MU-FX MU-FX PHASOR 2X User manual

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MU-FX PHASOR 2X
SPECIFICATIONS AND OPERATION
MUSICIAN’S MANUAL

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The Mu-FX PHASOR 2X is the enhanced reissue of the vintage
classic Musitronics Mu-Tron® Phasor II
The PHASOR 2X is a multi-mode phase shifter with enhanced audio and control features
which provide simple, intuitive and performance-oriented control versatility. The
PHASOR 2X retains the vintage classic sound of the Phasor II, which offered distortion-
free audio processing and feedback-controlled effect emphasis for the cleanest possible
sound.
The Mu-FX Phasor 2X provides 4 and 6 stage OPTICAL phasing –for the best possible
dynamic range and signal-to-noise ratio - without the distortion inherent in FET and
transconductance-amp phasors. The EMPHASIS of the phasing effect is produced with
FEEDBACK around the electro-optical resistive phase circuitry without creating
distortion of the signal.
To preserve the best possible dynamic range and signal-to-noise ratio, the Phasor 2X is
powered from external 12Volt AC power and internal LINEAR voltage regulators. This
eliminates the signal noise, distortion and radio frequency interference caused by
“switching regulator” power supplies.
The Phasor 2X also uses TRUE-GROUND dual power supply rails and other specialized
components to further minimize distortion and sensitivity to external RF interference.
The phase sweep is optimized for each unit to give the smoothest sounding sweep. The 4
and 6 stage phasing, controlled by a foot switch, is also optimized for best sweep range
and characteristic for each type of phasing.
Simple, intuitive, and performance oriented!
The controls are very simple: RATE, DEPTH and FEEDBACK for each of the 4 and 6
stage modes. This allows easy and independent adjustment without having to compensate
for the different characteristics of 4 and 6 stage phasing modes.
The 4 and 6 modes are instantly accessible with the PHASE MODE foot switch.
Pedal control switches for each (4 and 6) mode allow you to set dramatically different
kinds of expression pedal (or external CV) effects.

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FEATURES AND SPECIFICATIONS
•4 and 6-stage phasing modes (foot-switch selectable to main output)
•Smooth and consistent phase sweep by LFO, expression pedal or control voltage
•Stereo output for 4 and 6 stage modes (“secret sauce” phasing to second (or
stereo) output)
•Electro-optical phasing with superior dynamic range, no distortion and low
noise level
•Retro “Mini-MU” housing with original “Mu-Tron®” Phasor II color scheme
•Powered by 12V AC for optimal dynamic range and signal-to-noise ratio
LFO starts precisely from the LOW END OF SWEEP when effect is engaged. So,
you can count on a consistent, predictable LFO sweep, especially good for slow sweep
rates!
Footswitch control and dual-color LED indicator for 4 or 6-stage phasing and control set
BLUE is for 6-Stage Phase (and top BLUE knob pointers)
GREEN is for 4-Stage Phase (and top GREEN knob pointers)
EFFECT/BYPASS Footswitch and 3-color LED indicator
RED for BYPASS
BLUE-to-GREEN for PHASE RATE or SWEEP
RED/BLUE or RED/GREEN for pedal control indicator
Expression Pedal or CV control of RATE or SWEEP for both 4 and 6-stage phaser banks
All audio switching by “silent” footswitches and electromechanical relays
Internal Switch setting for TRUE or ACTIVE bypass: (MAIN and STEREO outputs)

