Interfacing dRambo with Eurorack



  • @lala I didn’t know that either.

    I’ve just had a look and wow, that’s some serious shizzle.

    On another note.

    The power supply module for the filter can power two filters so guess what I’m doing now?

    Yup. 😁

  • I was half asleep when I read it, when I read cadmium I was awake again 😱

  • Well, this next bit will tickle you even more then.

    Further research has shown that cadmium can be found in chocolate.

    Obviously dark chocolate has more cadmium than milk chocolate. 😉

  • edited May 2023


    I certainly have no interest in consuming heavy metal because grandma used to do that. ;)

    this stuff is really pure poison ☠️

    if its not enough to kill you, it damages your cell structure , uuh bad, slow & creepy !!!

    think of radium or something , ugly ugly ugly ;)

    heavy metal intoxication is no joke ;)

    yum yum eat more cadmium ;)

  • @lala one thing I've learnt throughout the years, no one knows the time nor the hour.

    If we were to start listing all of the things that are currently in our ecosystem

    that is causing damage then we should rename this thread however I can keep the list very short.

    The one thing that causes the most damage in our World aren't the chemicals or whatever.

    It's humans.

  • edited May 2023

    Im a nurse, I used to be, I care about this shit.

    And I understand enough of it that it is save to say I sure dont want cadmium around me or eat it.

  • I hear you on that.

    Tonight of all nights I'm tired of hearing fearful things in regards to chemicals.

    One moment, "used to be " a nurse?

    I'll d.m. you.

  • oh, l just meant to say that I dont work at the hospital anymore. ^^

  • edited May 2023

    cadmium is really ugly poison. there is no way to remove it from your body at all.


    the more you eat of it over the years the more it grows in you. 😱 wow

  • On another note.

    Here’s my custom overlay for the Crave.

  • Can u print the full front plate, potentially with labels engraved?

    I’ve tried overlays in the past (some of them were supposed to be high quality) and I didn’t like them at all.

  • Yes, indeed we can do that. :)

    We’re currently seeing how fine we can print on wood veneer and engineering card with the laser cutter.

    Were also experimenting with different fonts and stuff.

    This overlay was a tester for colours. :)

  • Apparently the subharmonicon clone is on the way too... in red...

    the brute bundle, ugly edition :)

  • Yeah, I’ve seen them.

    The colours are certainly eye catching.

    The arguments on the forums are even more hilarious and it hasn’t even arrived yet.

    The Edge though is apparently shipping right now so I predict a lot more arguments, oh well. ;)

  • Talking about the Edge…

    Here’s my take on the DFam using dRambo and a Behringer X-Touch.

    It could easily be adapted for other midi controllers. :)

  • Update time.

    Though things have been rather quiet on this end of things I've been busy deep in the lab.

    I've given my rig a complete overhaul including rewiring everything down to the power supplies.

    I've moved my main (now vintage) outboard to one side for easier access

    and moved all playable equipment to be in front of me.

    I've re-arranged everything so that it could make room for

    my mini modular setup in my quest to fuse dRambo with Eurorack

    combined with my own personal exploration into modular and what it is.

    Like with all things huge change requires time for adjustment so

    I'll be going into further details as we go along until then here's how it currently looks.

  • Context.

    Sound shaping shizzle.

    Left hand side.

    iPhone 7 functioning as a mixer, CV controller and macro oscillatorith dRambo as the main host.

    Teenage Engineering M4 24db/oct low pass filter x 2

    Korg NTS-1

    Behringer 902 VCA x 2

    Michigan Synthworks 2HP2CV usb to CV adapter an adaptation of the Mutable Instruments CVPal.


    Komplete Audio 6 mkii sending out 2 CV signals,

    2 oscillators into the Teenage Engineering filters with main audio out via SPDIF

    Moog Werkstatt acting as a secondary oscillator going into a 3rd Teenage Engineering M4 filter.

    Behringer Crave using the "ASSIGN" function to control both filters on the Behringer and

    the T.E M4 filter that the Moog is going into.

    The easel directly in front has a SubZero SZ-MiIX08USB functioning as a summing mixer

    for the audio outs from the Komplete Audio 6 mkii, Behringer UMC-1820 and

    Art Multiverb Alpha S.E which is on the Auxiliary.

    The Zoom U-44 is in standalone mode acting as an A/D for the Komplete Audio 6 mkii

    giving an extra 2 inputs via SPDIF.

    On a side note, the D/A from the Komplete Audio 6 mkii is coming out

    from a Behringer SRC2496 into a dBx 266A compressor/gate.

    Finally on the right on side is a JoeMeek C2 option stereo compressor

    for subtle and not so subtle compressing.

    And finally on the right hand side is an Air 3 iPad with dRambo as the main sequencer and router

    and SoundCraft Notepad-5.

    The three controllers are 2 x Novation XL's and a LaunchPad X.

    dRambo is the main host and everything that can respond to midi and

    now CV signals (from side of things) is being done directly from within dRambo.

