Korg DSS-1 Oscillator Wave Comparisons

I was recently inspired to start creating my own Oscillator Multisounds by sampling some oscillators from Ableton’s Operator as well as some samples from Kontakt’s “vintage synth oscillators” like the Curtis SEM, Android and Oberheim.

This is a very basic, un-scientific example of some of the Korg DSS-1’s single cycle “oscillators”. It is a comparison of the internally created oscillators versus samples of oscillators.

What I noticed right away is that the internally created samples used one sample an octave above the lowest note, and stretched it downward to the lowest octave. No good! The DSS-1 uses sample rate transposition to change notes, meaning that to pitch a note one octave below the original sample it merely plays it back at half of the original sample rate. So your 32kHz sample becomes a 16kHz sample when played an octave lower! This was acceptable at first, but I had to get some nicer bass notes. Also, when scrutinizing the internally created sounds, I realized there were only 8 samples (Sounds) and the top-most sample was only 4 samples long!!! The internally created Multisounds are only 1020 samples total, whereas my lowest note sample alone is 1471 for one cycle! My Multisounds consist of 10-12 Sounds and are roughly 5000 samples total. At least my sampled top note is 64 samples in length!

The oscillator samples for this demo were sampled into the DSS-1 as loud as they could be without clipping. The best sounding ones are the ones from Ableton which were sampled at 48kHz into the DSS-1. In my “infinite wisdom” I decided that it would be good to sample other oscillators at 32kHz (like the Oberheim and Curtis SEM). I mapped original sample to the top note an let the DSS-1 down-sample to fill in the notes below. The reason for this is that I wanted to compensate for the fact that the DSS-1 does not have portamento and I wanted to be able to do octave pitch bends leading into notes. The DSS-1 can only play a maximum sample rate of 64kHz, so a 32kHz sample can be bent up and octave (to 64kHz), but a 48kHz sample cannot go up a whole octave. Hence the 32kHz sample rate I chose.

Truthfully I think that I should have sampled them all at 48kHz. In the end I was attempting to sample various oscillators from classic synths so I could have a cornucopia of synths at my disposal, but I will go on record as saying that most oscillators shapes sound roughly the same. So my idea to have a Moog Saw, Oberheim Saw, Android Saw, Juno 60 Saw and all the classics is probably just over-achieving and unnecessary.

This demo is just recordings of the raw, unfiltered oscillators. I did not adjust relative levels, because these are the levels that came out of the keyboard.

Strangely enough, I actually do prefer the internally drawn Pulse waveform. When I analyzed the waveform in the DSS-1, it shows that half of the wave is at full velocity positive and half is at full velocity negative. It is a mathematically perfect square wave. When comparing it against the Ableton Operator Square D, there isn’t much of a sound difference. Check out my DSS-1 tips and techniques where I describe how to create an 8 sample long “mathematically” perfect Square or Pulse single cycle Multisound.

The order of samples appearing in the demo is:

SAWS:
1. Internally created (harmonic synthesis mode)
2. Saw sampled from Operator at 48kHz
3. Saw sampled from Oberheim sample at 48kHz

SQUARES:
1. Internally created (harmonic synthesis mode)
2. Square D sampled from Operator at 48kHz
3. Square sampled from Android sample at 32kHz

PULSE:
1. Internally created (draw waveform mode/factory disk)
2. Pulse sampled from Oberheim sample at 32kHz
3. Pulse sampled from Curtis SEM sample at 32kHz

Advertisements

2 thoughts on “Korg DSS-1 Oscillator Wave Comparisons

  1. Harmonic Mode doesn´t generate a multi sample, that´s why it sounds bad in the low registers… the drawing waves, instead, generate 8 waveforms across the keyboard, and to me they sound great.

    • Thanks for your interest. The Harmonic Synthesis mode does produce a Multisound. It makes 8 sounds at different pitches and assembles them into a Multisound 1020 samples long, just like draw mode. Try using the Harmonic Synthesis mode, then editing the internal sound. You will be presented with an option to choose one of 8 sounds, all of which are the same length and pitch as what you get when you hand draw waveforms.

      I think the reason that the internally created waveforms don’t sound as good is that the value of samples does not ever go to the maximum. For instance, a mathematically perfect square wave should be maximum value (+2048) for half the time, then maximum negative value (-2047) the other half. When you use Harmonic synthesis, the resultant wave is hardly that. By using the “view sample data” mode of Sample Edit, you can literally “see” the sample node positions. The loudest velocity harmonic synthesis creates is in the 1750 range. It doesn’t use the full scale, whereas hand drawn samples do.

      Also, What is interesting is that even a 2 sample long square wave can be stretched down the whole keyboard and sound fine. That is because it can adhere to the above example, namely half the time it is maximum positive velocity and half the time it is maximum negative velocity. There is no gradation, so the square wave sounds fine. So I agree that hand drawn square waves sound better than harmonically synthesized square waves. Other more complex shapes need more sample data to accurately recreate the shape.

      I think the lower octave being stretched by internally created waves (harmonic synthesis or hand drawn) is a bummer, so sampling a clean oscillator can do wonders. Having a 48kHz sample instead of a pitch shifted 32kHz sample which becomes a 16kHz sample on the lowest note really makes a difference to my ear.

      Thanks for commenting!
      Nick

Reviews and Comments:

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s