Interfacing dRambo with Eurorack



  • edited August 2023

    Ahh yes, what is it????

    It’s a precision adder/tuner or whatever I‘ve interpreted a Precision Adder is supposed to do.

    Basically it’s a tuner that covers 10 octaves.

    In regards to the tuning knobs? think like a guitarist.

    Back soon.

  • In total this is what it’s starting to sound like.

  • Hhmmmmmm.

    I’m having to rethink the Sequencer Play/Stop Reset patch for the Crave over CV so bear with me.

  • Further testing and it’s not dRambo at all.

    The Crave has a Reset issue.

    I’ve got access to another Crave so I’ll double check that at some point in the future.

  • Behringer Crave current workaround.

    Leaving it’s sequencer with Play/Stop permanently switched on via CV input seems to make sure

    that the Reset signal gets received properly and that the sequencer always starts on the one

    when syncing the Crave’s sequencer to dRambo via CV.

    Very important in regards to performances.

    This may be applicable for other systems that are using CV to trigger the Crave.

  • Not quite EuroRack however I must say that this landed today

    courtesy of Sigma from over on the Audiobus Forum.

    Stay tuned.

  • cool, best volca in my opinion, really great drum synth engine !

  • I thought I’d share this with you.

    My new module landed today, nothing that great but it’s really useful for boosting audio and cv voltages,

    something that’s going to come in handy for getting things in line so to speak especially

    when I need just that little bit extra and in this case it’s 3 x extra.

    However I had a stomach churning moment when I powered up my Eurorack utility rig and there was no sound.

    Thankfully a cable wasn’t in it’s right place so a couple of deep breaths later…

    There was sound and cv voltages are boosted over +-5 v so I can now have as much voltage as I need.

    Here’s the list for those interested in such things and why…

    Yorkmodular Optothing 3.5 which is a gritty LPG/VCA/Filter for experimenting with LPG’s obviously.

    Michigan Synthworks 2HP2CV which is a Midi to CV converter

    Behringer 902 VCA x 2 with multiple CV inputs (can be used as a cv voltage amplifier with some caveats)

    Animodule Line_Amp for boosting audio and CV voltages.

    As the Komplete Audio MK ii only has +-2 v per output it needs something like the Animodule

    to boost it’s voltage up to +- 5 v to get the full range of pitch cv for instance.

    Teenage Engineering -24db self oscillating low pass filters x2.

    All of this paired up with dRambo is going to make for some very interesting sounds.

    dRambo is going to be the macro oscillators by the way. ;)

    Back soon.

  • Quick update.

    Korg Volca Drum fully repaired with a drum stand design for it in progress.

    Here’s a rudimentary dRambo drum editor for it.

    The drum editor uses the available CC messages that the Volca Drum

    communicates with and it can also be used as a rather basic preset manager,

    to build upon the 16 memory slots that it already has, more on this later.

    Here’s some eye candy whilst I move on to the

    Precision Adder design mentioned earlier on in this thread.

    The original Precision Adder design version that I was going to release was way

    to clunky and not as intuitive as I would’ve liked so a major rethink had to be done.

    The tuning process is now much smoother without losing any of the original concept

    which was to find an easier way to tune external self resonating filters and synth oscillators

    note by note from C0 to C8 using only dRambo modules and a good tuner.


  • On route to a more stable low cost power supply I finally decided to make my own EuroRack Busboard using,

    strip board, 16 pin IDC headers, 24AVG wire and the end of a paper clip.

    My soldering skills left a lot to be desired however once mounted

    it looks pleasing enough to the eye and more importantly it has stabilised my modules.

    I was foolishly powering them in series not parallel, I was experiencing sag and fluctuations in the current.

    The busboard does need smoothing capacitors, a diode for polarity and for the visuals led’s

    however the damn thing works and cost less than a tenner not including the laptop power supply,

    combined with the +-12v dc power block it has cost me under £20 for a 3amp Eurorack power supply.

    On route I’ve discovered quite a few things.

    One of them being the output of an audio interface and if it’s linear or not.

    It’s just a thought, the thing is when tuning the oscillators both of the CV outputs

    that also serve as audio outputs from my KA mkii exhibit the same tuning problems

    at the same frequencies which got me thinking that possibly the frequency output of the KA mkii

    isn’t linear and that’s after using different voltages and scaling methods.

    Off the top of my head it’s low on the bottom end, dips around C4,

    peaks around C6 and then starts sharpen then taper off the further up it goes.

    Reminds me of a microphone frequency response curve.

    Plays havoc with the 1/V oct thingy.

    Something to bear in mind when using audio interfaces as CV outputs.

    DIY Eurorack busboard.

  • The final piece of the puzzle,

    a Beep Boop Electronics Line-Euro X10 Amp module

    which can boost audio and CV voltages by up to x10 and x20

    by changing the jumpers on the back of the module.

    Primarily used to boost line level up to Eurorack levels

    fortuitously it’s also dc coupled.

  • Quick update.

    Up until the arrival of the Line Euro x10 amp

    I was sending Pitch and Env CV from the Crave to the Werkstatt

    fun but limiting.

    Now I can play the Moog Werkstatt on it's own and combined with

    the Teenage Engineering POM filters it's a completely different sounding synth.

    Pitch and Envelope CV signals are being sent out from dRambo using the Komplete Audio 6 mkii,

    the signal from the KA mkii is amplified using the Line Euro x10 with

    Pitch going to the Moog Werkstatt and Envelope signal to the Behringer 902 VCA's.

    Another Pitch CV signal is also going to the T.E POM filter via the Animodule Line_Amp

    so I can have the filters in perfect or as perfect as can be, tune which makes for interesting resonances

    with the Werkstatt oscillator on input.

    So my current synth sounds are as follows;

    Behringer Crave, Moog Werkstatt, Teenage Engineer POM self resonating filter

    and last but not least a bass synth that I'm named Aurelius

    which I'm designing in dRambo with more on that later.

  • Update.

    My Expert Sleepers es-3 landed on Saturday.

    Current rig.

    Expert Sleepers is now two oscillators, four envelopes and two T.E filter sweeps.

    dRambo providing the oscillators, env’s, and the cv signals for the filters. ;)

  • and then this arrived.

    About to put together a dRambo editor for it.

  • dRambo+ExpertSleepers feat' the LPG's with KVB+Splat to Clat on ridem

  • Smooth! This all looks and sounds very good! I’m happy for you and more than a little jealous 😅

  • Thanks bro.🙏🏾

    It’s coming together really nicely. ;)

  • Korg volca beats dRambo editor is almost complete.

  • Aurelius performance synth.

    The Behringer Crave is the sequencer and dRambo is doing synthesis and Mastering.

  • I’ve started on the vocal processing chain.

  • The way you make it pierce through the drums, wow! Impressive

    Can I have a go? 😅

Sign In or Register to comment.