Electro-Harmonix Bass Mono Synth User manual

BASS MONO SYNTH
Congratulations on your purchase of the Electro-Harmonix Bass Mono Synth. The
Bass Mono Synth allows you to transform your bass guitar into one of eleven
different synthesizers, from vintage synth emulations, to thick, stacked voices, to
deep pulsing sounds for an array of sonic landscapes and textures. The Bass
Mono Synth was designed to work on your bass guitar without any modifications
or special pickups. Plug your bass right in and immediately join the ranks of
legendary synthesizer musicians.
WARNING: Your Bass Mono Synth comes equipped with an Electro-Harmonix 9.6DC-
200BI power supply (same as used by Boss®& Ibanez®: 9.6 Volts DC 200mA). The Bass
Mono Synth requires 125mA at 9VDC with a center negative plug. Using the wrong
adapter or a plug with the wrong polarity may damage your Bass Mono Synth and void
the warranty.
GETTING STARTED
Connect the supplied power adapter to the 9V power jack. Plug your bass into the
INPUT jack. Connect your amp or other effects pedals to the SYNTH OUTPUT jack.
Set the DRY knob to the minimum (fully counterclockwise) and set the other top
row knobs to 12 o’clock. Select a TYPE and step on the BYPASS footswitch to turn
on the LED. Play your bass and adjust controls to your liking.
ONE NOTE AT A TIME
The Bass Mono Synth is a multi-oscillator monophonic instrument. It synthesizes
one note at a time per oscillator. The oscillators have been pre-tuned for each
synth type, only the sound SPECTRE allows for user control over an oscillator.
Additionally it can handle only one note from your bass at a time. It does not work
properly when chords or two note intervals are played. The Bass Mono Synth
behaves unpredictably and erratically when it receives more than one note at the
INPUT jack.
SYNTH TYPE DESCRIPTIONS
1. LASER –deep, pulsating synth.
CTRL: this knob adjusts the attack and decay times of the filter envelope.
As CTRL is turned clockwise both the attack and decay times slow down.
EXP: the expression pedal controls the cutoff frequency of the filter which
also sets the jump-off frequency for the envelope sweep. As the pedal
travels from heel to toe the filter frequency goes from bass to treble.
2. X-FADE –full, string-like synth.
CTRL: sets the decay time of the filter envelope.

EXP: controls the cutoff frequency of the filter and the base of the filter
envelope sweep.
3. ACID –fast decaying synth reminiscent of the TB-303.
CTRL: adjusts both filter resonance and sweep depth of the filter
envelope. As CTRL is turned clockwise, both resonance and filter
envelope frequency range increase.
EXP: triggered by picking attack, the expression pedal controls the filter
envelope’s decay time. Decay time increases as the pedal is swept from
heel to toe.
4. COSMIC –bright and aggressive synth with subtle pitch modulation.
CTRL: sets the decay time of the filter envelope.
EXP: controls pitch modulation depth.
5. SUB –round sub-octave synth for adding low end.
CTRL: controls the volume of the sub-octave oscillator.
EXP: controls the cutoff frequency of the filter.
6. GROWL –percussive, punchy synth.
CTRL: sets the decay time of the filter envelope.
EXP: controls the filter envelope’s sweep depth or frequency range.
7. WUB –pulsating synth with a modulating filter.
CTRL: sets the speed of modulation.
EXP: controls the filter’s center frequency.
8. UNISON –Like stacking the voices on a polyphonic synth, UNISON has a
huge, full sound.
CTRL: sets the decay time of the filter envelope.
EXP: controls the cutoff frequency of the filter and the base of the filter
envelope sweep.
9. TWIN –A throaty synth sound.
CTRL: adjusts the attack and decay times of the filter envelope.
EXP: controls the filter envelope’s sweep depth or frequency range.
10. SPECTRE –full synth with an added adjustable pitched note.
CTRL: controls the filter’s cutoff frequency.
EXP: controls the pitch of the added note in half-step increments. The
pitch ranges from -1 octave—at the heel—to + 4 octaves—at the toe.
11. OBLIVION –big, lush, warm synth tone with a warbling modulation effect.
CTRL: controls the rate of modulation.
EXP: controls the resonance of the filter.

