OP-X PRO-II - Virtual Oberheim Clone

A normal digital synth achieves polyphony by just digitally cloning the exact same algorithm into multiple voices which all are sounding exactly the same:

This may be convenient for synths that are concieved to deliver a digital kind of sound as known from romplers and workstations. But it is by no means convenient to emulate the lively and organic sound of early voltage controlled polyphonic synths. But why?

Having a look at the inside of one of those early polyphonic analogsynths which are famous for their full and lively sound you will notice that there are tons of electronics, with hundreds or even thousands of electronic parts. The reason for this is that each single voice in fact was a separate independent monosynth, sometimes even each one on a separate exchangeable voiceboard, controlled by a global interface. As an illustration a single voiceboard of an old OB-X:

Since electronic parts have individual tolerances those voices did never sound exactly the same by default. This was compensated by a lot of trimpots, which had to be adjusted for each voice individually to make them sound the same. This tuning procedure often was done by a service technician. But temperature drifts and aging again did detune the boards. So a re-tuning was needed from time to time. The pitch drift caused by temperature could be compensated with an autotune function, which was a standard feature in those early voltage controlled analog synths and had to be applied a while after switching on the device. So these early analog synths as well as never were absolutely in tune, each voice had a slightly different sound, since the fine settings of pitch, filter cutoff, envelope times, pulse width and portamento times never were exactly the same in each individual voice.

From the todays's point of view exactly this imperfectness with all those slight detunings did give those synths this beloved orgainic and lively sound. So to capture this soul a digital synth has to emulate all of this, including the separate voices with individual tolerances. Of course if would be great if the detunings could be easily controlled to have all options open. This is what OP-X PRO-II offers. Have a look at its structure diagram:

As you can see the engine structure of OP-X PRO-II is nearly the same as the one of a real voltage controlled polysynth. There's no digital voice cloning used to achieve polyphony. Each voice is a separate mono synth with completely independent signal path and slightly deviating sound by default. The detunings however can be globally controlled in every detail separatly for oscillators, filters, envelopes and portamento times.

In OP-X PRO-II you now even can continuously blend between the tuned mode and the custom detuning settings, calibrate the trimpots with a single mouse-click and involve or exclude any voices of choice in the rotating voice allocation algorithm.

Feature Clips

Listen to some clips that show the sonic result of this special engine. The clips below all have been done with the PROII_TESTPATCHES bank which is included in the free demo version of OP-X PRO-II.

Click on the speakers