Seeking assistance with automatic wavetable scanning function

Hi! So I'm kind of stuck here with something, was hoping someone might chime in/shed some light. I set up this little auto-scan deal for the wavetable oscillator, but it turns out it doesn't work quite as I'd hoped. Basically, I’m using counter modules driven by an LFO to move wavetable position up or down, by a very small increment at a given rate, for the duration that a respective momentary button is depressed. The hitch is that the wavetable position/value arrived at this way does not hold once a project is saved and reopened. Is there any way to keep track/memorize the value arrived at via this set-up? Or perhaps another way to achieve this same function? What I wish I had is something that records every change in value, then remembers and holds that final value, until the next time it is altered. But I don't think that's a thing. Anyway, any suggestions would be much appreciated! Thanks in advance.

Here's a link to the patchstorage page:


  • Try using the Automation Lanes.

    You can record the changes in values for almost any given modulation point.

  • I think sample and hold modules will actually hold their value on project or rack save. See if they could be incorporated into your patch.

  • Interesting question @mikelcoolj. And thanks for posting the patch so we can see what exactly the issue is.

    Saving the current values of modules is partly supported but my guess is that the counter module is reset when loading the project because that's more likely to be what people would expect: A time signal that starts at zero.

    I have no idea how to memorize an intermediate value, not even the S&H module supports it and I think the only solution would be to add an option to Counter and S&H to save the currently stored value with the project if enabled.

    @giku might consider adding this.

  • @rs2000 but S&H values are saved in project and rack. I just tested it.

  • This is good to know because I've been using automation points in CLIP's to save values.

  • Ah, I only saved the module preset and it didn't work.

  • Hey, thank you all for the replies, really appreciate it! The use of S/H module is showing definite promise. Currently I've got it retaining the value/position upon saving/reopening, though now having trouble with the reset, which requires a subsequent +/- input to return to zero, as well as the + and - counters not recalling their prior positions and therefore jumping to zero (I believe) instead of proceeding from the saved value. Fairly obvious, as I've only attached a S/H at the end of the chain and not tied to the respective counters—not terribly familiar with sample/hold, and at this point doing quite a bit of guesswork. I'll attach what I've rigged up since reading these replies, which just to reiterate, have been a great help! Thanks so much, and apologies for just sort of "winging it" out loud lol.

    Link: (same patchstorage page, updated file)

  • @mikelcoolj

    You're welcome.

    I'm also still winging it so I've learnt something new today.

    Thank you.

  • @gravitas no shame in that, right? Big part of why I find Drambo so engaging, just sort of learning as you go, trying different things, reading up, so on/forth. The more I get to know all the different modules, the more it feels like really anything is possible in Drambo (a bit of earnest shilling there)

  • Current status: I've got it retaining the final value, but despite the addition of S&H modules for the +/- counters, subsequent changes in value upon saving/reopening will trigger a return to zero and procession from there. Still can't figure out how to get the value to reset to zero, manually, successfully, either. Feeling a bit stumped.

    The feature that @rs2000 posited, an optional memory feature for counter module, would be awesome, specifically for storing incremental value shifts. I'm loving the new buttons module, with the momentary option, and I really want to weave that into things like wavetable position and such, as an alternate way of inputting permanent changes to values. But of course, if there's a way to do it with the existing modules, that's half the fun. Thanks!

  • @mikelcoolj It seems that all we need is retaining the current counter value when saving a project or saving a Counter preset, right?

  • @rs2000 I believe that would do the trick, yep

  • maybe get rid of counter module and do something like:

    feedback receive -> some modules to add and sub value from fb output -> S&H -> feedback send?

  • @clowm Hadn't considered using feedback send/receive, that's a good thought! Tried it out as you suggested and got it to work smoothly to maintain value for incremental changes, ie one tap at a time; though, without using the counter, I couldn't figure out how to drive it by LFO, ie to have it increase/decrease value continuously while the respective momentary button is depressed. I'll keep it at, though—another piece to the puzzle. Thank you!

  • I don't see your patch but the S&H module will certainly need regular triggering while increasing or decreasing.

  • @rs2000 Here's the one where I tried using feedback. I have an LFO attached to the gate of the S&H modules, but it only changes the value by one increment at a time. May have missed something obvious, my head's a little fuzzy at this point lol.

  • edited May 2022

    No prob.

    Set the Mini LFO to bipolar (unipolar won't safely trigger the S&H stages) and you might also want to increase the feedback delay to sth like 100ms and decrease the LFO speed a bit to get a more controllable behavior 😊

    That's a well done patch!

    I guess you have some experience with modulars?

  • @rs2000 That absolutely did the trick! Thanks so much. Good to know about bipolar vs uni for triggering gates, I'd wondered about that. And, is saw-down preferable to pulse, for that purpose? The little things I've never been quite sure about.

    Anyhow, and more to the point—it's working now! Granted, still trying to work out a reset function for the whole thing; with the counters, that aspect was straightforward—not quite sure, now. Maybe Reset Time could come into play? Thoughts, per usual, more than welcome. Really appreciate the help.

    Oh, and thank you for the kind words re: the patch! It's part of a broader synth that I'm retooling, a kind of workhorse 2-osc wavetable with all the basics, plus a couple bells and whistles (like this auto-scan deal here), packed in. I actually don't have any prior experience with modulars, hardware or soft, just Drambo. To this day the best $20/25 I've spent on anything synthesis/production-related—my wallet will forever be grateful lol

  • @mikelcoolj You're welcome!

    The waveform doesn't matter as long as it's crossing the zero line, even a Math => Scale & Offset module with a slightly negative offset would have done it.

    Reset is nothing else but feeding the S&H with a defined value (i.e. number) and giving it a trigger. Temporary feeding both S&Hs with that "zero signal" is probably easiest done using an X-Fader mixer module because it could be modulated by a Reset button for example.

    BTW, one trick I've found a while ago: Placing an FM Operator module behind the Wavetable module can help to take out the "harsh" and add some "beef" to the sometimes cold and sterile sounding wavetable output. Could be an interesting option to add to the buffet.

  • @rs2000 Was not aware that zero-crossing is the key to triggering gates—good to know! Now, re: reset, I've been trying to temporarily feed the S&H modules with a zero value using the number module to no avail—something I'm missing? I've tried both the x-fader and 1-n modules, attached to both the value and gate inputs of S&H.

    Could you elaborate on the FM Op trick you mentioned? Do you mean mixing the Operator signal in with the wavetable output, to sort of soften it with the sin wave? Thanks

  • Excuse me, I meant N-1 switch*

  • edited May 2022

    @mikelcoolj Yes, basically that.

    About the zeroing:

    Here's a simplified version of your patch that also has a zero function and the current value survives project save & restore:

  • @rs2000 Thank you so much, that solved it. Still fine-tuning some stuff concerning increment and rate of scanning, but generally speaking, it's fully functional! I'll link to the working project, in case anyone is curious. Hope you don't mind that I drew fairly heavily from your work there, @rs2000!

    By the way, should I change the thread header to say [SOLVED], as I've seen people do? Thanks again.

  • Thanks again to @bcrichards @gravitas @clowm, by the way! True group effort

  • You're welcome.

    By the way, I also started learning modular through dRambo.

  • @gravitas I have a feeling there are more of us out there! It’s just the right balance of accessible and open-ended, really hits a sweet spot

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