CV External instrument problem

Hello, I'm new to dRambo and i want to use it only as sequencer for my ext gear.

I want to to sequence my DFAM using MOTU Ultralite mk5 DC coupled outs.

I already succesfully synced it and get gate to work but i have problem with getting CV pitch right.

Apart from pitch calibration, pitch seems to change with really slow glide. It doesn't change instantly.

Everything seems ok and i don't know where to look for solution.

Bonus question: what will be proper CV scalling for this setup? Once i will be done with glide i will try to calibrate it trying various values, but maybe someone has some tips.


  • It maybe possible that the outputs of the Motu aren’t changing voltage fast enough.

    Do you have another synth you can test for CV pitch?

    What is the maximum +- voltage that the Motu has on it’s outputs?

    I have a Komplete Audio mkii which was +-2 v dc on it’s outputs which gives about 4 octaves at 1/V.

    I’ve used a Behringer 902 to amplify the signal up to +-4 v dc which worked but has

    it’s draw backs as the Behringer 902 is a VCA and I experienced the similar thing to you which is the notes

    glide into place so I’m waiting for an Animodule Line Amp, which can boost two channels of CV, to arrive.

    Both the Maths module from Make Noise and Abacus by Behringer can scale up the voltage needed.

    The other thing you could get is a Doepfer A-183-3 which can amplifier a signal channel of CV.

    Basically take the input voltage and boost it up to +-5v dc.

  • edited September 28

    Funny that i was going insane for weeks with this and when i wrote this post i came with idea that i will open just drambo and setup it exactly the same as i had using dRambo in AUM with routing to motu.

    Without aum it works perfectly. I even found out that scale 1.315 is in tune.

    Somehow AUM interrupts the signal. Gotta double check everything, but no idea what causes this problem.

  • @peterwyst

    I’ve answered my own question the Ultralite mk5 has 8.5v on it’s outputs.

    With that amount of voltage you should get a wide range of octaves however

    at the very top and very bottom you may experience scaling issues

    still, it covers more than enough.

  • edited September 29

    Sounds like a very low cutoff high-pass filter messing with the signal in AUM. No idea. Can't confirm here.

    You can find out yourself by routing a very low frequency rectangle LFO signal from Drambo to AUM to Drambo with just an oscilloscope for monitoring the signal drift.

  • @rs2000

    I’ve just tried using the dRambo External CV Instrument in AUM.

    My envelope/gate outputs are on outputs 1+2 and pitch/LfO etc are on outputs 3+4.

    I cannot use the External CV Instrument directly as it can only select ext audio which is stereo.

    To be able to trigger both env and select pitch at the same time

    I have to create 2 instances of dRambo with the modules connected directly

    to the audio out from dRambo and routed to the necessary outputs in AUM.

    I could do dRambo multi out but I haven’t tried that yet.

    ps @peterwyst that Motu Ultralite mk5 looks really good so it’s ended up on my shopping list.

  • @peterwyst I’ve just had a play with dRambo in AUM.

    Are you using dRambo multi out when hosted in AUM?

  • yep, multi-out and added few multibus tracks from drambo in aum to route it to the outs of motu

  • Okay,... can you send me a project with dRambo

    configured for the way you have it in AUM.

    One output for Pitch and one for gate/envelope.

  • Excuse the thread clutter but is the Drambo mfx multibus working for anyone in AUM? It's only seeing the additional outputs on the regular Drambo(8outs) here but not if you place the multi out in the fx slots.

  • It doesn't have multi outs when being used as an effect in AUM

    and I've checked with other apps that have multi outs in the effects slot

    and neither do they.

  • miRack does though, but that's the only other app I have with multi fx out so hence I assumed that Drambo could do the same thing.

  • Ahh my apologies.

    dRambo doesn’t have multi outs as an effect it seems.

    I’ve just had a look at MiRack and I can see what you’re saying in regards to multi outs when used as an effect.

    I was looking in the wrong place for it as I haven’t ever needed to use it as such.

  • @giku it would be great to have Drambo as multi-in and multi-out fx similar to Mirack, it introduces lots of possibilities esp with punch in effects.

  • @peterwyst

    I’ve just discovered for myself what you’ve been saying in regards to CV Pitch gliding.

    Connecting Key output directly to an Audio Output module with a Scale or Scale+Offset seems

    to solve the issue of gliding notes however it could well be a bug with the Ext CV Instrument module.

  • @peterwyst with further testing it’s not a bug.

    Are you using the inbuilt VCA’s to listen back to your external synths?

    This is how I have my routing

    Pitch CV out - instrument - Audio interface return - dRambo VCA’s - Master

    If your routing is similar then what is happening is that we’re hearing a delay

    between the Pitch being adjusting and the return signal as

    the internal VCA’s will always be earlier than the usb audio interface return

    due to usb audio interface latency.

    To adjust for this use this Patch for the envelope gen or gate on the internal VCA’s.

    It’s been set for 44.1kHz to adjust for other sample rates

    type in needed sample rate and then adjust the other number for the delay needed.

    I put the necessary modules in a Processor Rack so that I can save it as a Preset and recall when needed.

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