Electro-Harmonix Q-Tron Plus Instruction Manual

Q-TRON PLUS

Envelope Controlled Filter with External Loop and

“Response” Control

Congratulations on your purchase of the Q-Tron Plus enhanced envelope controlled
filter. It is a very powerful tool for musical expression. Please take a few minutes to
familiarize yourself with the Q-Tron Plus features and controls.

Envelope controlled filters are unique sound modifiers since the intensity of the effect
is controlled by the user’s player dynamics. The volume (also known as the envelope)
of the musician’s notes are used to control a swept filter. As the volume of your notes
changes, so does the peak frequency of the filter.

-CONTROLS-

Gain Control (0-11)– In normal mode, the gain control acts as a filter sensitivity
control and has no effect on the unit’s output volume. In Boost mode, the Gain
control functions as both a volume control and the filter sensitivity control.

Boost Switch (Normal/Boost) – Normal mode passes input signal through the filter at
its original level. Boost mode increases the signal gain to the filter according to the
Gain control setting.

Response Switch (Fast/Slow) – Changes the sweep response between two optimized
settings. “Slow” response creates a smooth vowel-like response. “Fast” response
produces a snappy response identical to the original Q-Tron.

Drive Switch (Up/Down) – Selects the direction of the filter sweep.

Range Switch (Hi/Lo) – Emphasizes vowel-like sounds in low position and overtones
in high position.

Peak Control (0-11) – Determines the resonance peak or Q of the filter. Turning the
control clockwise increases the Q and creates a more dramatic effect.

Mode Switch (LP, BP, HP, Mix) – Determines what frequency range the filter will pass.
Emphasize bass with Low Pass, midrange in Band Pass and treble with the High Pass.
Mix mode combines BP with the dry instrument signal.

Bypass Switch (In/Out) - Toggles between effect mode and True Bypass. When the
Q-Tron Plus is in bypass, the effect loop is also bypassed.

Your Playing Dynamics-The Q-tron Plus’ effect is controlled by the user’s player
dynamics. Strong attack will yield a more dramatic effect, while a softer playing yields
more subtle ones.

-EFFECTS-

The Effects loop allows you to place an additional musical effect between the Q-Tron
Plus’ preamp and filter sections without any alteration of the envelope drive. This
allows the full dynamic response to your playing while greatly increasing the sound
possibilities: Fuzz, soft distortion, echo and chorus, octave divider etc.

When you use an external effect in the Effect’s Loop, the footswitch on the external
effect can control whether the signal is “in” or ”out”. The Q-Tron Plus footswitch will
always switch between the Q-Tron process and the original input signal regardless of
the state of the external effect.

-JACKS-

Input Jack- Musical instrument signal input. The input impedance presented at this
jack is 300 kΩ.

Effects Out Jack- Output to amplifier. The output impedance is 250 Ω.

FX Loop Send Jack- Musical instrument signal output to external musical effect. The
output impedance is 250 Ω.

FX Loop Return Jack- From External musical effect output to Q-Tron Plus filter
process. The input impedance presented at this jack is 300 kΩ.

-AC ADAPTOR-

Your Q-Tron Plus comes equipped with a 24 volt DC (inner positive) / 100mA external
power adapter. Use only the power adapter that is supplied! Using the wrong adapter
can cause serious bodily injury and may damage your unit. This will void the
warranty.

-OPERATION-

Set all controls to minimum. Connect your instrument to the input jack and your
amplifier to the effect out jack. Optionally connect an external effect to the Effects
Loop. The unit’s power LED should be lit. Set the Q-Tron Plus’ controls to the
following:

Drive Switch: UP
Response Switch: Slow
Range Switch: Low
Mode Switch: BP
Peak Control: Maximum
Boost Control: Normal
Gain Control: Variable*

* Vary the gain control until the Overload Indicator LED lights on the loudest notes
that you play. If no effect is noticeable, depress the Bypass switch to engage the
effect. With this setting the user should be able to approximate the sound of an
automatic wah-wah pedal.

Experiment with these settings to see how the Q-Tron Plus reacts to playing
dynamics. Adjusting the Gain and Peak controls will vary the amount and intensity of
the effect. For tonal variations adjust the Range, Mode and Drive controls.

To attain an effect similar to an original Mu-Tron III, set the Q-Tron Plus’ controls to
the following:

Drive Switch: Down
Response Switch: Fast
Range Switch: Low
Mode Switch: BP
Peak Control: Mid Point
Boost Control: Boost
Gain Control: Variable*

* Vary the gain control until the Overload Indicator LED lights on the loudest notes
that you play. Increasing gain will saturate the Filter, yielding the famous “chewy”
Mu-Tron like sounds. Adjusting the peak control will vary the intensity of the effect.
For tonal variations, adjust the Range, Mode and Drive controls.

-OPTIONS FOR USE-

The Q-Tron Plus can be used with a wide variety of electronic instruments. Here are
some setting tips for use with different instrument types.

Range Control- Lo range is best for rhythm guitar and bass. Hi range is best for lead
guitar, brass and winds. Both ranges work well for keyboards.

Mix Mode: Works especially well with bass guitar (may require higher peak settings).

Drive Switch: Down drive works well with Bass guitar. Up Drive is best with guitar
and keyboards.

The Q-Tron Plus can also be used in conjunction with other effects pedals. Here are
some interesting combinations.

Q-Tron Plus and Big Muff (or tube amp distortion)- Place the distortion device after
the Q-tron Plus in the signal chain, or effects loop. The use of distortion will
dramatically increase the intensity of the Q-Tron Plus’ effect. You can also place the
distortion before the Q-Tron Plus but this combination tends to flatten the dynamic
response range of the effect.

Q-Tron Plus into a Q-Tron Plus - (or another Q-Tron in effects loop) - Try this with
one unit in the up drive position and the other in the down drive position.

Q-Tron Plus and Octave Multiplexer- Place the octave divider before the Q-Tron Plus
in the signal chain or in the effects loop. Use an octave divider, which maintains the
natural envelope of the signal. This combination will yield sounds similar to an analog
synthesizer.

Q-Tron Plus and compressor, flanger, reverb etc in effects loop- create interesting
tonal colors while retaining full control of the Q-Tron Plus’ filter sweep.

Try experimenting with other effects and effect placement (before Q-Tron Plus, after
it or in the effects loop) to achieve your own unique sound. When used properly the
Q-tron Plus will provide a lifetime of playing pleasure.