OT inputs, CV, and attenuators

Elektron Gear Octatrack
1

Hi, this question is a result of ignorance with relative voltage levels.

I have a 0 coast, and I am wondering if I can mix 2 outputs into the OT using either 0 coast’s voltage MATH or a passive attenuator like this.

0 coast has a stereo line level output, but it is a mono synth, so it doesn’t make much sense to use two of OT’s inputs. However, if you patch for example the EON from slope to balance (audio in), you can get some awesome sounds from modulating slope (a cycling AR envelope) in audio range.

So, can I use attenuation to patch EON straight into OT? Is this safe? I’ve read line level to be 0.3V - 2V, 0.5V - 1V, or 750mV depending on the source. What? How does this relate to OT inputs +8dBu max, if at all? If anyone knows any good articles or youtubes on this stuff please throw them in!

2

I bet you can go directly from 0 Coast into OT…
We’re talking line level audio, right?

3

Yeah, you can go straight from the line level out on the 0 coast, of course.

But i’m asking what if I want to also patch an audio rate 0V - 8V gate from 0 coast to OT using an attenuator.

4

Haha, sorry^^
I actually read your post twice, because I thought you must be talking about cv, but yeah…I need more coffee…

Sorry can’t help with that, I’m not really firm with such stuff, but may I ask what exactly you wanna do?

5

By triggering the slope (cycling envelope) with an oscillator and patching straight into the audio input on the 0 coast, you can get some interesting sounds. The 0 coast outputs two mixed signals at line level - default triangle wave and output of the multiply section. You can replace the triangle wave using audio in as mentioned.

I want to patch the 0V - 8V signal straight into the OT input using an attenuator, so I can get 3 sources out of the 0 coast at once.

1 Like
6

+8dBu equals 1.95 volts RMS or 5.50 volts peak-to-peak

To handle 8 volts without a transformer the input should be able to accept +20.28 dBu without clipping

I don’t know anything about the 0-coast as far as impedance and delivered current is concerned, maybe you should ask on a modular forum.

You might get away with a passive transformer based DI box that has a -20dB /-40 dB attenuation switch

7

Hey, thanks for the info. I’ll go trawl some modular forums.

So could I not use a passive attenuator like I linked to? I thought scaling the voltage down was exactly how they work. Do I need to know the impedance and current to prevent damaging the inputs?

8

There’s little chance of damaging the input circuitry, but well, not knowing what we’re dealing with, better safe than sorry. That’s why I suggested a transformer based DI because it will isolate both devices. Even a dirt cheap one will do: audio quality is not an issue in this case.