A portable Triode Headphone Amplifier is rather a unique piece of gear for a world which is solid state and integrated chip driven. But this very warm and musical sounding preamp is truly portable relying on two 9V lithium batteries for its energy.
The circuit is based on the Oatley Electronics K272 triode preamp kit. There are many upgrade components added to the original kit. The input comprises two JAN6418 sub-mini pentodes in triode mode. The output is buffered by a PT2803 OP amp driver chip. This chip is a low distortion headphone driver/amplifier but here is used with unity gain. It has sufficient power to drive low impedance headphones.
Coupled with your iPod or more high performance portable player, this Mongrel Dog Audio headphone amp provides a unique and intoxicating listening experience. Compact and not too heavy for daily use and with a battery life of hundreds of hours there is now no excuse not to listen to your fav. music with the full tone it had been recorded.
