Tech 21 Boost Chorus Owner`s Manual

*Utilizes standard 9V alkaline battery (not included). NOTE: Input jack

POWER REQUIREMENTS

activates battery.To conserve energy, unplug when not in use. Power
Consumption: approx. 50mA, for battery life of approximately 10 hours.

*USE DC POWER SUPPLY ONLY! Failure to do so may damage the

unit and void warranty. DC Power Supply Specifications:

-9V DC regulated or unregulated, 100mA minimum;

-2.1mm female plug, center negative (-).

Optional factory power supply is available: Tech 21 Model #DC2.

WARNINGS:

* Attempting to repair unit is not recommended and may void warranty.
* Missing or altered serial numbers automatically void warranty. For your own

protection: be sure serial number labels on the unit’s back plate and exterior
box are intact, and return your warranty registration card.

ONE YEAR LIMITED WARRANTY. PROOF OF PURCHASE
REQUIRED. Manufacturer warrants unit to be free from defects in materials

and workmanship for one (1) year from date of purchase to the original purchaser
and is not transferable. This warranty does not include damage resulting from acci­dent, misuse, abuse, alteration, or incorrect current or voltage. If unit becomes
defective within warranty period, Tech 21 will repair or replace it free of charge.
After expiration, Tech 21 will repair defective unit for a fee.

ALL REPAIRS for residents of U.S. and Canada: Call Tech 21 for Return
Authorization Number. Manufacturer will not accept packages without

prior authorization, pre-paid freight (UPS preferred) and proper insurance.

FOR PERSONAL ASSISTANCE & SERVICE:

Contact Tech 21 weekdays from 10:00 AM to 5:00 PM, EST.

MADE IN THE U.S.A.

Tel: [phone] / Fax: [phone]
www. tech21nyc .com / info@tech21nyc .com

©20 11 Tech 21 USA, Inc.

OWNER’S MANUAL

TECH 21, THE COMPANY

Tech 21 was formed by a guitarist possessing the unusual combination of a trained ear and
electronics expertise. In 1989, B. Andrew Barta made his invention commercially available to
players and studios around the world. His highly-acclaimed SansAmp™ pioneered Tube
Amplifier Emulation in professional applications for recording direct and performing live, and
created an entirely new category of signal processing. There have since been many entries
into this niche, yet SansAmp continues to maintain its reputation as the industry standard.

With a full line of SansAmp models, Tech 21 also offers effect pedals and MIDI products, as
well as “traditional” style amplifiers for guitar and bass. Each product is thoughtfully and
respectfully designed by B. Andrew Barta himself with the player in mind. Our goal is to pro­vide you with flexible, versatile tools to cultivate, control, refine and redefine your own indi­vidual sound. Tech 21 takes great pride in delivering consistent quality sound, studio to studio,
club to club, arena to arena.

PRODUCT OVERVIEW

Derived from the careful study of ‘70s choruses, the Boost Chorus pedals combine studio-grade
performance with unique effect combinations to create thoroughly modern options. Each offers
an unusual amount of flexibility to achieve a variety of choral effects, including any array of
entertaining, yet cleverly useful, never-before-heard sounds.

The different designs address different and inherent needs of guitar and bass players. However,
either pedal can be used on either instrument, as well as any number of other instruments.
Experimentation is always encouraged!

The Boost Chorus features a Pre-Delay control, which alters the delay range of the chorus
effect. For the Bass Boost Chorus, we took a different approach. It features a Detune control
to adjust the pitch of the choral voicing, adding sonic girth to create thick, lush, bass-compati-
ble chorus. While Speed and Depth controls add modulation, you can set them at minimum to
preserve the fundamentals. This avoids that queasy, seasick feeling typically associated with tra­ditional chorus pedals when used on bass.

Both Boost Chorus pedals feature a Multi Voice switch, which increases dimension with addi­tional choral voicings.

As with each Tech 21 product, the controls are designed to give you the flexibility to obtain
your desired sound. It is our hope that the Boost Chorus and Bass Boost Chorus will be use­ful tools for stimulating your creativity and, ultimately, providing the inspiration to play your
best.

THE INS AND OUTS

1/4” INPUT: 1megOhm high impedance input, same as traditional tube amps. Also

switches battery power on/off. To avoid battery drain, unplug when unit is not in use.

1/4” OUTPUT: 1kOhm low impedance output drives long cables without loss of signal

integrity, even in bypass.

SIGNAL LEVEL TO INPUT/CONNECTIONS

The Boost Chorus pedals are designed to accommodate instrument level signals to the Input, such
as the output of a guitar/bass, distortion pedals, etc. For normal operation, signal level to Input
should be close to that of a standard electric guitar/ bass (approx -10dBm / 250mV). Line level sig­nals will not damage the Boost Choruses, however the resulting sound may not be particularly
desirable.

