor Portable Accessory for Guitar and Bass, Exclude Power Adapter Green - FOD3 : Musical Instruments
Amazon.com: Sondery Overdrive Guitar Effect Pedal, Tube Overdrive of A Valve Combo Amplifier Sound - True Bypass, 2 Modes of Boost and Normal - Mini Size, Art Design Series : Musical Instruments
A DIY valve overdrive pedal – Goldie – Dave Mac's Window on the World
The Hagerman Tube Overdrive Pedal - Loaded with a Mullard 12AX7! - YouTube