CONTROLS AND I/O JACKS
DRY VOL Knob
The DRY VOL knob controls the volume of the untreated bass signal present at the
SYNTH OUTPUT jack.
SYNTH VOL Knob
The SYNTH VOL knob controls the overall volume of the synthesizer sound at the
SYNTH OUTPUT jack.
SENS Knob
The SENS knob adjusts the gain of the input signal before the signal hits the
Bass Mono Synth’s trigger block. The trigger block generates synth notes that
match the pitch of the notes you play on your bass and starts all envelope
sweeps. It will only trigger new notes when the input signal exceeds its
threshold. The SENS knob (short for sensitivity) allows you to change the signal’s
amplitude to have finer control over the notes that trigger threshold. Lower
settings of SENS will require louder notes to trigger the synthesizer while higher
settings of SENS might trigger new synth notes with every note you play. As a
tool, to help set the SENS knob, the LED lights orange when the input signal to
the synth engine exceeds -4.6dB. Setting the SENS knob so this LED lights
orange on your loudest notes is a good place to start. Please note: the LED does
not indicate when the input signal has triggered a new note, it lights only to
indicate the loudness of the input. If many of your notes do not trigger the
synth, then turn up SENS. If you hear many false triggers or retriggers without
playing a new note then turn down SENS.
CTRL Knob
This knob can be used to control a specific parameter for each synth type. See
the TYPE DESCRIPTIONS on pages 1 and 2 to learn more.
INPUT Jack
Plug your bass or the output of another effects pedal into this ¼” jack. See Tips 1
& 2 on Page 7 for more on connecting your Bass Mono Synth.
DRY OUTPUT Jack
The DRY OUTPUT jack is hardwired to produce a buffered version of the signal
present at the INPUT jack. In either EFFECT or BYPASS mode, the dry signal is
always present at the DRY OUTPUT jack. The DRY knob does not change the
volume of the signal at the DRY output jack.
SYNTH OUTPUT Jack
The SYNTH OUTPUT jack outputs the mix set by the DRY and SYNTH volume
controls. In BYPASS mode, SYNTH OUTPUT outputs the buffered bypass signal.
EXP Jack
The EXP jack accepts a TRS cable from a standard passive expression pedal.
Each synth type has a specific parameter controlled by the expression pedal, as
explained in the TYPE DESCRIPTIONS section.

When saving a preset, the expression pedal position is saved along with the
knobs. If the expression pedal is not present or has not been moved since
recalling the preset, the Bass Mono Synth will load the saved expression pedal
setting. This allows you to tweak the parameter(s) controlled by the expression
pedal to later recall with your presets.
The expression pedal’s plug must be wired with the Sleeve connected to the heel
position (usually GND), Ring connected to the toe position and the Tip connected
to the wiper. The nominal expression pedal impedance is 10kΩ though most
other values will work fine. Please do not go below 6kΩ on your expression
pedal’s potentiometer impedance. Some suggested Expression Pedals: EHX
Expression Pedal, M-Audio® EX-P, Moog® EP-2 and EP-3, Roland® EV-5 and
Boss® FV-500L. Additionally, the EXP IN jack can be connected to a CV source
using a TS plug; the acceptable control voltage range is 0V to 5V.
BYPASS Footswitch
Press the BYPASS footswitch to toggle the SYNTH OUTPUT jack between buffered
bypass and effect modes. The status LED lights when you are in effect mode.
PRESET Footswitch
Use this footswitch to toggle between Preset and live What You See Is What You
Get (WYSIWYG) modes. The PRESET footswitch is also used to save a preset to
the current synth type set by the TYPE knob. See the PRESETS section for more
information on saving and recalling presets.
Status LED
The Status LED lights while the Bass Mono Synth effect is engaged. The Status
LED is off when the unit is in buffered bypass. The LED lights green for
WYSIWYG mode and lights red when preset mode is selected. The LED lights
orange when the SENS threshold has been exceeded.
PRESETS
When the LED on the Bass Mono Synth is green, you are in WYSIWYG mode,
meaning that the current knob and expression pedal settings represent the
sound that is produced. You can also save and recall one preset for each of the
eleven synth types. Each of the four knobs in the top row will be saved along
with the setting of the expression pedal if one is attached at the time of saving
the preset. When a preset is active, the LED is red.
RECALLING A PRESET
1. Assuming the Status LED is green at the moment, turn the TYPE knob
to the synth type that you want to recall. If the Status LED is currently
red skip to step 3.
2. Press and release the PRESET footswitch. The preset for the current
synth type will be recalled and the Status LED will light red.

