With the BM-17 Frequency Box, Behringer presents a clone of the Moog MF-107 FreqBox from the popular MoogerFooger range. Behringer has succeeded in faithfully reproducing the distinctive sound of this classic in every detail.
The BM-17 is a fully analogue effect unlike almost any other; essentially, it is an oscillator designed to be coupled to any input signal. The oscillator itself has a wide frequency range and is equipped with the rare feature of a continuously variable waveform. The waveform can be set from triangle to sawtooth and square, right through to spike. When Hardsync is activated, the oscillator attempts to synchronise with the frequency of the input signal. The ENV and FM AMOUNT controls bring a degree of order to the chaos. FM AMOUNT determines the extent to which the input signal affects the oscillator’s frequency. The envelope follower converts the level differences in the input signal into a control voltage and uses this to modulate the oscillator’s frequency.
Despite its minimal number of controls, the effects pedal takes a little getting used to. The results range from wild squealing interludes, rhythmic drones, electronic percussion, classic sync sounds, and basslines that pop up between the level peaks of a drum machine. But the BM-17 is also highly useful as an additional oscillator for a synthesiser or as a modulation oscillator for filter FM. The input stage is designed for line and guitar levels and can be overdriven; in most cases, this sounds very musical and has a harmonic character.
The connections are the same as on the original: there are five CV/expression inputs for the parameters Frequency, Waveform, Envelope Amount, FM Amount and Mix. This allows the parameters to be controlled via an expression pedal or by any control voltages from the modular system. The audio inputs and outputs are mono. The envelope follower is routed to the ENV OUT and can thus serve as an additional modulation source for other instruments with a control voltage input. The same applies to the oscillator, which is routed to OSC OUT and can be used elsewhere in the patch as an additional tone generator.


Behringer BM-17 Frequency Box