Build your own tube preamp / headphone amp for next to nothing

Australian electronics supply Oatley Electronics offers a small, cheap DIY kit to make your own tube preamp / headphone amp.  It's super-simple and low voltage, a perfect starter for anyone who wants to get into DIY tube audio.

It uses two NOS (new old stock) Raytheon JAN6418 tubes, made around 1982, well into the solid-state era.  The 6418's are known as sub-miniature tubes, a tiny family designed to compete with small solid-state electronics rapidly taking over the market.  In addition to being low voltage, the 6418 is readily available as new old stock, costing a mere $1.99 each.

The amp itself runs off of one or two 9V batteries, or optionally AA's wired in series.  Those tiny tubes do emit that famous tube glow, albeit dim, and they do warm to the touch.  The kit includes a preprinted PCB along with everything you need to build a working amp.  It even includes a spare tube, just in case you mess something up.

It's certainly a fun project for a weekend, and it'll add some nice tube warmth the next time you want to listen to your very modern iPod.