Vintage Oscillators

    The access virus has the most flexible filters around, you can get the most vintage approximations that any synth can achieve, but what about the oscillators?


    Wouldn’t it be great to have the punchy in-your-face waveforms from the past? You could truly Imitate your favorite synth from yesteryear, imagine the possibilities of putting these waves through the sound palette of the Virus.


    Each instrument has radically different waveshapes, here are a few of the different tonalities out there.


    [Blocked Image: http://www.bobborries.com/Tutorials/VintageWaveforms.jpg]


    (Waveforms were sampled raw without the filter)


    Here’s a list of some of the best examples of vintage gear, each with it’s own strengths and weaknesses to help create new sounds that echoes from the past.


    Mini Moog: Hands down the best sounding waveforms with very high fidelity.
    Arp 2600: Gentle strength
    Oberhiem SEM: High class velvet
    Prophet 5: Very popular Curtis chip
    Yamaha CS-80: This made Blade Runner sing
    Jupiter 8: Smooth as butter
    Korg PS-3100: Very distinctive sound
    Juno 6: Precise and Modern
    Atai 2600: The beginning of digital


    Real analog components can go out of tune over the years that significantly alters the wave shapes produced. An extra parameter that simulates out-of-calibration characteristics, such as transition artifacts on a triangle waves, sawtooth offsets and improper sine bias trims would be nice.

    Bravo. That is very interesting. So is there a way to change a falling sawtooth oscillator into a rising sawtooth on the Virus? Besides that point, you can combined a sine as your 2nd ocscillator to get rounder saws for a more vintage sound.

    Very sneaky Access, you put quite a few vintage oscillators in the wavetables, being new to the Virus, Iv'e been looking at the waveforms in the wavetables and Octavius is a MiniMoog Sawtooth in 6 separate octaves. I'll be posting a complete guide to the wavetables soon.

    Quote from bobborries

    Very sneaky Access, you put quite a few vintage oscillators in the wavetables, being new to the Virus, Iv'e been looking at the waveforms in the wavetables and Octavius is a MiniMoog Sawtooth in 6 separate octaves. I'll be posting a complete guide to the wavetables soon.

    I'll be looking forward to that! Still need to experiment more with the wavetables!

    The Octavius Wavetable is comprised of 6 different Vintage Sawtooths, each one an octave above the next. The wavetable fades very smoothly from the lowest octave all the way up to 2' octave. I thought all the wavetables were based on sine harmonics, but this is not true. When it's index is modulated by an LFO, you get the most amazing pad sounds.


    [Blocked Image: http://www.bobborries.com/Tutorials/OctaviusExample.jpg]


    Below is a Sonogram of the swept wavetable, left to right is time, at the bottom is low frequencies and as you make your way to the top the frequencies go higher and higher. Sawtooths contain all harmonics so you see all harmonic bands at the beginning, the dark black line at the bottom (C1) indicates fundamental frequency of the perceived note, the lines get thinner the higher you go up, and the upper harmonics get fainter. At C2 the line is darkest, same for the rest, C3,C4,C5 and finally C6.


    [Blocked Image: http://www.bobborries.com/Tutorials/OctaviusSonogram.jpg]


    Other vintage Oscillators to try are Eat Pulse, a crazy PWM type sound and Filtered Sqr, a filtered square wave (TR-606?), there's others and I'll have a detailed PDF examining all the wavetables, as well as the spectral waveshapes coming soon.

    First of all, it looks like you can emulate the minimoog/arp2600 square wave by superimposing a virus square wave over a virus triangle wave - just put one in each oscillator and mix (or maybe it is even possible to dial a "classic" oscillator between square and triangle). You might need to sync them and adjust the relative phase to get it perfect.


    Another thing i've found is that the analog/vintage modelling available in the charachter FX "ruins" the waveform well enough to produce a vintage sound. The question is, where is the character placed in the routing scheme of the virus. If it was placed even before the filters it would have had the desired effect. I hope that at least it is not placed after non-linear channel effects, such as distortion.

    Are you sure about all this? I don't want to be a damp squib but I had a little play with the Octavius wavetable last night.


    Firstly (obviously) the blend between waveforms is only as smooth as the interpolation knob determines.


    Secondly, in an A/B listening test, all octaves of the octavius, when pitched down to match, sounded nearly identical to the classic saw. If anything there was a minute touch less buzz in the octavius.


    Thirdly, a little time with the sMexoscope ( http://bram.smartelectronix.com/plugins.php?id=4 - it's free and very useful) showed that all the octavius wave shapes looked very similar to each other - not the wildly differing saw-ish shapes you'd expect from a collection of vintage synths. They also looked very similar to the Virus classic. The only difference seemed to be a slightly more exaggerated high frequency spike at the bottom corner of the classic waveform - which would explain the small amount of extra buzz.


    From this I conclude that the octavius is simply a Virus classic saw, resampled or re-engineered for the wavetable. The very slight difference I put down to the wavetable processing - or perhaps aliasing differences in the algorithm.


    I can see why they would do it as well - the octave blending feature gives some interesting sonic possibilities while sampling the classic oscillator keeps the character of the Virus.


    (On the other hand, if you ditch any requirement for a waveform to be identical to a particular classic synth there are plenty of interesting, punchy, and/or buzzy waveforms to be found buried away in the wavetables. So thank you for getting me playing with them. :) )


    Overall, it sounds like there's a thirst on the forum for vintage wave shapes. Adding a few wavetable sets containing the saw/square/triangle/sine/etc. waves of some of the synth classics from history would make a lot of people happy, I think. I could well be one of them.


    So +1 from me for classic synth oscillators in the wavetables.

    "Pulsechecker" (should've been called "Sawchecker"? :) ) is another predominantly sawtooth wavetable, to my ears.
    Besides the analog/vintage Character effects mentioned above for classic synth emulation, don't forget the AnaKey source in the mod matrix similar to the request in the first post.
    A good progressive use for wavetables with classic analog basic waveshapes is using them (not just square) with the Wavetable PWM oscillator mode, or the phase modulation wavetable parameter and Waveshaper saturation to produce more complex tones.
    Otherwise, personally I like the fact that the original intent of wavetables is to greatly expand the palette of available waveforms beyond just basic analog shapes. If we want to emulate vintage analog synths with wavetables then lets also be able to emulate classic digital synths (PPG/Waldorf Waves, DX7, D50).