"Valvorine" was my first foray into the world of valves. It uses the ubiquitous 12AU7 valve running at low voltage, in this case 12.6v, although technically a hybrid as it is a mix of valve and solid state based on a design by Rogers.
This time I left the amplifier uncased on a plateau of oak. Valvorine was a project with learning and development in mind and as such the amplifier PCB was made in a modular fashion, allowing each section to be disabled independently, and other modules inserted to allow for experimentation.
Modules such as the input/preamplifier and VU Buffer board are separate and have been used in other projects such as 1950's Lego Mindstorm for audio geeks.
The updated design allows for a regulated power supply section, power on delay mute courtesy of the timeless 555 integrated circuit and relay, in addition to a VU buffer for the front-facing level meter to keep it interesting.

Rupert Hirst (2010)

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