Norns - Audio In/Out Specs?

Throughout my Norns setup I’ve been curious about the input and output levels, as I’ve noticed that I’ve had to make some adjustments to interface it in my studio. I haven’t seen any specs listed on the Monome site (thought they very well could be). My conclusion is that the output is -10dbV. I’m guessing that the input is the same because I often have to turn down synths so that they don’t clip the Norns input.

Is this everyone’s experience? Are these specs laid out somewhere?
And are there any tricks people have for integrating Norns into a +4 studio?

Thanks.

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Any word on this?
Thanks.

Measuring mine the level seems unbalanced although impedance matched so should be compatible with balanced .

From what I can find though there is this in norns hardware github page which I don’t really understand except if there is a jumper inside :
Inputs

The input jacks are configured for balanced or unbalanced. Input impedance is 10k.

Outputs

The output jacks are configured for balanced or unbalanced. Output impedance is 590 ohm.

Interesting thanks.
Did it mention if it was -10dB? It seems to be just curious if any of this is listed anywhere.

As far as I know the most comprehensive spec list is on ‘norns hardware information’ github page.

By rereading this page I understand the ouput is speced for both balanced or unbalanced by being impedance balanced. So not normally balanced but never the less with good noise rejection .

On impedance balanced inputs the signal level should remain constant, so you should be good . You can read some info on balanced, servo balanced and impedance balanced to clear this thing out. I will try to measure balanced and unbalanced levels to give you specific numbers but its more or less what I explained already.

Okay. Thanks for your help. I check out the GitHub.

Would like to know if these impedance specs also count for shield?

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@Deru no documentation about levels on the monome’s website. I think this is also dangerous for those who don’t know that line levels should not be mixed with modular levels. I think it should be specified that modular hot signals can somehow be harmful. To avoid problems in the modular environment I took a 4ms Listen IO that allows me in both directions to attenuate / amplify if necessary more is convenient for NORNS since it is stereo, although the same work (for attenuation) can also be done by a base doepfer mixer (or a MATHS for example) that has attenuators. the convenient thing about the 4ms module is certainly in the knobs that have two different full scales. + 30db to amplify and 0db to attenuate.

P.S congratulations on your music. Drink it on 1969 remains one of my favorite electronic music tracks☺️

eep! apologies, added just now:

feel free to let me know if there’s anything else missing!

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as always very kind and ready to help☺️
all very clear

Grazie, Emi

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I picked up one of these recently too. The Listen IO is a great friend of norns! It also allows you to use norns as an effect within your eurorack chain, which can be paired with crow for a cv controllable effect programmed in norns :sunglasses:

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Thanks so much @avenir. Cheers!
And thanks for updating the docs @dan_derks.

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@deru sorry for the delay— i just did some scope measurements and they suggest that norns is actually closer to +4dBu:

  • outputting a test sine at max volume i see 3.2vpp
  • patching that back into the input it the norns VU shows about 90%

what specific gear have you been using that has required level adjustment?

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Oh really? Interesting thanks…

I hook it up to my UAD Apollo’s and I find that I need to activate the -10 input setting (vs +4) and turn it up a dB or two to get the gain comparable to my other studio gear. It’s obviously not scientific but that’s what made me ask the question to begin with.

It might be that it is dependent on the app and what engine levels are set at.

For example, I had to set the polysub note levels on the m18s script i made pretty low because there was some internal clipping when I had the two synth lines going with a lot of release on the notes. even -10v on my apollo is not quite enough to bring it up…I have to put a preamp in the insert that gains the signal a bit more. Doesn’t seem to introduce any noise floor or other bad artifacts to the sound tho

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in all cases, make sure in-the-box level settings are approparite.

for hottest output, make sure master output and engine levels are up.

for input: be aware that e.g. MLR sums L+R inputs to each channel. (other softcut-based scripts likely do this as well.)

my measurements in the past have been similar to @tehn’s, with max output peaking at around 1.5 Vp, so ~1 V RMS for a sinusoid.

which is something like 0 dBu, not -10 dBV.

(be aware when looking at reference numbers of the difference between peak / peak-to-peak / RMS, difference between dBv and dBu reference points (and load assumptions,) and the fact that conversion between these units requires knowledge of the signal shape - hence the standard of comparing sinusoids.)

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I always have a doubt that torments me😌
I’d like to ask a questions about how to set up routing in a live set using Fates.

Considering that it should not be a good thing to mix line signals with modular signals, I wanted to understand if I use my ER-301 as a normal mixer connecting for example:

2ch out from morphagene to 301
2ch from Intellijel uVCA where are routed two VCO voice to 301
2ch from FATES to 301
(whereas I would use a limiter or gain from the simple mixer channel of the 301 to bring FATES to an acceptable level)

I would risk problems with the Fates audio codec?
I would be happy if someone would help me understand.

Thanks

You will have no problems with that setup. The ER-301 has analog preamp settings for IN 1-4 so you can bring your Fates up to nearly modular level. I recommend that before patching internal (digital) gain so you get a better signal:noise ratio.

Be cautious with ER-301 modular level outputs to line level gear so you don’t damage your hearing. Even if you put attenuating units on every output, the sample preview functions will play at full volume. Brian at O|D has promised a universal output attenuation setting in a future update.

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Thanks:)
the final signal (mixdown) from ER-301 then goes into a Magneto and then into a zdsp where I have the dry controls so I shouldn’t have problems with the volume too high.

i woud not recommend running modular signals directly into Fates inputs.

Fates uses this codec, which is not rated for input voltages of >5v or so

since the Fates schematics are not published, it is not easy for me to characterize any voltage scaling or limiting that is happening before input audio hits ADC pins, so can only make conservative recommendations.

you can of course measure levels coming onto the board, and compare them with levels at the ADC pins, to make your own determination.

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