Radial Engineering Firefly User Manual

Radial™ Smart Sheet

Order No. R800 2020

FIREFLY

™

TUBE DIRECT BOX AND PREAMP

The Firefl y is a 12AX7 tube direct box, designed to facilitate liver performance while delivering
studio quality audio. Selectable A or B inputs with separate level controls enable the user to
switch between tow basses, or acoustic guitars quickly between songs. A variable low cut (high
pass fi lter) lets you ‘size the instrument by reducing low frequency resonance. This helps clean
up the mix and reduce feedback. Drag control load correction further enhances the functionality
by allowing magnetic pickups such as found on a Fender bass to be optimized. Turning off the
Drag control raises the input impedance to 4 meg-ohms to smooth out the squawk and peaks
common to piezo pickups. The rear panel features stacked ¼” inputs, TRS insert and a thru
connector for the stage amp. A separate tuner output works with the optional JR2 footswitch to
remotely switch channels and mute the system for quiet on-stage tuning.

Features

• Dual input with optional remote footswitch

• 12AX7 tube drive stage for warm tone

• Transformer output to eliminate noise

• Variable high-pass resonance fi lter

Applications

• Perfect front end for recording bass direct

• Piezo ready to capture upright bass or acoustic

• Ideal for recording and live performance

• Add analog tube warmth to instruments

Cool Factors

• Can be rack mounted for concert touring

• Ultra-effi cient switching between instruments

• Sounds absolutely amazing

• Looks great too!

POL 180°: Polarity inverts the XLR
output to reduce resonant peaks
that cause feedback hot-spots.

GROUND LIFT: Disconnects pin-1
at the XLR out. Helps reduce noise
caused by ground loops.

AUX PRE/POST: When set to the inward position (pre) the ¼” AUX
OUT provides a clean buffered feed from your instruments with a
fi xed level. When set to the outward position (post) the AUX OUT
is processed like the XLR output and includes the tube stage, fi lter
section, insert loop and variable level control in the signal path.

TRIM-A & B input level controls
used to match the gain be­tween the two instruments.

MUTE LED indicates when the
mute function is active via the
optional JR•2 footswitch.

LOCKING 5-pin XLR
power connection for
external supply.

ISOLATED output
eliminates hum & buzz
caused by ground loops.

SELECT switch toggles
the active input for fast
instrument changes.

ON/OFF toggles between Drag
control or fi xed 4 meg-ohm
impedance for piezo pickups.

BALANCED XLR output
connects to the PA or
recording system.

JR•2 REMOTE connection
selects the active input and
mutes the Firefl y for tuning.

DRAG™ retains natural
tone by adjusting the
load for passive pickups.

TUNER out is always­on for connecting an
electronic tuner.

INSERT efx-loop to
interface guitar pedals
and studio rack effects.

MASTER LEVEL
control is variable from
mic-level to line-level.

VARIABLE LOW-CUT fi lter
rolls off bass resonance that
can cause feedback.

AUX OUT high-Z thru for
stage amp. Confi gurable
pre or post tube and insert.

DUAL INPUTS lets you switch
between two instruments for
quick on-stage changes.

Switching between passive & active basses Firefl y with acoustic guitar & mandolin

Tuner

The Firefl y is equipped with two inputs and
level controls to make switching between active
and passive basses easy. Add the JR2 remote
control for added switching convenience.

Radial Engineering Ltd. • DI & Interface Series Smart Sheet © Copyright 2012 all rights reserved · www.radialeng.com · email [e-mail] • Subject to change without notice • Made in Canada

FX loop

The Firefl y is perfectly suited for doubling
on stage using two acoustic instruments.
The 4 meg-ohm piezo input enables direct
connection without a preamp.

Firefl y with an upright & electric bass

Whether you are connecting via a pickup/
preamp combination or just direct from the
passive piezo, the Firefl y is perfect for string
instruments. Use the variable high-pass fi lter
to eliminate low frequency resonance and
feedback.