The Electro Harmonix Synth 9 : Synth Pedal for Guitar

My own personal Rick Wakeman...

Rating:
Guitar synthesis for the masses, without the hassle.

The ElectroHarmonix Synth9 is the latest addition to Electro Harmonix's synthesis pedals, following the Organ sounds of the B9, the Rhodes/Wurlitzer sounds of the Key9 and the Mellotron-inspired Tape9. These pedals are an amazing way to expand the sound palette of your guitar, without the expense and hassle of attaching hexaphonic MIDI pickups to your guitar and spending thousands on guitar synth engines, most of whose sounds you will not use.

I bought the Electro Harmonix Synth9 as I play in a duo that occasionally covers 80s tunes such as Kraftwerk's The Model or Eurythmics Sweet Dreams. I needed to be able to play a convincing synth bass or a nice sawtooth lead line here and there. Most of the synth pedals I have tried until now were essentially useless - the tracking was usually so poor that a descent into warble-madness was never far away unless you played like a robot and lost all groove in the process. The closest I ever got to the sound I needed usually involved some combination of an octave pedal followed by an envelope filter and a fuzz, but it alway left something to be desired.

So I was impressed when I saw youtube demos of the latest Electro Harmonix pedals  - they seemed to have no tracking issues and sounded very convincingly like the devices they were emulating - there was no hint of cheesy General MIDI ROMpler sound to them. How they are doing this I can't say  - I suspect there is some sort of algorithm that is able to determine what notes are being played polyphonically and then use its synth engine to generate these same notes - whether, with some version of wavetable synthesis, physical modelling or virtual analog oscillators, I don't know.

What I do know is that it works - you can simply plug your guitar into one of these, and out the other side, with no discernable latency or issues comes the polyphonic sounds of a dream studio's-worth of analogue synths - from the Prophet 5 to a Minimoog to the Korg Polysix.

Wisely, given the complexity of the devices that this pedal emulates - EHX has decided to make things simple on the poor guitar player - a rotary switch selects between the 9 synth types - and 2 control knobs change the most important aspects of whichever sound is selected. So when the pedal is set to the Prophet 5 setting, for example, Ctrl 1 changes the filter sweep time, and Ctrl 2 changes the Octave of the synth sound. When set to the ARP String Synth sound, Ctrl 1 changes the tone of the sound and Ctrl 2 sets the attack time. This scheme makes it relatively easy to dial in the sound you want without having to get too deep into the ADSR envelopes, filters, LFOs and so on that make up the synth sounds.

After a few minutes, I had essentially found the setting that I needed to play the synth riff from Sweet Dreams - not surprisingly the Prophet 5 sound on Preset 2. Electro Harmonix has chosen a good general selection of the analogue synth sounds you're most likely to want to have in your arsenal - from solid synth bass to 303-esque squelch, to the classic ARP String Synth. A nice feature is that if you continue strumming after triggering a synth sound it responds as if you were holding down the keys on a keyboard, and you can use the sounds as if they were pads. This can be useful for general atmospherics.

You can also mix in the direct sound of your guitar with the synth sound using the Dry knob. There's also a dry output jack - which could allow you to put your dry guitar sound though various effects and amp sims, while the synth goes through a different effects chain. The Synth9 pedal also works with bass guitar - though the tracking isn't guaranteed down past the low A of a standard 4-string. This is no matter though, as the synth sounds you'll be triggering can be at whatever octave you like - so you can simply play your riffs a little higher up on the bass.

Electro Harmonix recommends using this pedal at the beginning of your chain for optimum triggering, which makes sense, but this doesn't mean you can't put its output through as many effects as you like. The pedal contains an always-on compressor, which should help to prevent you from blowing out too many woofers with your dubstep wobbles, but I've  put it through phasers, tape-delays and reverbs to great effect - not to mention the pleasant nastiness of a dirt pedal or amp sim.

With a looper, you can go full Brian Eno and create all sorts of shifting ambient soundscapes if that's your thing. I can actually imagine the Synth9 being a very useful tool for soundtrack work - approaching synth sounds from a guitar angle can result in some amazing happy accidents - and the labyrinth of guitar pedals and amps you can route this thing though can sometimes result in more organic and, for want of a better word 'analogue' sound than computer-based softsynths.

In short, Electro Harmonix has created something really new with this pedal, to go with the other pedals in the 9 range. Guitar Synthesis no longer has to be the domain of people with deep pockets who don't mind poring through sub-menus. In a guitar marketplace where so many pedal manufacturers seem to be falling over each other to re-create 'vintage' and 'classic' stompboxes, this is a welcome development.