John Bowen Solaris (by Brandon Daniel from Sunnyvale, CA, USA, via wikimedia commons)

As the synth addict I am, I’m completely overwhelmed by the machine John Bowen has designed. I had no occasion yet to put my hands on a real device. However, musictrackjp provides a great overview, regardless I do not understand japanese :) .

Even via the internet, one senses the organic character of its audio engine, e.g. by listening to the string sounds. In case you’re after a machine providing aggressive solo sounds, the fun starts at 10:30. If you know how to recreate this mooguesque sound using an Access Virus, a Korg Z1, or a Korg Kronos, please let me know.

The device emulates components (oscillators, filters) of several classic synthesizers from Sequential Circuits, Oberheim, Moog, and Waldorf. The latter emulation provides the original wavetables of the Microwave, which I sold about three years ago. A unique selling proposition are its two modulation rotors, which can be used for a lot of animations.

The price tag is almost 4k €, and it usually requires preordering. A lot of money for »just another subtractive synth«, though I presume it is worth every ¢.

For quite a while now, Korg put a lot of efforts in resurrecting some of their legacy machines. This includes, for example, the Wavedrum, the Polysix, and the MS-20.

The Kronos includes the latter two as software engines. While the emulations sound pretty good, I have a hard time getting used to the MS-20 emulation, due to the behaviour of its second envelope generator. A couple of resources (like the ones here and here) shed a little light on the issue. There’s a wee small hint provided by the imprints of the patch panel.

A closer look at the reverse output of envelope generator two indicates that the sustain stage of the envelope provides a voltage of 0 V.

As a consequence, increasing the sustain level will not increase the filter’s cutoff level as it does on many other machines. Instead, it decreases the filter’s level during the attack, hold, decay, and release stages.

Per default, with no patching implied, the envelope generator two affects both the amplifier as well as the filter cutoff. To dedicate the envelope generator two to the filter’s cutoff, simply patch envelope generator 1 to the initial gain parameter of the voltage controlled amplifier, VCA. This will decouple envelope 2 from the amplifier.

Envelope 1 now controls the amplifier, envelope 2 the filter cutoff only. To make the above behaviour audible, set the lowpass filter’s cutoff to about 50% and the EG2/Ext value (which basically means envelope amount) to about 80%.

Set the attack and decay times of envelope 2 to about 50% and listen to the output. The filter will open starting at about 50%, open completely and fall back to 50% during the decay stage. Feels familiar with me.

Remember the filter’s cutoff is set to 50%. Play a couple of short notes while raising the sustain level. Closely listen to the initial level of the filter at each note. It will fall below the cutoff set to 50% the more you raise the sustain level. This means to achieve the common behaviour of the sustain stage, adjusting it also requires adjusting the filter’s cutoff setting. At the same time, the decay will decrease, similar to other envelope designs.

I have no clue whether I got all the details right, but the above is what I think I understood so far. In case you find the behaviour annoying, leave envelope 2 alone and use the Kronos’ envelope generators 3 and 4 to control the filters.

The Access Virus is a very flexible analogue modeling synthesizer. Besides its oscillators, the two filters contribute to its premium audio qualities.

General

The two filters can be used in two serial modes, a parallel mode, and a split mode. Filter 1 can be used in both 12 and 24 dB modes. It also provides filter saturation or analogue modeling types.

A depiction of the filter modes (Serial 4, Serial 6, Parallel, Split) can be found here.

Since its early incarnations, the Virus provides an (in)famous parameter called »Filter Balance«. At a first glance it is difficult to understand what it does exactly, depending on the abovementioned modes. The manual only sheds little light on what it does exactly. I hope the following description helps to unveil its potential.

Filter Balance in Split Mode

• Oscillator 1 (plus the sub oscillator) feeds Filter 1 which is connected to the left audio output.
• Oscillator 2 (plus 3) feeds Filter 2 which is connected to the right audio output.
• Filter Balance controls the balance between the two filters (respectively outputs).
• In case you want to hear either signal on both speakers, set Pan Spread to 0% in the program edit menu.

Filter Balance in Parallel Mode

• The output of the Mixer section feeds the inputs of either filter.
• Filter Balance acts as a mixer of the two filter signals (Filter 1 only, both, Filter 2 only).

Filter Balance in Serial modes

• At the leftmost position of the Filter Balance knob, the Oscillators as routed through Filter 1 are audible only.
• At the rightmost position of the Filter Balance knob, the Oscillators as routed through Filter 2 are audible only.
• At the center position of the Filter Balance knob, the Oscillators are routed through Filter 1 and then through Filter 2. In case Filter 1 is set to a lowpass filter with a low cutoff setting and Filter 2 is set to a highpass filter with a relatively high cutoff setting, chances are given that almost no signal is remaining at the output of Filter 2.

It took me a while to understand the latter behaviour, since I thought in terms of simple analogue circuits respectively the routing of the filters as found in the Korg Z1. The actual behaviour of the Balance knob is more complex than just being a simple balance control. The way it is implemented provides a very musical approach, though. Even more when taking into account that the parameter is controllable via the modulation matrix, e.g. using an LFO.

I try to play the Wavedrum frequently. I mainly use the finger tips for playing rather than the palm (or even sticks). Unfortunately I did not pay attention to my finger nails, which scratched the original head quite heavily.

As a consequence, I needed to replace the head. As advertised by Korg, I’ve chosen the Remo Ambassador Fiberskyn3 10“ (model FA-0510-00). Replacement is simple. Just remove the 5 screws, turn the rim to the right (gently, so that the cable between the rim and the body does not get damaged), replace the head, put the rim in place and insert the five screws. The manual describes how to tighten them and how to calibrate the sensors.

While calibrating the rim sensitivity, one may be tempted to set the low value to 0 instead of something like 7. This leads to some hiss coming out of the Wavedrum though.

The next couple of days will show whether the Remo is more resistent than the original head :) .