#772

the key is “normalling”: until you insert something into the inputs for channels 2 and 3, there will be a static DC offset present (+5V on one and +10V on the other as of the most recent Maths).

so the knob is dumb: it’s just attenuverting always, but the circuit designer was smart!

The Maths manual is actually a really great resource for your sorts of questions!

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#773

I found that having a visual representation for this kind of stuff is super helpful. This video has an oscilloscope throughout if you haven’t checked it out yet and is really thorough and straightforward.

#774

This is true. I am reading it.

I understand most of it, but for the channels for instance, it says “Normalized to a +10V [for channel 2, +5V for channel 3, like you say] reference for generation of voltage offsets.” which I sooort of understand as well, although not completely maybe the word “reference” in this context. But perhaps this is moving beyond the scope of forum posts and I should just read on in the manual.

#775

Thanks @ceedotgeedot! 20 chars

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#776

I think “reference” is just electrical-engineering speak here and can be ignored

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#777

This is tricky to understand at first because it is a hardware thing. I’ll say what I believe is likely happening at channel 2 (for example) is that maths is generating a voltage at all times at the beginning of the chain in channel 2 which then goes to the attenuverting knob - so if the knob is fully CW it is just spitting out the full value at the output; knob turned to 12 o’clock should almost cancel this voltage (attenuated to close to 0v); knob full CCW is the inverse of that voltage (so, negative the original voltage created internally). Now what happens when you plug a cable into the input of channel 2 is that the connection between that original internal voltage source is physically broken/disconnected inside the input jack (look up like “guitar pedal jack normalizations” or something to see a picture) so that instead of that internal voltage being sent to the attenuverter knob whatever you plugged into the input is sent to it.

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#778

Thanks for this. And I realized now that Intellijel Triatt and Quadratt functions the same way. It’s a thing. I just never got it before. Thank you for all the explanation. I still don’t understand precisely how this constant presence of either +5V or +10V normalization works, what it does to make the offsetting of the attenuates signal happen, but thanks to you grand folk I now know that I can use it!

Anyone know the history or origin of this function in modular synthesis? Or in synthesizers?

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#779

offsetting? or normalization? Normalization is actually a common practice in electrical engineering, and most jacks, if you got one to look at, are built with it in mind: you’ll see that by default there’s a physical connection between where the signal would otherwise flow and an ancillary little pin. inserting the jack physically breaks this connection by moving the little pin out of the way. Electronically it’s why your phone knows to stop the music when you unplug your headphones: there’s a little circuit there that tells your phone “something is plugged in”

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#780

I had to look up ancillary! First definition said: “connected with something, but less important than the main thing” (which sounds both very vague and very familiar).

I think I only thought normalization to mean that a signal is already routed under the hood to somewhere (the place it is normalled to), and that you can break this normalization by patching (if the thing is set up that way). I hadn’t heard it about the jacks like that, so that’s one more new thing learned today! Thanks @alanza.

But I was curious about the offset, and attenuation and offset modules as it’s own thing, in modular synths.

I see there’s also scaling. If you’ll all forgive me - what is meant by scaling?

#781

I think they’re all related concepts: if you think of CV as being like automation in a DAW, as, like, having electricity turn knobs so you don’t have to, then all of these tools are attempting to solve the problem of “I have the right shape, but it’s too big / too small / in the wrong place”. Whereas in a DAW you could just move the automation around until it worked right, in hardware you have to work a little harder

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#782

@alanza with the brilliantly simple explanations yet again. :slight_smile:

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#783

But I have to work harder in my DAW to make the automation there feel alive. On my modular it’s like a having secret gang of friendly electric ghosts (some of them very musical, some of them more in it for sheer timbral adventure) turning the knobs, and often knobs I didn’t even know I had.

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#784

So here’s something I spent a good half hour trying to patch up today and I just couldn’t quite crack it.

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Here’s a picture of my rack. I had a cool patch going where Rings was acting as a kick drum and I had Tides in the harmonic oscillator mode, with the sub signal going to to VCA, and the normal voice going through the Magneto and back to the VCA, and I tried to feed an envelope to the CV in to act as a sidechain on the effected signal, but I couldn’t get the timing right to suck on the beat and pulse between kicks. I know the sidechain is in there, I just need a little advice coaxing it out!

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#785

That should work. An obvious question, but did you use an inverted envelope from Maths? This is how I would do it.

So you want to set the level as a constant on the VCA using Level, hit the trigger input of Maths with a multed copy of the kick trigger into say, channel 1, and then turn the attentuator knob counterclockwise. Take the inverted envelope out of the channel 1 mixer output and into the CV input of the VCA.

Turn up the attentuator on the VCA to increase the amount of ducking; use the controls on Maths Channel 1 (you’ll want a slow attack) to sculpt the ducking.

Hope this helps.

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#786

Can I get some opinions on Befaco Rampage vs. Euro Serge DUSG? Thonk has the DUSG kit back in stock and I am mighty tempted…

#787

DUSG tracks 1v/o very well, but is more bare bones. Befaco uses less space and gives you the whole analog logic part plus a slightly more intuitive user interface - at least I prefer the sliders over the knobs and the knobs on the DUSG seem to be functioning weirdly backwards from what I would have expected (turning the rise knob clockwise makes the rise faster, i.e. if you’re thinking of it as an envelope, you turn the attack clockwise to make it shorter).

They’re both nice, though. Wouldn’t want to knock the DUSG, just tried to think of things one might want to know before making the decision.

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#788

I’ve also not used a DUSG, but the sliders on Rampage are very useful when manipulating a patch live. I’ve got slightly different caps on mine that work well for single / dual finger operation:

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The switches for rate (at the top) are also vey playable to introduce bursts of faster or slower cycles.

I was originally after a Maths, but bought it as I found a cheap one on ebay. Super happy with it.

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#789

I had a Rampage for a while – what I appreciated was the min/max/comparator outputs and the rising/falling gate outputs, and the manual trigger (why don’t more envelopes have manual triggers?)

But mine had slippery little knobs for the response curve, and I wasn’t into the sliders all that much. I also didn’t like how setting the speed to “slow” to get long enough decays meant losing any chance at a snappy attack. The output impedance was a little weird too, not driving passive LPGs for instance. I wound up getting a Function and a Contour instead (along with the Mini Slew I already had) and I think that’s my ideal setup.

I do sometimes regret not having one that will track 1V/OCT. Rampage could kind of do that over short ranges, better than the others I’ve tried. But it’s still fun to drive them from square waves or PLLs though, a habit I got into with the 0-Coast :slight_smile:

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#790

I’ve considered a DUSG. Heard it was a simpler build compared to Befacto. The 1 v/oct tracking would be the main draw for me, as I have a Maths.

#791

It’s a ridiculously easy build, since it’s mostly smd and the pcbs from randomsource come with all smd presoldered. You’re basically soldering in the knobs and jacks and put on the front panel.

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