EHX Bass Mono Synth

The EHX Bass Mono Synth transforms your bass into eleven possible synthesizers. From vintage synth emulations to thick, stacked voices and deep sounds.

In the case of the Bass Micro Synth, we have within our reach a series of parameters that are responsible for directly modulating the signal of our instrument in a similar way that an analog synthesizer modifies a waveform. However, when creating the Bass Mono Synth, we have opted to provide the pedal with some preset sounds over which we can have some control. It is therefore a simpler pedal to operate and that also allows us to obtain a great result without any effort.

It is true that our ability to modify parameters has been reduced when compared to the Bass Micro Synth, but it is fair to say that the Electro Harmonix engineers have provided the Bass Mono Synth with sounds so good that you will most likely not miss that extra ability to control.


The Bass Mono Synth has been designed to work on a bass without modifications, special pickups, or MIDI implementation. Its intuitive design makes it easy to use. The pedal’s DRY pot adjusts the volume of the dry sound at the synth output, while SYNTH controls the volume of the synth sound at its output. Used together, they provide a good mix level.

SENS (Sensitivity) control adjusts how dynamics activate the synthesizer, and allows you to fine-tune the response of the pedal to bass equipment and the bass player’s playing style.

With the CTRL pot the bassist can adjust a tuning parameter for each of the 11 synth types. It varies according to the preset and provides an additional “fine adjustment.” There is also an EXP input that allows the user to control a completely different parameter in real time with an expression pedal.

EHX founder Mike Matthews commented, “From lush, warm sounds to high-pitched, percussive stitches, the Bass Mono synth puts a collection of great bass synths at your fingertips.”



With the exception of an emulation of the mythical Roland TB303 Bassline (Acid) and a faithful recreation of an ARP Odyssey (X-Fade), most sounds are reminiscences of analog synths from the late 70s or early 80s, especially the Roland SH-101, Jupiter 4 or ProMars with two oscillators in unison mode and sometimes with a Chorus effect to add depth. In the most aggressive sounds that almost seem to distort, the synth that our expert seems to approach is the Memory Moog, a monster with 18 VCO’s (3 per voice), a device that he knows very well. For our part, the preset called Sub reminds us a lot of the sound of the Boss OC-2 octave, a classic.


A pedal that with a minimum investment gives you access to 11 excellent sounds that in one way or another will give free rein to your creativity. It includes the power supply, but if you have to mount it on your pedalboard you will be happy to know that the voltage is the usual 9 Volts and that the consumption is more than reasonable, 125mA.


Leave a Reply

Your email address will not be published. Required fields are marked *