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proxy
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Re: You want to buy a ____? Don't.

Post by proxy »

thelowerrhythm wrote: Mon Jun 28, 2021 7:06 pm I want to buy a Drezno and Lipsk, but only have a uh... I have a bunch of stuff.
something something bitcrusher + waveshaper....

get them!
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Re: You want to buy a ____? Don't.

Post by Kosmikos »

radiokoala wrote: Tue Jul 13, 2021 9:08 am S&H would sample voltage point of a signal currently present at S&H in, so if you trig it at the point it is fed inverted gate (-10.00 volts, for example) with whatever (like big red button you suggested), you'll have it output -10V, too (maybe not down to the millivolt, depending on its quality, but still). There is no way for it to output 10V when fed that kind of signal (inverted gate), the only possible two values would be 0 and 10 volts.

I guess that probably explains why that didn't work, but may be missing some extras of your patch. :)
Yeah that’s why I use a scale and offset to invert the signal before feeding it to itself. Maybe I’m over complicating it. The usual way I do this is to use a slow square clock/LFO into the S&H, but then I have to time my button press for the desired state. Or I use the switch on my Duatt to move from 0 to 5V with the knob at 12o’clock.

Sorry, I didn’t mean to hijack useful information with my experiments. I’m looking at switches at the moment, so these posts are of great interest to me.
I’d just need to make it work first (or not) so I can better explain.
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Re: You want to buy a ____? Don't.

Post by Wavtekt »

proxy wrote: Tue Jul 13, 2021 9:33 am
thelowerrhythm wrote: Mon Jun 28, 2021 7:06 pm I want to buy a Drezno and Lipsk, but only have a uh... I have a bunch of stuff.
something something bitcrusher + waveshaper....

get them!
Hendrick CV's ADC<->DAC in VCV Rack is basically Drezno and Lipsk. I am satisfied with that, since the signal is turned to digital at some point anyways. :cloud:
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Re: You want to buy a ____? Don't.

Post by radiokoala »

@Kosmikos
Yeah, no worries, it's all good: it's just that I'm sometimes too mind-boggled with things like voltage states and ORs, XORs, XNORs et al – remember typing a thousand-sentence patch few days ago and then being “whoa, wait, would that really do N if I offset X with Y?? :lol:” and really feeling that patch idea was falling apart as I was delving into my doubts. So it is is sometimes very troublesome to make sense of your own brain's signal path and thought processes, nevermind something written by an entirely different person and involving like, flip-flops, logic, and other rocket science utensils. (Flip-flops are relatively understandable though and hardly more complicated than professional-grade tennis shoes, but you get the idea. :D)
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Re: You want to buy a ____? Don't.

Post by Kosmikos »

Kosmikos wrote: Tue Jul 13, 2021 9:35 am
radiokoala wrote: Tue Jul 13, 2021 9:08 am S&H would sample voltage point of a signal currently present at S&H in, so if you trig it at the point it is fed inverted gate (-10.00 volts, for example) with whatever (like big red button you suggested), you'll have it output -10V, too (maybe not down to the millivolt, depending on its quality, but still). There is no way for it to output 10V when fed that kind of signal (inverted gate), the only possible two values would be 0 and 10 volts.

I guess that probably explains why that didn't work, but may be missing some extras of your patch. :)
Yeah that’s why I use a scale and offset to invert the signal before feeding it to itself. Maybe I’m over complicating it. The usual way I do this is to use a slow square clock/LFO into the S&H, but then I have to time my button press for the desired state. Or I use the switch on my Duatt to move from 0 to 5V with the knob at 12o’clock.

Sorry, I didn’t mean to hijack useful information with my experiments. I’m looking at switches at the moment, so these posts are of great interest to me.
I’d just need to make it work first (or not) so I can better explain.
Just to confirm my attempt to make a switch from a S&H didn’t work. :despair:

I tried this: Push button into S&H trigger, S&H out to attenuverter (x-1) and offset (+5V) to turn the 0V into +5V or the +5V into 0V, then back in into S&H. Starting with 0V in the S&H.

