A budget focussed DIY valve/tube headphone amplifier that is so simple it can be easily wired without a PCB. This repository contains circuit schematics/diagrams for a variety of compatible valves/tubes.

There is an amazing array of information out there on the Peter Millet designed Starving Student Hybrid headphone amplifier and various community modifications. This project is an attempt to make it more easily accessible rather than requiring someone to delve into a forum thread many hundreds of pages deep.

I have drafted schematics for the circuits based around the following valves:

Some of the valves share the same pin-outs, but others do not - where they do they've been shown in the same schematic.

So, for example the 12AX7 and 12AU7 have the same pin-out and power requirements so they are both included in ./KiCad schematics/SSMH_12A_7.pro. The same goes for the 12S_7 variants too.

The diagrams were created using the open source schematic editor, KiCad. Whilst it can be a little complicated to learn (it doesn't take too long) it is a powerful circuit designer.

To open the project start with the SSMH.pro file as it should open the project and all sub-projects in KiCad - see ./KiCad schematics.

You are then free to edit the schematic to add components or adjust values against existing components.

Here are a couple of handy little tips that I wish I had known when I was getting familiar with KiCad.

• Command + Scrollwheel pans the schematic horizontally (left/right)
• Shift + Scrollwheel pans the schematic vertically (up/down)

The inbuilt valve libraries were not comprehensive enough so I made two additional symbols and used some from lib_w_vacuum.

• 19J6 by Simon Holywell (me)
• 12SR7 by Simon Holywell (me)
• lib_w_vacuum from http://smisioto.no-ip.org/elettronica/kicad/kicad-en.htm (please see included licence file)