I built my synth for drones and generative ambient music but I have an acid techno itch that needs to be scratched. I was hoping to get some patch ideas from the community so that I could break away from repetition and maybe learn something new. I'm still relatively noob (started building in 2020). What are your favorite patches to generate acid bass lines? Would you add or ditch any modules from this rig?

ModularGrid Rack


Suggest you grab a wmd time warp before wmd goes away. The ability to pitch slew on demand with ease and full control will come in very useful for acid.


Thanks for this suggestion. I think that its definitely an element that I am missing. I had been looking at pitch shifters and precision adders but couldn't quite piece it together. I ordered one this morning. Such a shame about WMD. Hopefully they'll be back...


I think there are two sides to your question. The first is how to get the acid sound (aka the sounds design) how to create evolving melodies (specific patches/modules). I'm by no means an expert, I've also stared my full modular journey in 2020.

Of course the synth that introduced acid is the Roland TB-303. I don't have one myself so I cannot give you all the details about this. If you want an exact replication of this sound then there are some modules that are basically 303 eurorack clones like the Open Music Labs x0x heart (https://www.modulargrid.net/e/grayscale-x0x-heart-eurorack-module). If you want to build it out of a oscillator/VCA/filter/envelope combination, know that the main characteristic of the sound is the filter and its resonance, for the other parts like osc and envelope you can use whatever modules you prefer. There are plenty of filters that "scream" in the same way a 303 filter does.
The original 303 has a slide option as well. You can achieve this by adding slew to your pitch CV. You have dedicated modules for this in a small package, like the WMD Time Warp that nickgreenberg mentioned, but you could actieve the same thing with a gate/drum sequencer or something else that produces gates, an attenuator and a slew limiter. I believe you have everything in your rack to achieve this as well, but like mentioned it takes up a few modules vs. WMD's one-in-all solution.
Let me know if you want more detailed info on these above topics.

For evolving acid patterns/melodies, there are a million ways to achieve this. What I think you want is a pre-programmed or random set pattern to slowly change rhythm, notes or velocity over time. Everything that generates CV can be patched into a quantizer to generate pitch information in a specific musical scale. I've seen people use LFO's, multiple mixed LFO's, noise, envelopes, you name it.
What you might want to look into is called "Shift Register" or "Turing Machine". It has a list of random, generated or input voltages. This list is looped and moves (or shifts, hence the name shift register) with every clock input received, over and over. With knobs or CV input you can determine what the probability is the current voltage will stay the same. If its set to 100%, every voltage will stay the same, thus looping it. If it's set to 0%, the voltages are all random again. Divkid has a good video about the Music Thing Modular Turing Machine, which I think the most popular module in this category:

You can achieve similar results with the gear you already have I think. Some examples:
- I believe the Eloquencer has a few ways to throw randomization into pre-made patterns, you could look into that.
- Disting Mk4 has a Shift Register built-in as well as described above, F-6 Shift Register Random Quantized CVs (check the manual).
- Disting MK4 has a quantizer as well, which can be used to turn other CV sources into pitch information. As input you could use anything you want, such as:
- Create a complex envelope on XAOC Zadar, trigger (or loop it that's possible, don't know this module) it from somewhere. This is your looped melody. Patch other LFO's like the XAOC Batumi or Instro Ochd into a bunch of attenuators and use the attentuators' output to control multiple parameters on the Zadar. The more you turn the attenuators, the more you change the envelope aka your melody.
- You could go the other way around as well, so not Batumi modulating Zadar, but Zadar modulating Batumi. Use a mixer to mix all Batumi's LFO's (or patch the output of one LFO into anothers input).
- You could expand on this idea by not using attentuators to evolve the melody, but replace the attenuator with a VCA and use a gate as CV input to evolve the melody on specific steps with a gate/step sequencer.
- Pamela's New Workout has a random stepped voltage output type. In the same menu, you have an option to loop the output for a number of steps. This value can be CV controlled. Use something that creates an offset voltage (like the Befaco A+B*C with nothing patched in) to set the desired amount of looping steps. If you then briefly set the CV input back to 0V, the output starts randomnizing again, until it receives the offset voltage again. Sending it 0V and the offset voltage every few bars evolves the melody, the amount of evolvement can be controlled.

Good luck!


Thank you so much for typing all that out. I was looking at the Alan module as a turing machine option but I'm not sure what it would accomplish that PNW or the Winter Modular won't do. I'm going to read this like a dozen times, watch the links and then put it to practice. Thank you so much for your time!