Analog Four mk2 | using cv-in-signals to achieve fm

Elektron Gear Analog Keys/Four
#21

right i read wrong

#22

i just looked into the manual and at the TECHNICAL INFORMATION section it says:

48 kHz, 24-bit D/A and A/D converters

iam not sure if this relates to the cv-in conversion… but if so than it should work to freqs up to 24 khz .

#23

I would believe that it wont give good results as the cv is sampled first and the internal modulation rate in the A4 is not high enough to give good FM results.

Alex.

#24

right. btw how high is the internal modulation rate? lfos can go how fast?

i dont really understand why elektron didnt implemented more fm possibilities (beside fm via lfo) in mk2. maybe they dont want it to be that way…maybe they will do it in future os updates. who knows.

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#25

It is high enough for LFO and Envelopes. But not FM.

Maybe it is up to 5kHz I don’t know.

#26

The A-D and D-A converters only apply to the effects section (and the outputs of the LFOs and EGs).

The synth is called analog 4 for a reason. The CV inputs are analog, and if they’re really limited to 16Hz as suggested above, then that’s crap design. The VCOs are analog, and if they are capable of audio-rate fm via a fast LFO, then I’d expect to be able to do similar via the CV inputs.

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#27

thanks for your feedback, lenny.

no answer from electron so far regarding my question regarding adc…
anyway, will definitely give this a try and report here, as soon as my a4 mk2 arrived.

#28

The A4 has DCOs not VCOs and for whatever reason it is difficult to implement FM between DCOs, hence the pseudo FM Elektron introduced by using the digital LFOs running at audio rates at harmonic ratios relative to the modulated DCOs.
Maybe a similar restriction applies here?

#29

ah, i see. thats why adc of the cv- in signal is needed at all.

#30

guys, elektron just confirmed that the modulation bus is not fast enough for routing audio rate signals to modulation destinations. or it least it is not faster than an lfo that modulates an osc… :palm_tree:

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#31

Oops. You’re absolutely right. I’d overlooked that they are DCOs.

Re audio-rate FM, is the difficulty you mention down to the choice of too low a sample rate for the oscillator’s D-A converter (as seems to be the case here) or some other factor inherent in DCO design ?

Presumably there’s a good reason Elektron didn’t just bypass the oscillator’s D-A converter, injecting the analog CV input directly into the VCO core. I’m guessing the CV In signal is easier to route (to a variety of destinations) if it’s in the digital domain.

#32

So it should be okay up to a few hundred Hz. The LFOs can run fairly fast.

Has anyone with a mkII actually tried this ?

#33

This is amazing. . .

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#34

Did elektron ever get back to you about limiting on the CV inputs? I imagine it’d probably be safe to send outside +/- 5V so long as it’s within the power rails of the unit and seeing as it can send +/- 10V I’d think it’d at least be safe (although pointless) to send that

#35

Edit.

Always good to check if it’s in the manual :wink:

#36

Thanks, I guess I worded my post badly as I’m aware the manual states +/- 5V for the CV input but I’m just wondering if it’s safe if you were to accidentally send it say a signal that was +/- 10V. I think most modern equipment is designed to be protected against over voltage but I don’t want to assume and then break an expensive piece of kit. I guess I’ll just ask Elektron directly.

#37

Ah, I see…

As far as I understand at least the audio inputs are diode protected against too hot signals (stated here)

This might in some way apply to the CV inputs, too. But yes, if you could get an answer from support would make it less speculative.