It seemed that the S&H state change doesn’t happen fast enough for the sampling to happen before the signal’s invert, so I always ended up with a half way voltage +2.5V after the first button press. I guess having a computer logic background doesn’t necessarily help in electronic where things don’t happen in a discretised way...

Inserting a slew in the loop did help a bit, but then the voltage droop was too big to make it a reliable switch.

At least I can now justify the purchase of a new module! :hyper:

For those who were wondering why I was talking of summer shoe fashion:
https://en.wikipedia.org/wiki/Flip-flop_(electronics)
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Re: You want to buy a ____? Don't.

Post by flashheart »

Excellent thread. I do take a bit of issue here though... :)
radiokoala wrote: Wed Jun 30, 2021 2:49 am Problem: You have been eyeing a diamond-encrusted limited edition ring modulator that would match your shiny airmaxes nicely. Unfortunately, all the money you could invest in this electronic fixture went towards a new pair of shoes that can't ring modulate or process audio signals (only if by dampening the tiny speakers). You have some leftover VCAs you do not know what to do with aplenty, though.
Grab a patch cable and another patch cable. Take a bipolar periodic LFO or oscillator wave you want to be a modulator. This could be a sine (classic ring modulation style for you) or square, wavetable or honestly anything. Now, what we are going to patch this into a full-wave rectifier, its output to VCA CV. Congrats, we are up and going. You just got some nice ring modulator kind of action (actually not just similar-sounding or ballpark-imitating but precisely the same as you would have with a dedicated module).
I'm 99% sure this isn't the case, ring modulation is NOT the same as FW rectification.
Anyway. Here's my version.

Turn a VCA in a 4 quadrant multiplier (or bipolar VCA/ring modulator).
Offset your modulator as above so the VCA is modulated from zero to full level. Then subtract 1/2 the carrier (ie. signal you're modulating) from this. When the VCA is full level the carrier is +1/2 level, when it's at zero it's -1/2 level. Ideally you need to boost this by a factor of 2 to maintain the same level. Which brings me too...
Boost signals with a mixer
We often forget mixers are SUMMERS. I've used a dual unity gain mixer to boost my iPhone's signal to modular level. Simply mult the source to more than one mixer input and the gain goes up by how many times you mult it. Using a dual 3 in mixer gives up to 9x gain if you're clever :).
like all these things if you need that specific thing a LOT it makes sense to buy a dedicated module, but if not...
I'm not buying a maths though, not my idea of fun...
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Re: You want to buy a ____? Don't.

Post by radiokoala »

Yeah, I seem to have oversold the efficacy of that technique – what I was describing there would be AMPLITUDE not ring modulation indeed. I should have left it at “similar-sounding” and not “precisely the same”, which is bold overstatement. :) So thank you for that correction.

There is also a way of getting 100% adequate rm in that example by adding in a comparator, inverter and a pair of VCAs. You will need to compare modulator signal with 0V (and hysteresis set at zero volt too) so that a gate is produced for the whole duration of the sine at phases 180-360° (negative voltage). Then send inverted carrier signal to VCA controlled by CMP GATE OUT and non-inverted to another one and INV CMP GATE to VCA CV In (with Bias set Full CW in case of this one). Mix the two.

I'm not sure about your method, though, flashheart – how exactly would scaling and amplifying the signal would flip it in and out of phase as required for rm? To be sure that I understand you right, how exactly would you subtract ½ the carrier: what module doing what?

I just woke up if anything. Thanks for sharing some more tricks! :coffee:
Last edited by radiokoala on Thu Jul 15, 2021 1:58 am, edited 1 time in total.
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Re: You want to buy a ____? Don't.

