Electro-Harmonix Deluxe Big Muff Pi User Manual
- June 6, 2024
- electro-harmonix
Table of Contents
Deluxe Big Muff Pi
Congratulations! You have just purchased the ultimate harmonic distortion- sustain device developed to date for the electric guitar player: the Deluxe Big Muff Pi! We started with our beloved NYC Big Muff Pi and carefully added select new features to create a versatile distortion that is extremely musical sounding. Please review this manual to learn the unique potential of the Deluxe Big Muff Pi.
Features Include:
- Big Muff Knob Layout – familiar Sustain, Tone and Volume controls
- MIDS EQ – fully parametric MIDS EQ includes variable frequency sweep, boost or cut level control, and switchable Q or bandwidth amount
- Footswitch for MIDS EQ – turn on the MIDS EQ circuit with the stomp of your foot
- Gate – remove unwanted hum
- Attack – preserves pick attack with an enhanced version of your dry signal
- Bass Boost – switchable bass boost
- Expression Pedal Input – sweep the frequency of the MIDS EQ with your foot
- True Bypass
The Deluxe Big Muff Pi feature set is a culmination of ideas Mike Matthews has always wanted to see in a Big Muff plus suggestions from many friends of Electro-Harmonix. The MIDS EQ allows tonal shaping of the Big Muff distortion like never seen before, the GATE function lends itself to playing the Big Muff in new ways providing blasts of fuzz when you play and silence when you don’t, the ATTACK control adds definition to chords and riffs without getting in the way of the Big Muff’s original tone, and BASS BOOST brings back some low end when TONE is turned up to its treble settings.
CONTROLS
VOLUME Knob – Works as a master volume control for the entire pedal.
TONE Knob – Provides a range of sounds from high treble to deep bass. As
you turn the TONE knob clockwise, treble increases and bass decreases.
SUSTAIN Knob – As in the original Big Muff Pi, adjusts the amount of
sustain and distortion.
BASS BOOST/NORMAL Switch – When set to NORMAL, the Big Muff circuit is
identical to our NYC Big Muff that we currently manufacture. Flip the switch
up to BASS BOOST and the volume level of bass frequencies through the Big Muff
circuit increases. Although the BASS BOOST function can be subtle it is most
useful when the TONE is set above the center, 12 o’clock position.
ATTACK Knob – Is a volume control for the Attack effect. As you turn the
ATTACK knob clockwise the Attack volume increases. Turn ATTACK all the way
down (fully counter-clockwise) to turn to Attack off.
The Attack signal path runs in parallel to the Big Muff’s circuit. The function of the Attack circuit is to enhance the sound of your picking by applying 2 carefully chosen bandpass filters to the input signal followed by a volume expander that ensures your pick attack is louder than the sustained portion of the note. The Attack signal is not clean; it is usually very gritty but not nearly as distorted as the Big Muff circuit.
GATE Knob – Turning GATE clockwise raises the Gate threshold requiring greater input amplitude to open the noise gate, allowing your notes to be heard and your instrument to pass through. Turn the GATE knob down all the way, to fully counter-clockwise, to disable the noise gate.
MIDS LEVEL Knob – When MIDS is engaged (LED near MIDS Footswitch is lit) the MIDS LEVEL knob either boosts or cuts up to +/- 10dB, at the frequency set by the FREQ knob located below it. Turn MIDS LEVEL clockwise from its center 12 o’clock position to boost the center frequency. To cut, turn MIDS LEVEL counter-clockwise from the 12 o’clock position. This knob has a notch near the 12 o’clock position to help identify the center of the knob’s travel. In the center position, MIDS EQ is flat; it does not boost or cut. The MIDS LEVEL knob has no function when MIDS is bypassed (LED near MIDS Footswitch is off).
MIDS FREQ Knob – Sets the center frequency of the MIDS EQ circuit ranging from 310Hz to 5.0kHz. To hear the range of the MIDS FREQ knob, turn the MIDS LEVEL knob up past 3 o’clock, make sure MIDS is enabled (LED near MIDS Footswitch is lit), then play your instrument while turning the MIDS FREQ knob. This knob has no function if either the MIDS section is bypassed (LED near MIDS Footswitch is off) or the MIDS LEVEL knob is set to its center position.
The MIDS FREQ knob can be controlled by an external expression pedal or control voltage (CV). Connect the external device to the EXP jack on the input side of the Deluxe Big Muff. The position of the MIDS FREQ knob sets the toe position of the expression pedal or maximum frequency for CV. The heel position of the expression pedal equals the MIDS FREQ knob’s fully counter- clockwise position. Please see EXP Input below for more on the expression pedal.
MIDS Q Switch (HIGH/LOW) – The Q switch sets the resonance or bandwidth of the MIDS EQ. What this means is in LOW mode the EQ sounds broader or rounder and affects a larger range of frequencies; in HIGH mode the EQ sounds sharper or peakier and affects a narrow range of frequencies.
MIDS FOOTSWITCH / LED – Engages or bypasses the MIDS EQ section. When the white status LED is lit, the MIDS EQ circuit is active and the MIDS LEVEL and FREQ knobs can be used to produce a multitude of different tones.
