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Vermona DAF1 & PH16

Analogue Filter & Phaser
By Paul White

These two new rack processors from Vermona offer flexible filtering and phasing with a range of interesting modulation options.

Vermona might sound like the name of a quaint Italian village where myopic old gents in leather aprons (who I fondly imagine look something like Pinocchio's creator) lovingly turn out handmade violins, but it's actually a German company specialising in analogue signal processing.

Vermona DAF1 & PH16.Photo: Mark EwingVermona's 1U rackmount DAF1 Dual Analogue Filter is designed to be used as an add-on to synthesizers or other sound sources. At its heart is a pair of analogue filters that can be configured in band-pass, parallel, notch or serial modes. Depending on the setting of the four-way Mode switch, the filters are configured automatically as high-pass or low-pass as required to produce the selected response. Each of the two filters has a separate Resonance control and, in parallel mode, this enables an unusual response curve to be set up that has two different resonant peaks. The cutoff frequency for the two filters is also individually adjustable (except in series mode, where both filters are controlled by the first filter's knob), so in band-pass and notch modes the width of the combined filter response depends on where you set their respective cutoff frequencies.

Both filters can be modulated by an external CV voltage or by an onboard LFO, with the further option of using an expression pedal connected to the CV input. When nothing is connected to the CV input (which accepts signals in a ±5V range), the unit is able to follow the input signal's envelope and use this to modulate cutoff frequency. The LFO is a simple triangle-wave affair with Speed (0.05Hz to 25Hz) and Intensity controls, but it has four selectable choices of destination: F1, F2, F1+F2 and F1-F2. In the 'plus' mode, both filters are modulated in the same direction, while, in the 'minus' mode, the cutoff frequencies are modulated in opposite directions. The same destinations are available for the CV/Pedal input, with a variable Intensity control. An input Gain control and Clip LED are used to optimise the input level (important when the envelope-following modulation mode is in use) and a further control sets the output level.

Vermona DAF1 & PH16 £194 / £188
pros
  • Easy to operate.
  • Full stereo signal path.
  • Slightly quirky, in a creative way.
cons
  • No MIDI triggering, and envelope-following effects are sometimes unpredictable.
summary
Both these boxes offer a good balance between ease of use and creative potential, provided that you remain aware of their limitations.

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To accommodate stereo sources, such as digital synths, the DAF1 features a fully stereo signal path, accessed by unbalanced jacks on the rear panel. It may also be used in mono, by using just the left input jack, or it may be used with high-impedance mono sources, such as guitars, via its front-panel jack. It's also possible to feed a stereo signal into the unit on a TRS jack using the right rear-panel input only. Further rear-panel jacks accept a bypass footswitch (though there's also a Bypass button on the front panel) and an external CV input. The manual shows how the connection should be wired to allow a regular volume pedal to operate via the CV input, though any voltage source within the permitted ±5V range may also be used.

I tested the DAF1 with my ancient Yamaha SY35 keyboard, which has no filters on board. It certainly brings some of the sounds to life, but you have to be a little careful using the envelope-following mode, as sounds that have a lot of modulation in their decay cause the filter frequency to modulate unpredictably and sometimes quite wildly. Occasionally this sounds good, but there are some source sounds where the end results are too chaotic.

The LFO on both the DAF1 and PH16 can modulate the two channels of processing in a variety of ways.The LFO on both the DAF1 and PH16 can modulate the two channels of processing in a variety of ways.Photo: Mark EwingLFO modulation is, naturally, very stable and predictable, but what the unit lacks is a MIDI trigger input that would allow reliable triggering from MIDI Note On messages, regardless of the nature of the sound being processed. The filter Resonance controls can be turned up to the point of self-resonance, so you can get some quite fierce sounds as well as polite ones. Despite the lack of MIDI triggering, there are some great sounds to be had, and where you have the filters moving in opposite directions, even simple source sounds can be made to appear rich and complex. Of course, CV triggering from an older analogue synth would also be predictable in operation, but I can think of few analogue synths that don't already have perfectly adequate filters.

PH16 Dual Analogue Phaser

The PH16 is packaged in the same slim rackmount case, with similar I/O options, and again can be controlled by CV or envelope follower. The all-analogue phaser section can be switched for up to 16 stages of phase-shift and can handle stereo signals. Like the filter, the processing section has a dual topography, this time with two multi-mode phasers. A single six-way rotary switch sets the phaser mode for both phasers, as follows:

  • Position one (4ST Parallel): independent parallel phasers with four phase-shift stages each.
  • Position two (6ST Parallel): independent parallel phasers with six phase-shift stages each.
  • Position three (8ST Parallel): independent parallel phasers with eight phase-shift stages each.
  • Position four (8ST Serial): serial phasers with four phase-shift stages each.
  • Position four (12ST Serial): serial phasers with six phase-shift stages each.
  • Position four (16ST Serial): serial phasers with eight phase-shift stages each.

Each phaser has its own resonance control for applying more feedback and each has a manual phase-shift control. The amount of phase-shift may also be modulated from a variable-speed, variable-depth LFO which is broadly similar to that in the filter unit insomuch as it can be routed to P1, P2, P1+P2, P1-P2. The CV/EF section also has an Intensity control plus a Destination selector offering the choices of P1, P2, P1+P2 or P1-P2, Speed or Intensity. An output Mix control sets the balance between the processed and dry sound and there's a Bypass button as well as a TRS jack on the rear panel that can accept a double footswitch for bypass and LFO defeat.

Both the DAF1 and the PH16 have six jack sockets on their rear panels, two for inputs, two for outputs, and the final two for CV and footswitch inputs.Both the DAF1 and the PH16 have six jack sockets on their rear panels, two for inputs, two for outputs, and the final two for CV and footswitch inputs.Photo: Mark EwingSo is this phaser set to 'stun'? Each of the modes does sound very different, with some applying an almost vocal, formant-like quality to the sound, while others verge on mild flanging. You can get the usual phaser pedal effect of course, but the PH16 goes way beyond that and provides a means to add colour and movement to just about any harmonically rich source. Because we're more used to hearing phasers controlled by LFOs, the envelope-following issues discussed when testing the filter are less important and, indeed, being able to add some kind of chaotic phase shift to the regular LFO modulation can produce more organic results than LFO alone. Furthermore, the fact that the CV input or envelope follower can also modulate the LFO depth or speed is interesting.

Vermona Verdict

Both these processors sound good and are just quirky enough to offer something a little out of the ordinary. I've never been entirely convinced by add-on filters for use with synths, because modern synth filters are, of course, polyphonic. Furthermore, unless MIDI triggering is used, the shape of the filter modulation envelope depends very much on the nature of the sound being processed, and whether the notes flow into one another or whether they are short and separate. Even so, either of these units can be used to coax new and unusual sounds out of existing instruments, so if you prefer hardware to plug-ins and enjoy experimenting then there's a lot of fun to be had with either of these units.

information
infop.gif DAF1 filter £194; PH16 phaser £188. Prices include VAT.
infot.gif Analogue Solutions +44 (0)1384 353694.
infow.gif www.analoguesolutions.com
infow.gif www.vermona.com
Published February 2003