Source Audio Soundblox Pro Bass Envelope Filter

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THE FOLKS AT SOURCE AUDIO HAVE been turning heads with their innovative line of Soundblox effect pedals, and with the introduction of the SoundbloxPro series, they’ve taken some of their most popular devices and added depth, flexibility, and features that go way beyond the pedal’s original job description. The expanded capabilities of the SoundbloxPro Bass Envelope Filter bring it into a new realm—it’s a full-featured envelope filter, but it’s also a phaser, a graphic EQ, a wah-wah, and it allows you to store six presets. This pedal is too deep to simply plug and play—you’ll need to read the manual to get the best results. In an hour, however, I was able to get fluent with the unit’s multiple functions and able to create cool sounds that went way beyond my expectations.

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The effect knob on the Soundblox Pro BEF selects among an astounding 22 filter sounds: seven different 2-pole lowpass filters, four 4-pole lowpass filters, two single- peak filters, four triple-peak filters, two peak and notch filters, three phaser filters, and a filter bypass that accesses just the 7-band graphic EQ. Each filter has its own timbral signature and reacts with the other controls to provide a seemingly unlimited range of variation. But the Pro BEF ups the ante by adding a low-frequency oscillator as an optional modulation source. While an envelope follower modulates based on the dynamics of the input signal, the LFO sweep is not linked to the voltage of the input signal, and can be assigned different waveforms to vary the effect. The LFO rate is controlled by the SPEED knob, or via the TAP TEMPO function, which makes live synchronization a simple matter. In addition, the Pro BEF offers nine different LFO waveforms, including a user bank where you can download your own waveform—a feature accessible in BACKPAGE MODE, a stealthy set of menu options that greatly expand the unit’s functionality.

You can plug in a passive expression pedal and use it like a typical wah-wah or assign it to several other parameters. Modulation can also be controlled via Source Audio’s super-slick Hot Hand motioncontrolled technology. The player wears a special motion-controller ring that transmits even the slightest hand movement to a sensor plugged into the unit. The Hot Hand is a quirky controller that produces some stunning effects—and you’ll look like a groova-zoidal Gandalf summoning up the spirit of the funk while doing it!

You can assign the 7-band EQ either to the wet/dry blend or to the wet signal alone. Each
band has 12dB of boost or cut.
The SWEEP RANGE control determines the direction (up for “wah,” down for “ow”) and depth of the filter sweep, while the FREQUENCY KNOB sets the center frequency. The SPEED control adjusts the attack and decay time of the envelope filter, or the rate of the LFO. A new edition to the Pro BEF is the bi-directional MIX control that marks 12 o’clock as 100 percent dry signal. Turning the knob to the right increases the blend of wet signal, while left rotation increases the wet signal with the addition of LO-RETAIN, a function that speaks for itself.

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Another huge plus is the inclusion of a 7-band graphic EQ assigned to either the wet/dry blend, or the wet signal alone. Each band has ±12dB range, and an optional eighth band is available in BACKPAGE MODE that extends the EQ one more octave to 8kHz. The graphic operates perfectly, though at fi rst, I found the implementation of the LED readout tricky to grasp. The graphic display is also used to set various parameters in BACKPAGE MODE relating to expression pedals, Q depth, master volume, and MIDI channel.

To run the Pro BEF through its paces, I decided to fi ll the six preset banks with groovy sounds (three in envelope mode and three in LFO mode). Using a stumpy, downward envelope sweep on a resonant lowpass fi lter, I was able to nail the Herbie Hancock “Chameleon” vibe. To get a classic auto-wah sound, I called up a single peak filter with an upward sweep, using a fast attack, medium decay, and a goose at 125Hz and 250Hz with the graphic. A peak and notch setting gave me a similar auto-wah effect, but with a higher frequency range selected, and a bump at 4kHz, a watery top end appeared. In LFO mode, I took a triple peak filter that matched nicely with a 6-step triangle wave. By activating tap tempo, I got cool synchronized time-based effects that invited spacey harmonics. Dialing in the “For the Love of Money” tone is a true test of any phase pedal. Using one of the phaser settings with LFO, I bottomed out the SPEED control, put SWEEP RANGE at 1 o’clock, FREQUENCY at 3 o’clock and EQ’d a slight happy face in with the graphic—and it was right on the “Money.” Messing around with a peak-notchresonant lowpass filter with the sweep and frequency set to 2 o’clock, I conjured up a deep, spacey phase suitable for a lowbudget ’70s sci-fi flick.

The Source Audio SoundbloxPro Bass Envelope Filter is dynamite in a box. It can call up tons of classic envelope and phase tones, but also has the power to create new effects you have yet to imagine.

Street $219
Pros Great sound quality, deep feature set
Cons Not for plug & play types

Processor 56-bit DSP, SA601, 24-bit converters
Controls Sweep Range, Frequency, Filter Select, Speed, Mix, three preset footswitches, Tap Tempo
Modulation Sources Envelope, LFO
Graphic EQ ±12dB @ 62Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz (option)
Waveforms Sine, Rising Saw, Rectified Sine, Square, 4-Step Saw, 4-Step Triangle, 8-Step Triangle, Random Steps, 6-Step Triangle (user bank)
Power Supply 9-volt DC
Made in China

Warranty One year



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THE YEAR: 1976. WHILE MUCH OF Middle America was caught in a redwhite- and-blue reverie celebrating our nation’s bicentennial, Bootsy Collins and his interplanetary brothers in Parliament were busy shaping the future sound of funk. On his band’s single “P-Funk (Wants to Get Funked Up),” Bootzilla blew the bass world’s collective consciousness courtesy of a curious stompbox, the Mu-Tron III Envelope Filter.