
BAD STONE
Congratulations on your purchase of the Bad Stone, a reincarnation of the highly sought
after Electro-Harmonix classic from the ‘70s, now in a nano package. The Bad Stone is a
six stage phase shifter with variable rate, feedback, and a manual shift control that allows
you to freeze the phase and create new sonic landscapes. True bypass switching ensures
your tone won’t be colored when the pedal is bypassed.
RATE Knob – Controls the Bad Stone’s modulation speed by setting the frequency of the
internal low frequency oscillator (LFO). The speed ranges from 0.05Hz to 32Hz. (Note:
The original Bad Stone’s LFO frequency range was 0.2Hz to 32Hz. We felt that altering the
original design to allow for slower phasing, thus making this pedal not a 100% true
reissue, made for a better overall product.) This control is disabled when the
AUTO/MANUAL toggle switch is set to MANUAL mode.
FEEDBACK Knob – Controls the amount of signal fed back from the output of the phase
shifter circuit into the input of the phase shifter circuit. As you turn the feedback control
up, the phase shift effect will sound more pronounced and even sound resonant or “peaky”
at high settings.
MANUAL SHIFT Knob – Sweeps through the phase shifter’s range, creating a sort of
“cocked wah” sound. For maximum effect, make sure the FEEDBACK knob is in its full CW
position. This knob is only active when the AUTO/MANUAL toggle switch is set to MANUAL
mode.
AUTO/MANUAL Switch – In AUTO mode the Bad Stone’s LFO modulates the phase
shifter. In MANUAL mode the LFO is disconnected and the MANUAL SHIFT knob sweeps
through the full range of the phase shifter.
INPUT Jack – This ¼” jack is the audio input of the Bad Stone. The input impedance is
95kΩ.
AMP Jack – This ¼” jack is the audio output of the Bad Stone. The output impedance is
4.7kΩ.
9V Power Jack – The Bad Stone operates with a standard 9V battery or an optional 9VDC
AC Adaptor capable of delivering at least 25mA to the 9V power jack, such as the
EHX9.6DC-200. The AC Adapter must have a center negative plug. The battery may be
left in or taken out when using an AC Adaptor. The Bad Stone has a current draw of 18mA
at 9VDC.
CONTROLS

CHANGING THE BATTERY
To change the 9V battery, you must remove the 4 screws on the bottom of the Bad Stone.
Once the screws are removed, you can take the bottom plate off and change the battery.
Please do not touch the circuit board while the bottom plate is off for risk of damaging a
component.
WARRANTY INFORMATION
Please register online at http://www.ehx.com/product-registration or complete and return
the enclosed warranty card within 10 days of purchase. Electro-Harmonix will repair or
replace, at its discretion, a product that fails to operate due to defects in materials or
workmanship for a period of one year from date of purchase. This applies only to original
purchasers who have bought their product from an authorized Electro-Harmonix retailer.
Repaired or replaced units will then be warranted for the unexpired portion of the original
warranty term. If you should need to return your unit for service within the warranty
period, please contact EHX Customer Service at 718-937-8300 or info@ehx.com for a
Return Authorization Number. Along with your pedal, please include a brief description of
the problem as well as your name, address, telephone number, copy of your receipt, and a
check or money order.
United States - $12 Ship to:
Canada - $15 Electro-Harmonix
Europe and outside countries - $25 C/O New Sensor Corporation
55-01 2nd Street
Long Island City, NY, 11101
Please make checks/money orders payable to New Sensor Corporation.
To hear demos on all EHX pedals visit us on the web at www.ehx.com
Email us at info@ehx.com.
Attn: Service Department