Making acid | 303 techniques

[scanner_darkly]

yeah x0x heart is what i’ve got, i’ve been using this system:

but tempted now to expand it, it really needs a delay, another filter and some modulation.

[audionerd]

haven’t found the time to put the code online yet but i used “Analysis of the µPD650C-133 CPU timing” for this sequencer and it turned out fun and very playable. editor runs on norns but can also upload the pattern to crow for standalone playback.

[audionerd]

Haven’t used one myself but also worth a look:

Stepper Acid - Eurorack Step Sequencer - Transistor Sounds Labs

[RABID]

@scanner_darkly

the actual waveforms apparently are not typical square/saw

those waveforms will help perfect
ya the square never sounded quite like a square to me, seeing the actual waveforms will help(think i might start from trying to get those as close as possible)… thanks again

[scanner_darkly]

very cool! are you using crow for CV outs?

[audionerd]

yeah i added crow support later. in the video its midi to malekko sync w/ cv/gate expander

[scanner_darkly]

how do you handle slides? overlapping midi notes?

[audionerd]

my sequencer doesn’t try to emulate the 303’s slide. i use the x0x heart, which has a slide input, so it just sends that a gate. it does emulate the 303’s timing and logic re how to send the slide signal.

[dianus]

I had the Copper Trace’s SEEK for a while, it’s great to use, and gorgeously built. It feels quite familiar to operate to the 303 itself, some added features like the evolve function which was subtle but nice to add some generative progression to the bassline. I had a euro XoXHeart too, it was DIY, not sure if it was the way I calibrated it, or built it but it never had a perfect 303 flavour.

Catalyst Time’s Arrow is what I originally wanted for my 303 acid skiff, but I could never get my hands on one.

[john-smith]

I’ve never used a 303, but I’ve been looking at the Cyclone Analogic TT-303. It’s an analogue clone at about the same price as the boutique TB-03, and it’s got an input to go through the filter which the Roland does not – could be fun!

[toneburst]

@audionerd

haven’t found the time to put the code online yet but i used “Analysis of the µPD650C-133 CPU timing” for this sequencer and it turned out fun and very playable. editor runs on norns but can also upload the pattern to crow for standalone playback.

Wow, that’s very cool! Hope you have time to put it online someday. I’d love to play with it.

Great work!

[toneburst]

I looked into this sequencer for bassline use, but I think it lacks per-note “slide”, doesn’t it?

[HateNames]

I use a tb-03 to sequence eurorack. I love it. It’s strange hearing acid style sequencing with something very not acid, like mutable rings for instance. I’ll try and find a clip to post.

[HateNames]

Now I regret selling rings

[scanner_darkly]

does anybody have any experience with x0x heart mods? it’d be particularly great to expand ranges for some of the parameters. there is some documentation on the rabid elephant site: https://rabidelephant.com/blogs/general/x0x-heart-modifications but no sound examples, so hard to say how much difference these mods make. [also a personal request - not being a DIY person these are not something i would attempt - if anybody would be interested in being hired to build a modded x0x heart please let me know!]

[RABID]

(made a small discovery about the oscillators given the link with oscilloscope pics @scanner_darkly posted awhile back - the sawtooth, being analog, looks curved as bandlimited sawtooths in the digital world do, so when you take two of them, offset in phase, and subtract them from each other, you get the square:

Roland probably did it by one single oscillator by introducing a delay to create second saw with phase-offset…
i guess i knew you could get a square subtracting saws before, but since the waves looked so different from what i’m used to seeing in the digital world, didn’t quite piece it together for the look of the analog ones.
so now i just need to study up on softening those curves/sharp-turns in the waveform better(then further scaling if needed to normalize within a more desirable range, followed by the filtering… baby steps )…
even though the waveforms looks different, i might look into this more to start with:
https://www.semanticscholar.org/paper/Synthesis-of-Quasi-Bandlimited-Analog-Waveforms-3%2F-Schoffhauzer/ee7aede98685275144487265045ad08ce90c2ed5
my mind gets curious about so many tangents, but sometimes answers get found there, too… we’ll see )

[scanner_darkly]

can’t seem to find anything about how the 303 square wave is generated specifically other than it’s “derived from the sawtooth waveform using a simple, single-transistor waveshaping circuit”. there is some interesting discussion here: https://www.kvraudio.com/forum/viewtopic.php?t=455469

i assume it would be easier to generate a square using a comparator, but then it won’t have that characteristic shape i guess? with your approach, the amount of delay has to be based on frequency, right?

on x0x heart you can mix square and saw, and when you do, pitch goes up an octave which might also provide a clue about the phase relationship between the saw and the square.

[Gregg]

Mi Super 6 doing some slow acid the other day

“http://hermetechmastering.com/Super6Acid.mp3”

[RABID]

@scanner_darkly

the amount of delay has to be based on frequency, right?

exactly(i should’ve called it a ‘variable-delay’ which would be varied according to the freq of the saw osc)… but reading that thread, waveshaping sounds much more likely, i’ll have to explore that first(personally, i don’t like the control-response of a variable-delay in a digital realm so i’d prefer to pursue that other possibility, anyways).

[def-bln]

I have a tt-303, and today I discovered that while in pattern write mode you can shift the sequence by holding function and pressing back or next. While in syncopation with a drum track, especially one with side-chaining, even single note offsets can completely change the groove.