PIMETA Headphone Amplifier

PIMETA PCB, crossfeed PCB, and assorted parts

What is a PIMETA?

It’s a PPA-Inspired META42 successor. It’s about the same size as the META42 board, but the topology is closer to that of the PPA.

Features of the PIMETA design:

    • Small board size: 3.0" × 2.4" (76mm × 61mm)

    • The board should work with most FET-input op-amps in DIP-8 and SOIC-8 packages.

    • Burr-Brown BUF634 buffers on the outputs.

    • PPA-like 3-channel setup so return currents from the headphones don’t disturb the signal ground.

    • Reverse power supply voltage protection

    • With low-voltage op-amps, minimum supply voltage is 5 V on a minimal feature set.

    • The op-amps can be biased into class A.

    • The buffers’ bandwidth can be scaled to balance current draw with sound quality.

    • The board will accept either the small and cheap Panasonic EVJ or ALPS RK097/RK098 potentiometers or the nice, big and expensive ALPS RK27 series potentiometer (a.k.a. “Blue Velvet”).

    • All resistors are on 0.100" × 0.300" spacing so you can put a DIP socket in their place and socket the resistors for easy experimentation. Similarly, many other holes are placed on 0.100" centers to allow the use of socket strips.

    • It strikes a careful balance between spaciousness for things like large, premium capacitors, while still keeping the board small enough to fit in small, portable cases like the Serpac H-65.

    • The board’s layout is optimized for minimum trace length and no vias.

Where To Next?


  Project FAQ >>

Updated Tue Jul 01 2008 07:15 MDT Go back to Audiologica Go to my home page