Post by radiokoala »

LOL, it's funny: I had just translated your post to Russian and then I found out what you meant. I did not notice “subtract the signal... from this” – this “from this” part I just skipped, and translating made me catch it. Meaning that a signal is subtracted from the modulator and not itself as I first assumed. Makes sense now!

Thank you for correcting.

:spin:
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Re: You want to buy a ____? Don't.

Post by etckla »

For a DIY ring mod I tend to patch 2 copies of the carrier (one inverted) to either side of a 134-2 crossfader, and then patch the modulator to the CV in.

There are a few recipes for patching a crossfader from VCAs, which you could probably use to further deconstruct this.
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Re: You want to buy a ____? Don't.

Post by radiokoala »

Also a good way to do it, perhaps simplest / the least complicated and easiest to patch of them all. :)

“Crossfader without crossfader” — on Page 4 here, too. Patching it all up, though, without having one, would instantly take this out of “simplest-to-patch” (and requiring least modules) zone, though, and would take about same number of steps as my (rect+inv+2×vca) or flashheart's methods.

But really cool and elegant.
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Re: You want to buy a ____? Don't.

Post by flashheart »

radiokoala wrote: Thu Jul 15, 2021 12:44 am Yeah, I seem to have oversold the efficacy of that technique – what I was describing there would be AMPLITUDE not ring modulation indeed. I should have left it at “similar-sounding” and not “precisely the same”, which is bold overstatement. :) So thank you for that correction.

There is also a way of getting 100% adequate rm in that example by adding in a comparator, inverter and a pair of VCAs. You will need to compare modulator signal with 0V (and hysteresis set at zero volt too) so that a gate is produced for the whole duration of the sine at phases 180-360° (negative voltage). Then send inverted carrier signal to VCA controlled by CMP GATE OUT and non-inverted to a other one and INV CMP GATE to VCA CV In. Mix the two.

I'm not sure about your method, though, flashheart – how exactly would scaling and amplifying the signal would flip it in and out of phase as required for rm? To be sure that I understand you right, how exactly would you subtract ½ the carrier: what module doing what?

I just woke up if anything. Thanks for sharing some more tricks! :coffee:
With the VCA at full level, when you subtract 1/2 the original you end up with 1/2 the original, when the VCA out is at zero if you subtract 1/2 the original (from nothing) you get the inverted original at 1/2 level. Remember subtraction of B from A is the same as A plus the invert of B. I'd probably combine the 2 with a bipolar mixer. 1 channel of a 3 x MIA would do it: VCA out at 1 input, original at the other with the pot set at -1/2. You could use a 2nd channel to double the gain :). Alternatively double the gain of the original, feed it to your VCA, then subtract ths original, this could be done using both channels of a dual unity mixer.
I'm not buying a maths though, not my idea of fun...
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Re: You want to buy a ____? Don't.

Post by flashheart »

etckla wrote: Thu Jul 15, 2021 1:09 am For a DIY ring mod I tend to patch 2 copies of the carrier (one inverted) to either side of a 134-2 crossfader, and then patch the modulator to the CV in.

There are a few recipes for patching a crossfader from VCAs, which you could probably use to further deconstruct this.
That works :)
From that thread:
Stereotactixxx wrote: Tue Aug 04, 2015 3:26 am You can also patch up a cross-fader using only one VCA.
Let channel #1 run through the VCA.
Let channel #2 be the dry signal plus the inverted (i.e. minus) channel #1.
I'm not buying a maths though, not my idea of fun...
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Re: You want to buy a ____? Don't.

Post by radiokoala »

Yeah, WMD Triple Bipolar VCA should also work nicely for that, conveniently also with a mix out. And maths, of course, when speaking subtraction and maths, it's like what things are supposed to be (peanut butter and jelly kind of match-up), so that is there too, even if not your idea of fun (as your signature says :roll:) – @flashheart.

