Controls
- Rate
- controls the speed/rate of the LFO wave that controls the effect
- Blend (on v1)
- controls the mix of dry/wet signal
- Feedback (on v2)
- sets the amount of effected signal fed back into the effect (for a stronger effect)
- Color (on v1)
- ?
- Manual Shift (on v2)
- sets the position of the effect when the LFO is in the center position or controls the effect when the LFO is switched off
- Auto/Manual
- turns the modulation on/off
Information
Electro-Harmonix
The Bad Stone was released 1975 and produced until 1981. It was designed by Bob Bednarz and it was the first phase shifter to employ feedback in the circuitry. It compasses 6 stages of phases shifting with variable feedback. One speciality of this phaser is the manual mode, which lets you dial in the phase shift manually instead of using the LFO (low frequency oscillator). This enables a whole new dimension of sounds achievable, although no sweeping will occur in the manual mode.
Video
(2011-01-15) EHX Bad Stone w/Mk1 Tone Bender by gaedp86
(2011-07-30) late 70s Electro Harmonix Bad Stone Phase Shifter demo by Pacafeliz
(2011-12-18) From the vault: EHX Bad Stone by gaedp86
(2013-12-07) Electro-Harmonix Bad Stone Phase Shifter by blondegraemey
(2016-08-02) Vintage Electro-Harmonix Bad Stone by deniki4
(2017-10-08) Bad Stone, Phase Shifter - Electro Harmonix Demonstration Record, 1977 by adriancopenhagen
Audio
Documentation
- diy project (Topopiccione Electronics)
- mods (by ocoughi aka Anti Bypass, Audiofanzine)
- schematics
- schematics
- schematics (Aron Nelson's Stompbox page)
- schematics (Free Info Society)
- schematics available at Schematic Heaven

