Attenuverters and Inverters

Just started this thread to open discussion about Attenuverters, Inverters to open further discussion. How are you using these functions? Share your tricks!

I started a conversation on this because I would like to see a 1U Polarizer/Inverter - mainly driven by my use of Quadratt to take a unipolar signal and make it bipolar. When I think of the process that is being performed: simply dropping an incoming waveform by 5V - this simple function is costing me 14HP of 1U real estate.
As Damase says here:

“Waste” is a good word here.
This got me thinking about the larger concept around Attenuators and Attenuverters.

In a perfect world, where you have 1000HP or more, a bucket loads of cash (more than you already spent on your Eurocrack affliction) - every modulatable function would have an attenuverter. when I look at my case, most of the Intellijel and Mutable stuff has attenuverters on nearly everything (dubmix has 10, korgasmatron II: 4, Plaits: 3), and I have my Quadratt for doing voltage shifts and attenuation for CV inputs on modules that either don’t have, or don’t have the real estate to provide attenuverters.
Plaits may have 3 attenuverters for Timbre, FM and Morph - but I’d love to have them on Model and Harmonics too…

This kind of leads to the discussion of module design philosophy and the whole concept of modularity.
Some modulation sources include an output level (Pam’s NEW! Workout, Xaoc ZADAR) or none (ie. LFOs out of Tetrapad), and some destination modules that have modulation inputs without attenuverters (Mutable Marbles, Instruo Cs-L)- or lots (Make Noise QPAS and Mimeophon)! So you have duplication of control, or a complete lack of them.
Take for example, the Intellijel Dubmix. I’ve seen some mixers that are much smaller than Dubmix that provide 4 channels, an AUX bus, modulatable panning per channel, etc. with no attenuverters (Ie. Xaoc Praga) - but then you would need 4 Quadratt’s to control all of those CV ins. So two questions come into play - do I really need all these attenuverters? Where should the attenuversion be done - at the source, in a utility module, or at the Destination?

For my patches, I’m starting to go beyond the phase of “oh wow! I can modulate everything” to “how can I create complex sounds with lots of movement, that are subtle and change over time?”. And this is when I started realizing the deep importance of inversion and attenuation - and VCAs! I am really now starting to embrace the idea “You can never have enough VCAs” - only I’d extend that to “You can never have enough VCAs and Attenuverters”.

I just read a great patch example here:

Look at 1.7:
Take the output of an ASR or ADSR envelope and drive the CV of a VCA.
Now pass an LFO into the input of that VCA, and pass the output to the FM of a VCO, or the pan of a mixer, or some other modulatable parameter.
Really cool sonic animation here!
But without an attenuverter on that CV driving the VCA, the effects of the envelope are 100%.
With the Intellijel QuadVCA, I took it for granted that each channel has an attenuverter on the CV input.

1 Like

couldnt agree more. having attenuators on cv inputs of a module is not just a convenience to me. its becoming closer to requirement for my system. in the context of a larger system and how you want to patch on a daily basis, its an extreme workflow detriment to have lots of modules with essential functions that require external attenuation. I mean, imagine a 12u system of modules like this! unbearable for me… This is what initially drew me toward intellijel, with the exact module you mentioned the Dubmix… still to this day one of the only stereo mixers with attnuation for the panning Cv (how often do you CVpan without attenuation?.. answer is never)

people seem to brush it off as “you can just do it externally” and say this to me like i dont understand the concept. but trust me i know because im forced to do it very often, and it always changes the patch… ergonomically different, takes time/resources, takes extra thought process on something i shouldnt have to think much about… there is many reasons it pulls you out of the creative moment vs having the necessary attenuation ready to go every time for essential functions. I dont personally care if it goes unused much of the time or takes up extra space, i like having the tool available without having to think about it…

1 Like

You are so right - panning in a mix requires subtlety - move the sound off centre, and then 20-30% of modulation is perfect. I use my Dubmix as a submix, then pass the mix through stereo modules like QPAS, Mimeophon and Clouds, then out via Mixup.
I also have my two 7U cases set up to provide 6 outputs: Dubmix, Mixup, and a 1U Audio I/O - and then into Ableton via a UAD Apollo 8. This way I can have any combination of sources from eurorack going into multiple tracks in Live, and then add more effects like choruses, delays and reverb on a track by track basis.

Two other mixers with attenuated panning: Happy Nerding PanMix, and Roland/Malekko 530. I really like the PanMix - you can jumper the back and turn it into a 4 mono + 2 stereo input (via TRS 1/8") mixer, all with CV Pan - and even the stereo inputs can be panned! It’s just missing an AUX path. tempting…
The Roland mixer has 6 channels, each with CV pan and attenuators, but I don’t care the external I/O on it - I already have my Intellijel 1U modules and 7U performance case I/O for that.
So - I’ll stick with Dubmix until Intellijel makes something better.

Doing attenuation between modulator and destination should be an exception rather than the rule. I wish my Mutable Ripples had attenuverters on the Res and Freq inputs… same with all the inputs on Clouds.

The other problem I am encountering is that a lot of my mod sources are unipolar (Zadar, Pamela) - this is where a polarizer would come in handy!

there is a balance to be struck though ill add
i dont mean to say every single cv input must have attenuation… but a smart implementation which allows the performer to have the tools they need at their disposal, and still have extras available for more specific usage.

The essential functions being deemed by the designer as the artistic purpose of the instrument, to me when these functions force me to do extra patching it leads me to not wanting to use the module.

Rainmaker is a fantastic example of a smart implementation. some good examples other than intellijel i think are Verbos, and Addac. something like the bark filter provides attenuation on the cool scanning functions to maximize the artistic potential here, but still has VCAs available to modulate for every filter band. this gives limitless other options to patch yet the experience is maximized by actually leaving attenuation off of these VCAs as a sensible compromise of space and where to lead the performer.

ive had many modules that id call bad exmaples… they were brilliant in many ways but the interface decisions of how it is controlled and operated eventually made me not want to use them

Here is some further points on polar vs. bipolar modulation:
Task: Pan an audio signal from 10:00 to centre.

First scenario, using a unipolar source:

  • LFO is a sine wave going from 0V to 10V. plug the LFO into my mixer pan CV (with attenuators). I set the pan on my mixer to 10:00. Then I attenuate the LFO input so at 5V the signal is fully balanced.
    If I want the width of the pan to be wider, I need to turn the pan knob more left, and then increase the attenuator level. If I want the pan to go further left, I only need to move the pan knob more left.

Second scenario, using a bipolar source:

  • LFO is a sine wave going from -5V to 5V. plug the LFO into my mixer pan CV (with attenuators). I set the pan on my mixer to 11:00. Then I attenuate the LFO input so that the spread of the modulation goes from 10:00 to centre.
    If I want the width of the pan to be wider, I just need need to increase the attenuator level. If I want the pan image to be more left - I just turn the pan knob more left.

Same result… but using a unipolar signal is more intuitive to me. Less fiddling.