Ramp-up sawtooth oscillator?
pitchblender
Glasgow, ScotlandPosts: 29
Hello all, I was just trying to emulate a Roland SH-101 sound after using an S-1 to create a preset and then I decided to recreate it using the Deluge from scratch (rather than just sampling the S-1 audio) as I'd like to learn more about sound design and the architecture of the 101 and how its physical layout relates to the tiny S-1's compromised controls.
Whilst doing this I was surprised to see that there's no ramp-up sawtooth option on the Deluge's basic waveforms list. Am I missing something? Can I invert the waveform at all? Would I have to use a single waveform sample as another potential workaround?
Seems like a simple oversight, but some of my favourite sounds have been from ramp-up sawtooth oscillators (Perfourmer, for instance) and I just thought I'd mention it here and find out what other folk think.
Cheers 
Comments
from my brief googling, apparently the harmonics of any inverted wave are identical to the non-inverted wave so there wouldn't be any audible difference between a ramp-up and ramp-down sawtooth oscillator. you can resample and reverse playing a sawtooth oscillator note and compare them, they sound the same (minus any difference in the envelope).
however, if you are talking about using a sawtooth for an LFO you can achieve a different direction. you would patch a parameter to LFO and go -50 instead of +50 (eg. filter -> lfo1 where the LFO1 waveform is set to SAW) a patch value of 50 will make the filter ramp up, a value of -50 will make it ramp down.
if you are noticing an audible difference between a ramp-up and a ramp-down sawtooths for a oscillator's waveform then it's because it's an analog device and there are slight imperfections occurring when switching the polarity of the waveform. but yes, a single cycle waveform can achieve what you'd like
Thanks for that @reza - good info cheers. After looking it up I see what you mean, although some folk seem to hear a difference between oscillator ramp-up/down waveforms with identical signal paths...
Plus some folk do mention that having both types on two oscillators with identical signal paths can invoke some interesting interference patterns, especially with analogue (or VA) synths, and when tweaked.
All very interesting so I guess I can experiment with single-cycle waveform samples.. just realised I can do this with a single preset on the deluge using the two sample slots - another rabbit hole discovered on this amazing device!