These things do get confusing sometimes without graphs and like, so additional explanation is always helpful. Trying to visualize a wave as it is rectified and then summed with an inverted copy of another and what's going to happen as you multiply the two is no one-sec calculation and can cause overload of sort. It's like (n-(m*0,5))*m, calculate the value, repeat 10 times and try drawing the full picture in your head only. :russian:

Heh.
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Re: You want to buy a ____? Don't.

Post by etckla »

I just bought a 138m matrix mixer and now I want a scanner ala Verbos Scan & Pan :doh:
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Re: You want to buy a ____? Don't.

Post by docile fossil »

i haven’t been wiggling for long enough, but i recognize a golden thread from a country mile. 🏆
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Re: You want to buy a ____? Don't.

Post by radiokoala »

Haha, thanks, Mr. I Make Pedals Levitate! 🙃

I'll post a few more modular baroque-opportune tips for different flavors of polyphonic (as if there are any others!) counterpoint and melodic embellishments soon. Not as soon as today, exactly, but as soon as maybe tomorrow.

In fact, you curious minds out there can try and think up the way of obtaining ghost notes out of only 1 CV/Gate track (and 2 VCOs). They are one semitone or full tone lower and sound slightly before the primary notes making up the melody. Like BBC (ghosts) prior to CCC#, appearing all in order of B-C-B-C—C-C#.

PS. “What kind of a hellish quiz is this?” © QI.

😁😁
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Re: You want to buy a ____? Don't.

Post by Kosmikos »

Your quiz hurts my brain, now I really want to buy a Metropolix... :hihi:
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Re: You want to buy a ____? Don't.

Post by toppobrillo »

you want to buy a buttringer module? don't.
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Re: You want to buy a ____? Don't.

Post by Aaronautical001 »

Great thread! Can you do a pingable envelope generator?
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Re: You want to buy a ____? Don't.

Post by radiokoala »

Aaronautical001 wrote: Thu Jul 29, 2021 3:06 am Great thread! Can you do a pingable envelope generator?
Thanks!

If only by triggering an envelope with a clock generator, optionally patched to a clock div/mult inbetween – it's basically all there is to it. Of course, there are also all kinds of shapes and CV over multiplication/division factors – these are not easily found elsewhere, you'll need to look at LFOs with PLL or similar tempo-sync functionality like Mutable Tides or Ginko Synthese TTLFO, but at its most simplest, what you'd call “pingable envelope” is a clock + EG.

I think you already know that, six years on Muff's and all, so sorry I can't be more helpful with this. There are some flexible, multi-shape, and highly functional EGs like 4ms PEG, Modcan Quad Envelope (and Quad LFO) and Xaoc Zadar that make for a truly worthwhile investment.

I built my PEG from a kit, perhaps the best cost/value ratio of all. Make Noise Function + a clock could also be a mini-PEG in its own right, esp with rise and fall CV, similar to modulating Skew and Shape on one.
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Re: You want to buy a ____? Don't.

Post by helix »

Yeah i've always been a little confused about the term "pingable" envelope generator. Its a trigger input, that is capable of generating a clock signal after two or more "pings" and dividing it, or just using as a normal trigger. Easily done elsewhere. If you send the envelope shape into an adjustable linear/exponential vca etc, you can change the shape of the curve. Maybe not as much as the PEG does however. You could also mix two "pinged" envelopes/one shot lfos to create a new shape. Or wavefold it. Or send through a resonant filter or waveshaper/distortion/bitcrush etc.
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Re: You want to buy a ____? Don't.

Post by Aaronautical001 »

radiokoala wrote: Thu Jul 29, 2021 7:01 am
Aaronautical001 wrote: Thu Jul 29, 2021 3:06 am Great thread! Can you do a pingable envelope generator?
Thanks!

