All photos are the actual pedal. No box or manuals.
From Swamp Witch:
The Silver Birch is an overdrive with distortion-capabilites that rose from the moonlight, inspired by a number of Model-T clones. From tip to bristle, this dual channel overdrive uses CMOs Hex Inverters to acheive a tube-like sound. Warm and round. Boomy and haunting. Rich and cutting. The options are limitless.
Volume: Make it softer or louder
Channel I Gain: Adjust the gain for the low/midrange channel
Channel II Gain: Adjust the gain for the bright channel
Lows: Post-gain, cut or boost lows
Highs: Post-gain, cut or boost highs
Bypass Switch: Turn it off and on again
Channel-order Switch: Switch between Parallel and Series gain channels. In series, Channel II (bright) is last, tightening up the sound.
In Parallel mode, both Channel I and Channel II contribute equally to the pre-equalizer tone. Boosting Channel I gives more lows, and Channel II gives more high-mids and highs.
In Series mode, Channel I is used as a pre-amp for Channel II. This means the Channel II gain setting controls how big and loud the Series mode sounds. With Channel II gain turned down, tone focused into a tight, muted sound --- with Channel II gain turned up, the Silver Birch opens into a mean, huge howl of distortion.