3. At this time you may turn the TYPE knob to load the preset for each
synth type.
4. Press and release the PRESET footswitch to return to WYSIWYG mode.
SAVING A PRESET
1. A preset may be saved while either in WYSIWYG or Preset mode.
2. Press and hold the PRESET footswitch. After holding for about 3
seconds you will see the LED blink red at a fast rate.
3. Once the LED blinks red you may release the PRESET footswitch, the
preset is now saved.
4. If an expression pedal is attached we recommend you don’t move it
while saving a preset.
EDITING A PRESET
1. After recalling a preset, the LED lights red and does not blink.
2. If you move any of the four knobs in the top row of knobs, the LED
blinks red—at a slow pace—to indicate that a preset is loaded but has
been changed in some way.
3. The LED does not blink if you move the expression pedal after loading a
preset.
4. If you press and release the PRESET footswitch while the LED is
blinking red, it will reload the preset from memory. After reloading the
LED will light solid red again.
5. If you press and hold the PRESET footswitch while the LED is blinking
red, your newly edit preset will be saved to memory. Press and hold the
PRESET footswitch until you see the LED blink quickly.
EXITING PRESET MODE
To exit Preset mode and return to WYSIWYG mode, simply press and release the
PRESET footswitch. The LED will turn green. If the preset had been edited and
you see the LED blinking red, press and release the PRESET footswitch twice to
return to WYSIWG mode.
EXPRESSION PEDAL PARAMETERS AND PRESETS
If an expression pedal is connected to the Bass Mono Synth at the time you save
a preset, the current state of the parameter controlled by the expression pedal
will be saved within the preset. Moving the expression pedal while in a preset
will not result in the LED blinking slowly (indicating an edited preset). If you
later recall a preset without an expression pedal, the parameter controlled by the
expression pedal will be recalled with the expression value at the time of saving.
Upon moving back to WYSIWYG mode, that parameter will go back its default
setting.

FACTORY RESET
To perform a factory reset and restore all default presets do the following:
1. Unplug the power from the Bass Mono Synth.
2. Press and hold the BYPASS footswitch as you apply power.
3. Continue to hold down the BYPASS footswitch until you see the LED
toggle between green and red. Normally it will take four seconds for the
LED to begin toggling.
4. Once the LED starts toggling between green and red you can release
the BYPASS footswitch.
5. About four to five seconds later the LED will light green and then shut
off. The factory reset is complete.
NOTES AND SPECIFICATIONS
Buffered bypass
Input impedance: 2.2M
Output impedance (for both output jacks): 680
Current draw: 125mA
TIPS ON GETTING OPTIMUM PERFORMANCE FROM THE BASS
MONO SYNTH
1. The Bass Mono Synth is generally best used as the first pedal in an effects
chain. Place modulation, delay, and reverb effects after the Bass Mono
Synth. The unit will not perform well if placed in the effects loop of a guitar
amp.
2. Avoid placing a distortion or overdrive in front of the Bass Mono Synth,
which could muddy up the input signal and cause the tracking to be
unstable. If you want to add overdrive or distortion, place it after the Bass
Mono Synth.
3. Make sure to play only one note at a time. The Bass Mono Synth acts
unpredictably and erratically when it receives two or more notes at once.

FCC COMPLIANCE
Note: This equipment has been tested and found to comply with the limits for a Class B
digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation. This
equipment generates, uses and can radiate radio frequency energy and, if not installed and
used in accordance with the instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and on, the user is
encouraged to try to correct the interference by one or more of the following measures:
 Reorient or relocate the receiving antenna.
 Increase the separation between the equipment and receiver.
 Connect the equipment into an outlet on a circuit different from that to which the
receiver is connected.
 Consult the dealer or an experienced radio/TV technician for help.
Modifications not expressly approved by the manufacturer could void the user's authority to
operate the equipment under FCC rules.

- 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
the appropriate office listed below. Customers outside the regions listed below, please
contact EHX Customer Service for information on warranty repairs at [email protected] or +1-
718-937-8300. USA and Canadian customers: please obtain a Return Authorization
Number (RA#) from EHX Customer Service before returning your product. Include  with
your returned unit  a written description of the problem as well as your name, address,
telephone number, e-mail address, RA#, and a copy of your receipt clearly showing the
purchase date.
United States & Canada
EHX CUSTOMER SERVICE
ELECTRO-HARMONIX
c/o NEW SENSOR CORP.
55-01 2ND STREET
LONG ISLAND CITY, NY 11101
Tel: [phone]
Email: [email protected]
Europe
JOHN WILLIAMS
ELECTRO-HARMONIX UK
13 CWMDONKIN TERRACE
SWANSEA SA2 0RQ
UNITED KINGDOM
Tel: [phone]
Email: [e-mail]
To hear demos on all EHX pedals visit us on the web at www.ehx.com
Email us at inf[email protected]