PRE-DELAY

Sets the delay time of the chorus, ranging from 0-50 milliseconds, giving you a wide range of
flexibility. Below one o’clock emulates a 512-stage bucket brigade. Above one o’clock emu­lates a 1024-stage bucket brigade and beyond.

0-10 = flanging/vintage chorus

(512-stage bucket brigade)

10-30 = ‘80s chorus

(1024-stage bucket brigade)

30-50 = doubling/slapback echo

(1024+-stage bucket brigade)

Multi Voice

Adds additional choral voicings. To engage, push the switch in. This creates 3 choral voices
with 90 degrees of separation that “chase” each other. Rather than hearing a typical sweep,
this gives you a more natural choral personality and is more compatible with distortion.

GUIDE TO CONTROLS - Bass Boost Chorus

GUIDE TO CONTROLS - Boost Chorus

DETUNE (Bass Boost Chorus)

Shifts the pitch of the choral voicing up or down. At unity (12 o’clock), there is no pitch
shifting. The Detune control enables you to have a chorus sound without any modulation
when Speed and Depth are at minimum. Note: This control functions differently depending
on the orientation of the Multi Voice switch:
In Single Voice mode: As you increase Detune, the pitch goes up/sharp. As you
decrease, the pitch goes down/flat.
In Multi Voice mode: Detune controls the pitch of 2 voices. As you increase Detune, one
voice goes up/sharp and one voice goes down/flat. As you decrease, one voice goes down/flat and
one voice goes down/flat in smaller increments.
Detune Setting Tip: for vintage chorus sounds, set Detune at 12 o’clock and use Speed
and Depth to add modulation.

GUIDE TO GENERAL CONTROLS

SPEED

Controls the speed of the modulation from .2 Hz to 10 Hz.

DEPTH

Controls the depth of the modulation. A minimum setting will give you a subtle effect. As
you increase, it will become more and more “wobbly.”

TONE

100% analog circuit. Affects the tone of the delayed signal only. Unity gain is at the indicator
arrow and will have no effect on the signal. Increasing the setting will give you a treble boost
for a snappy ’80s chorus sound. Decreasing the setting will give you a treble cut, yielding a
darker analog chorus sound.

MIX

100% analog circuit. Controls the ratio of direct and modulated signal. While most chorus
pedals provide a preset 50/50 mix ratio, the Tech 21 Mix control offers a sweep from 100%
dry to 100% wet for a vibrato effect. This gives you more flexibility when you want to run
through a parallel effects loop without annoying phase cancellation.

LEVEL / BOOST

100% analog circuit. Not commonly found on chorus pedals, this control adjusts the overall
output level to ensure against the typical drop in volume when the pedal is engaged. Increasing
from unity gain provides additional boost, up to 3dB or 9dB depending on your other settings.
Level tip: If you have a 100% wet signal going through a parallel effects loop, use the Level
to adjust the mix of dry and effected signal.

2

BYPASS

Buffered bypass eliminates the shortcomings associated with “true bypass” (pops and clicks,
and high-end loss when multiple pedals are connected together), as well as signal loss associ­ated with other types of switching circuits.

PLACEMENT NOTES

The general rule of thumb with time-based effects, is to place them last in the signal chain.
Here are some points to consider:

1) Into an amp’s effects loop. This will give you the cleanest, most true representa­tion of the effect because it is last in the chain --after the amp’s tone shaping, compression
and distortion. It is the closest way to replicate how choruses are used in a recording studio.

NOTE: Some amplifier effects loops are line level, which may cause the Boost Choruses to distort.
It will also compress the signal and reduce the output. The same may hold true for mixing boards.
Therefore, you may need to obtain a level matching transformer.

2) After an amp emulator (such as a SansAmp) or distortion pedal into an
amp. Set your amp completely clean to achieve similar results to running through an effects

loop.

NOTEWORTHY NOTES

1) Stereo imaging for a ‘70s jazz chorus sound. With, for instance, two Tech 21
Trademark 60 combo amps, plug your guitar into one amp, use the Effects Send to the
Boost Chorus set at 100% wet. Then run the Boost Chorus to the Effects Return of the sec­ond amp.

2) The Boost Chorus pedals are very responsive. Our controls are unusually
sensitive and tend to perform well beyond what would be considered “normal.”

3) LED indicator light. When battery runs low, the LED will become noticeably dim.
Power consumption is 50mA. With a fresh battery, you can expect the Boost Chorus pedals
to operate for approximately 10 hours of continuous use --more than enough for a full gig.
To conserve battery life, unplug the unit during breaks and any other time it is not in use.
We recommend opting for a power supply, as it is environmentally-friendlier, will ensure
operation, save money on batteries, and relieve stress trying to remember when you last
changed the battery.

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