If only by triggering an envelope with a clock generator, optionally patched to a clock div/mult inbetween – it's basically all there is to it. Of course, there are also all kinds of shapes and CV over multiplication/division factors – these are not easily found elsewhere, you'll need to look at LFOs with PLL or similar tempo-sync functionality like Mutable Tides or Ginko Synthese TTLFO, but at its most simplest, what you'd call “pingable envelope” is a clock + EG.

I think you already know that, six years on Muff's and all, so sorry I can't be more helpful with this. There are some flexible, multi-shape, and highly functional EGs like 4ms PEG, Modcan Quad Envelope (and Quad LFO) and Xaoc Zadar that make for a truly worthwhile investment.

I built my PEG from a kit, perhaps the best cost/value ratio of all. Make Noise Function + a clock could also be a mini-PEG in its own right, esp with rise and fall CV, similar to modulating Skew and Shape on one.
Thanks! I probably wasn’t precise enough in my description: I was thinking envelope duration determined by duration between regular triggers (which I thought was the key feature of the 4ms PEG, but I don’t own one so I might be wrong). I was wondering whether a rectified output from Batumi through an analog logic (or for max is it?), but no control over envelope shape. Perhaps I should just get a PEG.

Anyway, great thread - thanks for starting it :tu:
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Re: You want to buy a ____? Don't.

Post by helix »

Ah yes of course the envelope length adjusts with the speed of the clock. That is cool, but if you're slowing down, the first envelope after changing speed will still be the length of the last one, meaning there will always be some latency when changing clock speeds no? So you're almost better off having a VC envelope for that...
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Re: You want to buy a ____? Don't.

Post by helix »

I found with my QPLFO it didn't really like the clock speed changing, it caused jumps and was never right, had that latency problem, rendering it almost useless, unless i changed the clock speed a step early, but then that wasn't useful for anything else
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Re: You want to buy a ____? Don't.

Post by radiokoala »

Yeah, quick after posting I was thinking you did really mean tempo-dependent rise & fall (a/d or a/r) stage durations, and here's a way of doing it no-PEG-involved.

“Time-Stretched” Envelopes
If you like to play around with different tempos while working on a song, but at the same time are fond of slow attack whooshes or long release echoing wind chimes, you'd be fast to notice these do not sound too right when you speed up from 60 to 240 bpm – too possible that amplitude envelope would not even reach its peak within a measure with its 1.5 sec Attack setting, and that would certainly make for a more swung-feeling groove. :drunkbanana:

Imagine you want to make these sounds more and more short as you increase your BPM — much like pitch shifting them up (an octave or whatever) would.

1. Use a VCO/LFO as the main clock setting the BPM and slave to it all of the associated CV and drum sequencers, tempo-synced random sources etc.
2. Use a DC Offset module as your Master Tempo controller. Patch an offset to the LFO and adjust rate (tempo of the project) with Offset Amount knob.
3. Trigger an envelope with that LFO, you'd need one with CV control over its Attack and Decay (or Rise and Fall, in other terminology, if you use a slope generator instead of usual ADSR).
4. Patch a DC Offset used to inverter and then to Attack and/or Decay CV. Likewise, you'd need to use a mult and send it to three destinations: V/Oct (or Exp fm) of LFO, Attack CV and Decay CV. With decay or attack set to (or close to) 0, you can safely skip that particular CV point, these sounds will always fade in or out about right at any BPMs, starting out right at the down- or upbeat that you wanted them while programming at the initial tempo.
5. Experiment with whole range of tempos and see if you are happy with the changing durations. If not, adjust the effect with an attenuator or amplifier inbetween inverted out and CV destinations.

Now, due to the instantaneous nature of this method changing up the envelope stage lengths at zero latency in parallel with BPM shift, it is more, engineeringly-speaking, perfect than what you'd get with usual tempo-synced LFOs and generators that need 2 triggers to adjust the stage lengths or elsewise compress the waves produced in time domain.

Bonus. :party: Use a CV sequencer output instead of DC Offset for automating Tempo changes!

Have fun :domodance: :cheesy: :smoke:
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