BYPASS FOOTSWITCH / LED – Toggles between effect mode and true bypass. When the red status LED is lit, the effect is active. When the LED is off, the Deluxe Big Muff Pi is in True Bypass mode.
I/O AND POWER CONNECTIONS
INPUT – Plug your instrument into here. The input impedance presented at
this jack is approximately 130k.
OUTPUT – This is the output of the Deluxe Big Muff Pi. Connect it to the
input of your amp or another effects pedal. The output impedance at the OUTPUT
jack is 300 ohms.
EXP Input – Connect an expression pedal with a TRS plug to this jack to
sweep the MIDS center frequency with your foot or another extremity.
Additionally, the EXP IN jack can be connected to a Control Voltage (CV)
source using a TS plug; the acceptable range for the control voltage is 0V to
5V. Some suggested Expression Pedals: EHX Expression Pedal, M-Audio® EX-P,
Moog® EP-2, Roland® EV-5 or Boss® FV-500L. The polarity of the expression
pedal’s plug must connect the Sleeve to the heel position, Ring connected to
the toe position, and Tip connected to the wiper. The nominal expression pedal
impedance is 10k but it can accept impedances ranging from 6k to 100k. Please
note: if the MIDS EQ section is bypassed, the expression pedal is disabled.
9V POWER – The Deluxe Big Muff can run off of a 9V battery or you can use a 9VDC AC Adapter capable of delivering at least 50mA. The optional 9V power supply from Electro-Harmonix is the 9.6DC200BI (same as used by BossTM & IbanezTM) and delivers up to 200mA at 9.6 Volts DC. The actual current draw of the Deluxe Big Muff is 22mA at 9VDC. The AC Adapter must have a barrel connector with a center-negative plug. The Deluxe Big Muff accepts most BOSS® style AC Adapters. Please do not exceed 12VDC at the power jack. The battery may be left in or taken out when using an AC Adapter.
OPERATION AND WARNINGS
CHANGING THE BATTERY
To change the 9-Volt battery, you must remove the 4 screws on the bottom of
the Deluxe Big Muff Pi. Once the screws are removed, you can take off the
bottom plate and change the battery. Please do not touch the circuit board
while the bottom plate is off or you risk damaging a component.
SHIELDING
To achieve its long sustain, the Deluxe Big Muff Pi has a very high maximum
gain. This requires that pickups and cables be well shielded and properly
grounded to avoid excessive hum when high sustain knob settings are used.
INTERNAL TRIM POTS
The Deluxe Big Muff Pi’s MIDS EQ section has three trim pots for adjusting the
following: 1) High Q bandwidth, 2) High Q Output Volume and 3) overall MIDS EQ
Output Volume. We set these trim pots at the factory so that 1) HIGH Q mode is
very resonant but does not self-oscillate 2) HIGH Q mode is just a bit louder
than LOW Q mode and 3) when engaged, MIDS EQ creates a slight volume boost
over MIDS EQ bypassed for most settings of MIDS knobs.
We realize our settings may not be perfect for everyone. If you would like to make adjustments to the trim pots, remove the 4 screws on the bottom of the unit and remove the bottom plate. Place the pedal knobside-down with the power jack facing away from you. In the upper left area of the printed circuit board, you will see three small trim pots.
Before you start: we recommend you photograph or sketch the position of
each trim pot as it came to you from the factory in case you want to go back
to those settings. The factory trim pot settings vary considerably from unit
to unit.
When adjusting the trim pots use a small flat head or slotted screwdriver with
a width of 2mm. Please do not touch any other parts of the circuit board while
the bottom plate is off or you risk damaging a component.
The signal path through the trim pots goes in this order:
HI Q AMT (TRIM1) HI Q VOL (TRIM2) MID EQ OUT VOL (TRIM3)
Change HI Q’s bandwidth by adjusting HI Q AMT. The volume level of HI Q mode
also changes: increasing HI Q AMT increases HIGH Q’s volume; decreasing HI Q
AMT decreases HIGH Q’s volume. Therefore if you adjust HI Q AMT you may also
need to adjust the HI Q VOL trim pot.
If you want to change the volume of LOW Q mode: 1) adjust the MID EQ OUT VOL
trim appropriately until you are happy with LOW Q’s volume, 2) compare HIGH
Q’s volume to LOW Q’s volume and adjust the HI Q VOL trim if necessary.
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 the 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 info@ehx.com 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, and 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.
47-50 33rd STREET LONG ISLAND CITY, NY 11101
Tel: 718-937-8300
Email: info@ehx.com
Europe
JOHN WILLIAMS
ELECTRO-HARMONIX UK
13 CWMDONKIN TERRACE
SWANSEA SA2 0RQ
UNITED KINGDOM
Tel: +44 179 247 3258
Email:
electroharmonixuk@virginmedia.com
This warranty gives a purchaser specific legal rights. A purchaser may have
even greater rights depending upon the laws of the jurisdiction within which
the product was purchased.
To hear demos on all EHX pedals visit us on the web at www.ehx.com Email us at
info@ehx.com
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.
References
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>