Electro-Harmonix Sovtek Deluxe Big Muff Pi User manual

Sovtek Deluxe Big Muff Pi
Congratulations! You have just purchased the passionate lovechild of our revered Green
Russian Big Muff Pi reissue and the Big-Muff-on-steroids Deluxe Big Muff Pi: the Sovtek
Deluxe Big Muff Pi! We know what you’re thinking – “Oh, no, they didn’t!” Oh, yes, we did!
It’s the beefy, woolly tone you love from the Green Russian Big Muff with all the bells and
whistles from the Deluxe Big Muff. Check it out.
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 hiss and hum
Blend –allows you to mix the dry signal with the distortion
Wicker switch –opens up the high end for extra attack
Expression Pedal Input –sweep the frequency of the MIDS EQ with your foot
True Bypass
CONTROLS
VOLUME Knob –Works as a master volume control for the entire pedal
BLEND Knob –This mixes between the dry and distorted signals. Turn this knob fully
counterclockwise for 100% dry signal and fully clockwise for 100% wet signal. Setting the
BLEND knob to noon yields a 50/50 mix of dry/distorted signal.
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
Wicker Switch –This feature is the same as the switch found on the Big Muff Pi with
Tone Wicker. With the switch up, the wicker is engaged and high frequency bandwidth is
opened up for a bright and clear top end and more pronounced attack. With the switch
down, the effect is disengaged and the Big Muff circuit is back to stock.
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 Sovtek 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 Sovtek 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with the input buffer off. The input impedance is 1M with the input
buffer on.
OUTPUT –This is the output of the Sovtek 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 other 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 the 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 Sovtek 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 9.6DC-200BI (same as used by Boss™ & Ibanez™) and delivers up
to 200mA at 9.6 Volts DC. The actual current draw of the Sovtek Deluxe Big Muff is 22mA
at 9VDC. The AC Adapter must have a barrel connector with center negative plug. The
Sovtek 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 Sovtek
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 Sovtek 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 INPUT BUFFER SWITCH & TRIM POTS
We have included an internal slide switch to engage a buffer on the input to the Big Muff
circuit. Engaging this buffer will increase the high end content of both the distorted and
clean signal being blended in. The slide switch is located near the input jack and is set to
the “unbuffered” position at the factory. Be careful not to touch any other components
when adjusting this switch.
The Sovtek 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 knob-side-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 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 [phone]. 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 Europe
EHX CUSTOMER SERVICE JOHN WILLIAMS
ELECTRO-HARMONIX ELECTRO-HARMONIX UK
c/o NEW SENSOR CORP. 13 CWMDONKIN TERRACE
55-01 2ND STREET SWANSEA SA2 0RQ
LONG ISLAND CITY, NY 11101 UNITED KINGDOM
Tel: [phone] Tel: [phone]
Email: [email protected] Email: [e-mail]
The CE logo indicates that this product has been tested and shown to conform
with all applicable European Conformity directives.