Germany's Vermona are no strangers to pure analog devices. Everything in their product list is a beast. Needless to say, I was pretty excited when the knob-laden Perfourmer MKII showed up. As its name indicates, this is a four voice synth, each with its own set of controls on the large front panel and individual outputs as well. A CV/Gate option can be added to the back panel for connectivity to a modular setup.
Although the design of each channel is the classic VCO/VCF/VCA structure, the sound palette of this synth is extremely deep. It shines on everything from basses to leads to percussion. Synthesis begins with a VCO that offers four wave shapes (sine, triangle, square and saw) as its sources. Noise and external input are also options. That's right, this bad boy can function as a powerful four-channel filter bank as well. There are four octave choices (32', 16', 8', or 4') as well as fixed frequencies called HI or LO which are useful for modulating. (More on that later.) In the VCO section, an envelope intensity knob labeled EG INT can be turned either positive or negative to modulate pitch—this is where percussion is created. Each oscillator can be tuned about seven semitones in either direction with glide available as well. An LFO intensity knob turned left modulates frequency, and to the right, pulse-width (when working with square waves).
The VCF section is pretty straightforward with controls for cut-off, resonance and LFO depth (labeled INT). The filter is a 24db low-pass design and sounds incredible. Another EG INT knob is seen in this section for assigning the ADSR envelope to modulate the filter. A three position switch selects the amount of filter-tracking to make the cutoff increase as you travel up the keyboard. When self-oscillating the filter with a high resonance, you can play actual notes when tracking is engaged, creating yet another sound source that's great for sci-fi. The VCF can be modulated by the envelope, aftertouch or the LFO. The very basic LFO section is comprised of a speed knob and a switch that chooses from saw, square, sine or sample and hold (random). The LFO clock can be synced to MIDI beat clock as well as tapped in internally.
The also-simple VCA section has a switch that selects between three modes. EG looks to the ADSR envelope for its shape, GATE is a fixed envelope with instant attack and release times like an organ, and ON leaves the VCA constantly on, which is useful when producing a drone or going to further processing. Finally a pan knob for the stereo outputs and a volume knob complete the section.
To the far left of the front panel there is an interesting section which allows successive VCOs and LFOs to be synced as well as be used for frequency modulation of the VCOs and VCFs. For example, all four voices can have their frequency synced together, or the LFO of channel two can be synced to the LFO of channel one while channel three modulates the frequency of channel four and so on. When syncing LFOs, the LFO speed knob becomes a phase knob with a range of 0-180 for interesting modulation effects. Although the Perfourmer is essentially four mono synths in one, they can be used in several ways together with extensive modulation possibilities. There are six different play modes that determine how the Perfourmer responds to incoming MIDI notes. In Mono 1 mode, all four channels are treated as a single monophonic synth. Here it is possible to stack them on the same MIDI channel or have them receive different channels for a four-synths-in-one effect.
In Mono 2, they are triggered in succession, like a round robin effect commonly seen on old synths, however, since each channel has its own VCO, VCF and VCA settings, this can be very interestingly used with a sequencer and/or arpeggiator. Two Duo modes turn the Perfourmer into two two-voice synths, one for alternating and one for simultaneous playback. Two Poly modes allow up to four voices to be played simultaneously, with one mode storing held notes while the other does not. Again, these six play modes attest to the versatility of the Perfourmer. Completing the front panel are knobs for master tune and master volume with a headphone jack. There is also a 16-position knob that determines MIDI channels and selects between the ten parameter settings that are customizable per channel including pitch bend, mod wheel to PWM, LFO sync and a few more standard controls. Each channel has 2 TRS jacks on the front panel that give access to external input/VCO direct output and individual channel outputs/insert. On the back are MIDI IN and THRU ports, stereo Â¼" master outputs, and holes for the optional CV/GATE expansion.
The Perfourmer excels in all departments. It is built well, the knobs feel great, and the layout is straight forward. The sound is huge, raw, analog and beautiful. And by design it is extremely versatile, functioning as a four voice poly-synth/drum machine, four individual mono synths, two two-voice synths, or as a processor for external sounds through its fat filters. When paired with the right sequencer, this is a synth junkie's dream.