Oatley Electronics K272B prototype

Soon to be released Oatley Electronics K272B prototype. I recently made two CMoy style, OPA2134 based, HP amps but now prefer the better sounding, harmonically rich, K272B build. Two 9V batteries are used in parallel to prolong battery life and switching phone jacks, power switch and “on” LED ensures it is difficult to accidentally leave the amp on. The enclosure is impact resistant ABS which is heavy Al foil lined. Volume control is via your player and the “6418-B” will drive low impedance phones. Where the CMoy style, chip based, HP amps are clean, clear, bright and clinical, the “6418-B” has a much richer, more harmonically complex sound and a smoother all over delivery. Really it all gets down to taste. I would recommend building the K272B when released around early February 2013. I suggest you upgrade the Oatley passive parts and chip socket to better quality parts.

For more info, see the
Oatley K272B JAN6418 headphone amp and preamp thread in the forum.

Mark Houston – retro-thermionic