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PANEL CONTROLS: TOP PANEL
6-STAGE MODE CONTROLS
RATE 6: Exponential LFO (from 10 second period to 20 Hz)
DEPTH 6: LINEAR Sweep control from zero sweep to full-scale (optimized for 6-stages)
FEEDBACK 6: Zero to max positive feedback around phase stages
PED/CV SWITCH 6: RATE –OFF –SWEEP
4-STAGE MODE CONTROLS
RATE 4: Exponential LFO (from 10 second period to 20 Hz)
DEPTH 4: LINEAR Sweep control from zero sweep to full-scale (optimized for 4-stages)
FEEDBACK 4: Zero to max positive feedback around phase stages
PED/CV SWITCH 4: RATE –OFF –SWEEP
PANEL CONTROL DETAILS
RATE, DEPTH, FEEDBACK controls for each of 6 and 4 stage phasing modes,
selectable by 4-6 footswitch
RATE: Continuous control of LFO
0.05Hz to 20 Hz for top control set (6-stage phasing)
0.1 to 10 Hz for bottom control set (4-stage phasing)
- LFO always starts from LOW END OF SWEEP when effect is engaged after
bypass is engaged (to provide consistency of effect)
- LFO LED indication of RATE is provided on BYPASS LED - whether or not
the unit is in bypass mode
- LFO LED also indicates that a pedal or CV control is connected to the PED/CV
JACK (RED added to BLUE-to-GREEN
SWEEP / DEPTH: Full Sweep range is OPTIMIZED for both 4 and 6-stage phasing
- In LFO mode, SWEEP RATE is controlled by ultra-linear LFO sweep generator
according to DEPTH control
- In PEDAL control mode, LFO is disabled and SWEEP is controlled by pedal,
over its full excursion
FEEDBACK: provides positive regenerative feedback across phase stages for effect
emphasis -- without distortion of audio signal -- for each of 4 and 6 modes
PEDAL/ CV CONTROL SWITCHES: Independent for each of the 4 and 6-stage phase
modes, a 3-position toggle switch controls the pedal function when an XP-2 control pedal
is plugged into the pedal jack
Even if you don’t have an expression pedal or external Control Voltage connected to
the pedal jack, these switches DO have a useful function:
--When the control pedal switches are in the OFF (center) position, the PANEL
CONTROLS (Rate and Depth) entirely determine the phase shift settings.

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--When either switch is set to RATE, the phase rate acts as if a pedal were set to
its mid-sweep position, and offsets the LFO rate accordingly
--When ether switch is set to DEPTH, the LFO is disabled! And the DEPTH
control sets the sweep to a non-swept Multi-Pole Filter function.
FOOT SWITCH CONTROLS DETAILS
BYPASS FOOTSWITCH: Silent footswitch operates mechanical relay bypass function
PHASE STAGE FOOTSWITCH: Silent footswitch operates solid-state audio switch
between 4 and 6 stage operation
JACKS: BACK PANEL
INPUT Jack: 1Megohm input impedance (capacitively coupled) in EFFECT or ACTIVE
BYPASS mode;
- Greater than 11Meg DC to system ground in TRUE bypass mode for ESD
protection.
- Both modes are ESD (electrostatic discharge transient) protected by ferrite bead
at input and both output jacks.
OUTPUT 1 Jack: 150 ohm output impedance (capacitively coupled) in EFFECT or
Active Bypass mode;
- DC coupled to INPUT jack in TRUE bypass mode. Greater than 11Meg resistive
coupled system ground in TRUE bypass mode.
- Both modes ESD protected by ferrite bead at input and output jacks.
OUTPUT 2 Jack: 1Megohm input impedance capacitively coupled in EFFECT or Active
Bypass mode;
- DC coupled to INPUT jack in TRUE bypass mode. Greater than 11Meg to
system ground in TRUE bypass mode.
- Both modes ESD protected by ferrite bead
EXP PEDAL Jack: For use with either Mu-FX/Mission XP-2 pedal or external Control
Voltage (0-5 volts low-impedance drive for full range of RATE or SWEEP).
Ring: 5V short-circuit protected voltage to XP-2 pedal, 10 milliamps output to XP-2
External CV: 0 to 5V DC for full-scale excursion of LFO RATE or Full-
range SWEEP
Should ONLY be connected with T-R-S plug, using TIP (CV) and SLEEVE
(Ground) and with RING un-connected.

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CV input DC Resistance: 1 Meg ESD protected, biased to 2.5V
TIP - input control voltage from XP2 or External CV input
SLEEVE - Control signal ground
Do not use RING to power an external CV device!
POWER SUPPLY JACK: 12V AC ONLY at 50-60 Hz, 15V AC Maximum, 200
milliamp max current draw.
Use with any other voltage or any DC voltage supply may damage the product and void
the warranty!
Power supply is protected against ESD transients and internal short circuit by ferrite bead
and self-resetting fuse.
INTERNAL FUNCTIONS (Use extreme care if you open the housing!):
INTERNAL BYPASS MODE SWITCH:TRUE bypass or ACTIVE bypass select
on inside circuit board.
THE INTERNAL SWITCH IS FACTORY PRE-SET TO TRUE-BYPASS
MODE.
NOTE: NONE OF THE INTERNAL TRIM-POTS ON THE PC BOARD ARE
USER-ADJUSTABLE!!! DO NOT ADJUST!!!!
THIS WOULD VOID THE FACTORY WARRANTY

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WARRANTY: 1Year Parts and Labor for defects in product resulting in product
failure or faulty performance. Tampering with product or accidental breakage will void
the warranty.