  • Before I continue I must say a huge thank you to the following.

    Novation U.K for repairing my LaunchControl XL with an awesome turn around.

    They removed all of the components in one of my XL's

    and replaced them with new ones in less than a week.

    Native Instruments for sending a replacement Komplete Audio 6 mkii

    free off charge when my original one died and finally

    Teenage Engineering for sending two replacement filters for the faulty one

    from my original pair hence why I now have three T.E filters, very happy about that.

    In regards to the Teenage Engineering Eurorack modules?

    For the price they are amazing, their filters are the most affordable around

    and it sounds much better than the filter on the Moog Werkstatt

    and you don't have to DIY.

    They track to 1V/Oct with ease so I now have three more oscillators.

    The only downside is that the power cable requires an adapter

    to fit standard Eurorack and they don't come with front panels

    however you can order the adapter and panels from OddVolt.

    They do come with standmounts so you could mount them on something

    I have one mounted on cardboard at the moment powered via usb.

    Yeah, cardboard.

    Yeah, I'm grinning.

  • Further thoughts...

    The Komplete Audio 6 mkii comes with CV capable audio outputs

    however it only outputs 2v+- which is enough for somethings but not enough for others.

    After roaming the internet for awhile I came across two main solutions for

    amplifying the K.A mkii outputs which are the the Maths module and

    the Doepfer A-183-3, the latter of which I'm going to be purchasing at some point in the future.

    I am currently using two Behringer 902 VCA's to amplify the K.A 6 mkii CV outputs

    and I've successfully got 4v +- which is more than enough for my purposes at the moment

    and it's given me a nice challenge more on that note later.

  • If you are sensitive to tuning like I am then I would advise getting a CV calibrator

    or something similar or you could use Tunathor from MiRack.

    Setting it up requires a little bit of thought however once done works a charm

    and because of Tunathor I don't need to get a Doepfer A-183-3 as yet.

    It does take some experimenting with to get enough range but it's thoroughly enjoyable once done,

    the reason why I'm mentioning this is because the K.A mk2 has only

    2v +- so to get 8 octaves one has to amplify the CV signal quite a bit.

    Now, here's the thing, I decided to get the Behringer 902's instead of the Doepfer A-183-3

    because I had read somewhere that it can amplify cv and audio signals similar

    to the A-183-3 so I took a chance and bought two especially as

    the price for two on was the same for the price of one Doepfer A-183-3.

    The Behringer 902's doesn't amplify 2v +- to 10v +- so heads up there

    unless someone knows different as I did have some issues with calibrating them.

    Nothing major, simply me experimenting with the output and exponential bias.

    However I did discover that one of them I doesn't have as much range as the other

    and I thought that's it I can't have 2 tuned self resonating filters.

    Luckly MiRack has Tunathor, a hardware calibration tool and so I'm now typing this

    waiting for it to do one last calibration before I drop it into my Eurorack synth mix template.

    Screenshots are on the way along with the calibration tool I put together.

  • Here's Tunathor wrapped up and good to go for the K.A mkii using the K.A mkii's usb 3+4 inputs/outputs.

    Change the inputs and outputs for your rig.

  • To use the calibration tool all one simply needs to is select the Audio input

    with the oscillator coming in and Tunathor will automatically detect it's pitch.

    To calibrate Tunathor press the "Calibrated" button shown in this screenshot

    Then go into MiRack and then press the "START CALIBRATION" button.

    Remember to turn down the channel volume otherwise you will be greeted with pitch sweeps.

    Wait until it goes up to 4200Hz and says "MAP IS AVAILABLE" or there abouts and then

    come out of MiRack and press the "Calibrated" again and that's it, playable CV.

    Do the same for whatever oscillator or self resonating filter that requires it.

  • edited July 2023

    After much trail and error I have now managed to sync

    the Behringer Crave's sequencer using the Michigan Synthworks 2HP2CV usb to midi adapter

    using two of the Gate outs and the CV out for "TEMPO", "PLAY/STOP" and "RESET".

    One thing to bear in mind, the external "RESET" input needs a long Gate signal not simply a pulse.

    Using dRambo's Gate+Velocity sequencer with a gate length of 150ms, a Midi CC Generator

    out via a Midi Out module set to midi channel 6 on the Michigan Synthworks solid sync is achieved.

    Changing the sequencer tempos from normal to double speed

    or half speed is now a CLIP of set notes in dRambo sending gate outs.

    The nice thing is that one can also double the tempo gate output from the 2HP2CV

    and send that on to the Korg NTS-1 which doesn't have much choice in regards to it's inbuilt Arpeggiator.

    The next thing is the modes of the CV Pal.

    Yup "RTM", sometimes it has to done.

  • For those who need to sequence the Behringer Crave using CV.

    As mentioned I'm using a Michigan Synthworks 2HP2CV which has 2 CV outputs and 2 Gate outputs.

    The CV outputs have a max of 4v and the Gate outputs have a max of 5v.

