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User Guide

Instrument Amp: Clean or Character

To make the Firefly fexible we gave the hi-z output "PRE and POST" modes that allows you to choose between a clean buffered instrument signal (PRE) or the same signal path and tone as the main XLR output. The recessed AUX-PRE/POST switch is used to select the mode for the ¼" AUX OUT.

The AUX OUT can be set to pre or post using the recessed switch.

When pushed inward the hi-z AUX OUT jack is a super-clean buffered output that skips most of the Firefly's processing (PRE-tube/efx-loop/low filter) and offers a fixed output level. This PRE mode is good when you want to split the insrument signal and send it on to another device that needs a clean signal.

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When the AUX Pe/Post switch is set to the outward position (POST) the hi-z AUX OUT shares the same signal path and all of the sonic character as the main XLR output. In this mode the level is variable and adjusted by the MASTER control on the front panel. Using the hi-z output in POST mode allows you to feed an on-stage amp with the same sound as is sent to the FOH console via the XLR out.

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With this in mind it is recommended you start listening to the Firefly's full tube circuit using the factory defualt POST setting.

Firefly™ Tube DI Using & Applications

The following is a short 'how to approach the Firefly Tube DI' guide for those familiar with direct boxes in pro audio situations. For more information, we invite you to download the manual. (PDF download)


Firefly is an instrument direct box with a tube drive stage and transformer output. Thanks to the tube stage and high voltage FET buffers the Firefly can be considered both a mic-level and line-level device. In other words, it's a DI with GAIN! This is a departure from a traditional DI box with a fixed mic-level output.

Because the Firefly's MASTER level control allows the output to be continuously adjustable from infinity (off) to +22dB you can connect the Firefly to a wide range of inputs. At lower settings you can connect the Firefly to a console's microphone inputs. At higher output settings the Firefly has enough gain to overdrive the input of tube amp or even drive a power-amp. In this section we will be taking a look at different setups for studio and live performance.

Making connections

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This is a typical setup for live and studio use. Dual inputs with dedicated level controls is especialy helpful for level matching active and passive instruments for quick change-overs. To further the convenience, the optional JR2 remote footswitch can be added for channel switching and silent tuning.

On the output side of the Firefly, hi-z ¼" jacks connect to an instrument amplifier and an electronic tuner. The main balanced XLR output is controled by the Master level control and, as mentioned, is variable allowing the Firefly to connect to mic and line inputs.


Switching between passive & active basses

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TRIM-A & B are used to match
levels between instruments.

With the multi-instrumentalist in mind we gave the Firefly dual inputs with independant level controls. The dual controls let you adjust the levels of the instruments to match. When instrument levels are matched switching from one instrument to the other is seamless.

This setup has advantages for the live performaning artist. The classic example is a player who has an active 5-string and a passive Fender Jazz bass. The active pickups in the 5-string will make the instrument seem louder than the passive Jazz bass.

Here the appoach would be to first connect the "quieter" of the two instruments and setup your amplifier and PA or recording system. Once thats done it's a simple matter of dialing back the TRIM control for the louder instrument to match the quieter one. Now, when switching between instruments, the output levels are consistant making for seemless transitions between instruments. Add the JR2 remote control for added switching convenience.


Using the Firefly with an piezo pickup

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When Drag Load Adjust is turned off the input impedance is automaticaly increased to 4meg Ohms which allows piezo transducers to sound their best.

The Firefly offers a variable input impedance control called Drag™ Control. When turned on it can be adjusted for the optimal input impedance for the pickups of your instrument.

However, turning off Drag control engages a "perfect-for-piezo" fixed impedance of 4meg Ohms. This super high impedance does not affect the sound of magnetic or active pickups but it does allow the piezo transducer to pass the widest possible frequency response and dynamic range making the Firefly an excellent preamp for acoustic instruments like string bass or mandolin.

In this setup for the live performing artist the player has an Fender bass with magnetic pickups and string bass with a piezo transducer. The Drag control has been turned off to setup a fixed 4meg Ohm input making piezo sound clean and responsive compared to an amplifier where 1meg Ohm is the typical input impedance.

To further assist acoustic instrumetns the Firefly includes a LOW-CUT filter. When set to minimum it is effectivly out of the signal chain. When turned clockwise the filter will start to attenuate low frequencies. The filter can help reduces run-away resonance feedback on stage.