Posted by
Nov 29, 2021

Swamp Witch Pedals Silver Birch

We love pedals with non-descriptive controls! The Swamp Witch Pedals Silver Birch is a very flexible dual gain stage overdrive voiced after a Sunn Model T amp through a circuit employing CMOs Hex Inverters.

The controls, although non-descriptive, are pretty easy to get: Volume, Gain Stage I (with more of a mid focus) and Gain Stage II (brighter) on the top row and Bass and Treble shelving EQ on the bottom row.

The footswitch on the right switches the relationship of the two gain stages between Parallel and Series: when configured in series, there’s more gain overall and the brighter Channel II is last, tightening up the sound, while in parallel you can get lower gain tube-like drive tones.

Have a listen to the sound of the Swamp Witch Pedals Silver Birch in the videos below.

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.

Electrical Specifications
Switching: relay true-bypass soft-click switching

Input Impedance: 320k? @ 1kHz

Output Impedance: < 5kHz (passive volume control)

Power Requirements: 9V, 50mA

Controls
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.

Channel Order Switch
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.