Hi all
Is it safe to run modular level signals straight into the Digitone 2 inputs or do I need a line level converter in between?
Cheers
I think @plragde might have already done this.
It’s probably fine but don’t take my word for it.
What are your modular levels looking like? If it’s 20+dbu then it might be an issue, so I guess it depends.
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I haven’t actually done it myself yet, but I get the impression that others have. The math depends on the nature of the incoming signal in ways that I don’t quite understand. If you are relying on hard clipping in your modular rack with a 20+Vpp signal, you might get further hard clipping in the DN2. I doubt you will do any damage. A more typical 10Vpp signal should be fine.
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Thanks for checking in on it.
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It is kind of maddening that most module manufacturers do not document the voltage ranges of their inputs/outputs, but that is where we are. Frap Tools does, bless them, and also further technical information like what is considered a trigger.
I guess the point of modular is only to collect in beautiful cases and occasionally turn it on otherwise seems as though they would all get on board with that 
Yeah, it’s safe, I do it regularly. You will just want to set the input volume around 30ish.
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Nice one 
It’s not as if manufacturers of line-level devices co-operate fully (witness TRS MIDI A/B versions, and other incompatibilities) or document fully, for that matter. A bigger modular company has an incentive to keep people within their ecosystem (all of their modules should play well with each other). A smaller company is one or two people who don’t want to scare potential buyers off by publicizing sensible limitations, when no one else does. It’s yet another variation on “Can’t we just all get along?” Apparently not.
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Also when you start talking about things like filters and VCA’s the output voltage can be hugely variable. The power rails are +12v and -12v, so that is the maximum and minimum that could generally be expected to be able to come out. Oscillators generally go from -5v to 5v. Gates and triggers are usually anywhere from 5v to 8v. But once you get into filters and VCAs and other audio processing stuff, it gets really hard to specify output levels. Like a filter with no resonance with a ±5v oscillator input will output around ±5v. But once you add resonance it can get up to like ±8v. And if you really amplify the input the output could start getting pretty close to the power rails of the system.
Despite specifically designing a case around having several buffers of saturation/attenuation to make things safe for his Digitakt II, when I first went around to my friend’s with it we still inevitably ended up massively overloading the input 
There was digital clipping galore and I took longer than I should to realise, since the case was also based around jank digital sound sources. The DTII coped with it fine though, at least for that brief time.
Please don’t take this as a “Yeah, absolutely, worry not and crank it up” though, just a data point
Absolutely, which is why I wrote “20+Vpp” above. I have a Mordax DATA oscilloscope, so I can at least measure what my case is producing, but I still don’t know how downstream devices can cope. I recently bought a Zoom H1 XLR recorder because it has 32-bit recording via dual-range ADCs and 24dBu headroom in the specs, but I have yet to put it to a full test. Usually I use an output module scaling things to line level, but I have fewer of those than cases now…!
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My general expectation is that pro audio gear should be able to take eurorack levels without damage. Eurorack outputs generally can’t put out much power in terms of watts, it’s generally just large voltages driven by relatively puny (compared to like a speaker amplifier for instance) op amps. The vast majority of eurorack modules aren’t going to be able to output more than like 15mA at 12v. Depending on how the input section of the thing you are plugging into works, it could likely clip, but I would be somewhat surprised if damage was caused.
I don’t know for sure, but I think Elektron’s devices use an analog gain adjustment stage on the inputs, so if there is a signal that is way too loud coming in and can clip the inputs, I believe the external volume control will be able to reduce that to the point where it is no longer clipping the inputs. I know for sure that I can take a signal directly from eurorack and reduce the level inside the Elektron device (generally DT2 or DN2, but they are all somewhat similar) enough to get a clean signal in the mixer though. If the volume control were all digital I would expect it to just change the volume of the clipped input signal, rather than reducing the input so that it doesn’t clip. Then again, maybe they just have a ton of headroom on the digital inputs.
So how many dBu’s is a typical eurorack output level then? Professional audio gear should be rated to handle up to +24dBu, many prosumer gear cannot reach this. Consumer stuff and puny battery powered devices struggle to reach even a fraction of this level (cue all the “why is input so low” threads online…)
I dont know how to convert peak to peak voltage to dBu’s… I could google it I suppose…
This was a pretty useful Modwiggler thread when I was looking into it ages ago.
+24 dBu is equal to 34 volts peak to peak (±17v). So that is like 5 extra volts more than eurorack can make, so anything rated for +24dBu input should be totally safe with eurorack.
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I think generally speaking if your audio source isn’t powerful enough to drive unpowered speakers then your inputs are safe and at worst will clip. It’s a combination of voltage and amperage that will break stuff. Pretty sure one of the most common causes of a broken input in the audio world is someone mixing up a cable with phantom power and plugging it into an input.
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Short answer, totally fine to run eurorack gear into digitone.
Just attenuate the signal on the digitone end.
Ive run my eurorack straight into my octatrack, and digitone, no problems at all.
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Yes, completely fine. It will be a bit hot, but fine. You can attenuate at the Digitone, or if you either have a couple unused VCAs with manual offsets, or a couple passive attenuators you can use those pre-Digitone. Any of the above are fine really. I have a little 4-6 channel Mackie VLZ that I put between them usually just because it’s there, but I’ve also gone straight in.
Mainly you don’t want to exceed power rails of the i put op amps, and staying below a bit is better. +/-5V is well below.
Thank you for that. Just for curiosity’s sake, how many volts peak to peak would be close to a +18dBu - +20dBu range? Since that is a typical dBu range for stuff such as Elektron’s, Maschine+ etc