    I initially tried using the CV outs for the Reset and it was a bit hit and miss so

    I switched the Reset signal from the CV output to the Gate output which works much, much better

    when changing the Crave's patterns on the fly and wanting it to reset on the next phrase.

    Here's the thing I put together to do just that.

    CV 1 - Play/Stop

    Gate 1 - Reset

    Gate 2 - Tempo

    Adjust Gate length on the G+V sequencer and Offset to taste.

    Your mileage may vary.


    and link to the Mutable Instruments manual which the 2HP2CV is based on.

    On a side note I'm using controller messages instead of midi notes which gives

    more freedom in regards to modulating CV signals and sending Gate signals separately.

  • On a side note.

    Though the Moog Werkstatt has a nice sounding oscillator, it's inbuilt filter and VCA

    is pants however it does pair up nicely with dRambo's inbuilt filters.

    I'm sure some Moog purists will have an apoplectic fit when reading this

    but it's internal filter just doesn't do it for me.

    I'm so happy that it was my second synth and not my first.

    It doesn't squelch, it just sounds fizzy so on the physical side of things

    I'm looking into getting another VCA and external filter.

  • Okay back on topic.

    When I first got the Crave which I've mentioned earlier

    I immediately started building my own version in dRambo

    using dRambo's inbuilt modules, quite successfully actually.

    It doesn't sound identical to the Crave as that would require

    far more experience in coding and with modular

    than the experience I have had up until now however

    I did make a really powerful mono synth which can be turned

    into a polyphonic synth with ease.

    The three main challenges I faced were the sound of the filter,

    the behaviour of the VCA and the characteristics of the 3340 SEM oscillator.

    The oscillator in the Crave has internal bleed through and drift typical

    of analogue synths which for a lay person is difficult to replicate

    because the oscillator's in dRambo are simply solid sounding beasts.

    Bravo to Giku.

    Continuing on, the other thing that I discovered, as my journey to analogue

    synths and Eurorack per se started with dRambo, is that dRambo is theoretically and virtually perfect

    so you don't really need to think to in-depth about scaling, CV voltages or the sequencers losing sync,

    it just works so we're spoilt in that regards.

    The thing is through learning all of the modules in dRambo I discovered that even though

    the real filters and VCA's that I now have have their own quirks what I learnt from creating in

    dRambo translates very well into the real world much to my surprise.

    More to follow....

  • Update in regards to Tunathor.

    It does tune external oscillators quite nicely.

    If you're into drones and similar it's perfect however for fast runs it glides the notes so it's not much fun.

    Granted I am trying to scale up 2v +- to 4v +- and trying

    to play oscillators in tune which is a challenge in itself.

    I've got my eye on an Animodule Line amp which can amplify audio and CV signals x 3

    so when that lands I'll be trying this all over again without Tunathor

    other than that my low pass gates are on loan so when I get that back

    I'm going to see about turning my external filters into drum sounds

    and experimenting with the famous LPG sound.

    More to follow.

  • Ahhh yes the challenge that I had set for myself.

    One of the issues that can happen when scaling up voltages is that

    the CV signal stops being linear when it comes to the 1V/oct.

    It starts to curve and that curve isn't very nice when it comes to accurate pitch.

    Granted this is dependant upon how you're scaling the voltages,

    as mentioned earlier I tried using Tunathor however Tunathor has latency so the notes glide into place.

    I'm currently trying to create a Precision Adder, which is what one would use in physical Eurorack,

    using dRambo modules and this comes with it's own challenges.

    My math isn't the greatest however I'm almost there for 1 octave

    this means that over one octave I can adjust tuning per note by 0.005 +- in dRambo.

    I chose 0.005 +- because anything larger will send the signal into the stratosphere.

    I've yet to test this in the "real" world but I'm getting there so bear with me

    because now that I've done this the next part is for it to cover 10 octaves.

    Who said this stuff was easy. ;)

    On another note I've added a PayPal donation link to my dRambo/iOS YouTube playlist

    and I will be offering lessons for beginners to advanced dRambonauts

    and other stuff so get in touch if you're interested.

    More music videos are on the horizon now that I've reconfigured

    my music room for ease and performances.

    Here's my dRambo/iOS playlist.

    More news to follow. :)

  • Challenge done, well the first iteration that is.

    I’ve now realised that I’ve made a mistake.

    There are 13 layers per octave when there should only be 12 (Coltrane would’ve liked this)

    so there’s an overlap and because of that I’m going to have to go back into each layer

    and delete the 13th layer and adjust the scaling on the output to match other than that

    it’s almost perfectly linear taking into account that we cannot input really fine numbers

    which for most purposes isn’t necessary.

    So basically one can fine tune individual notes by almost semitone either way and that max-minimum value

    can simply be increased by changing the values in the relevant knobs.

    It doesn’t look like much but for someone who’s sensitive to tuning it makes the world of difference.

    Now to test it on the tuneable out of tune filters.


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