CV from Reason to hardware

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Jagwah
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14 Sep 2018

I'm still working on setting up my external synth to receive CV from Reason and it works already to some degree.

What I would like to know is how can I measure the CV data on the hardware side? I'd like to know that what is coming from Reason is still holding itself together after being converted and translated to the real world. Even something basic like minimum and maximum values would be useful in setting up.

Using Eurorack, is there a typical device or method for measuring such things?


Thanks! :)

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Boombastix
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13 Oct 2018

CV means control voltage, so you measure voltage. Different synths need different voltage, so check the synth manual for that.

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demt
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13 Oct 2018

im intrigued whats the name of the reason to cv adapter if you please, praps its neutron friendly
Reason 12 ,gear4 music sdp3 stage piano .nektar gxp 88,behringer umc1800 .line6 spider4 30
hear scince reason 2.5

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LABONERECORDINGS
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17 Oct 2018

We've been messing around with CV from Reason to trigger our Sherman Filterbank with no issues at all. Some soundcards actually appear to be geared up to do such things. The MOTU 2408 (Mk1 and Mk3, we've tested and used both) is a great addition, plus the PCI424 card comes with some onboard tools, namely an oscilloscope and the usual FFT metering. We do it round trip so we send out from Reason to the MOTU 2408 into a tape channel on our Mackie d8b, which is then looped back via optical back to the MOTU for monitoring visually (not via speakers) and we have the channel setup with fader down and sending to an aux channel output. We know where our 0dB level is so we know how much is being sent 'truthfully' to the Sherman. We've also build a couple of guitar pedal PCBs into a 2U unit where one part is a CV generator / sequencer (3- or 4-step) and we can patch the CV from that back into Reason. Pretty cool stuff to see external gear with true CV pipe down audio cables into the computer and watching Reason device modulate by the hardware. Latency timing we'll need to check but we know via (ahem) Cubase that audio round trip from PC DAW to MOTU to d8b (via optical) to hardware (via audio cable) back to d8b (audio cable 2) to MOTU (optical from d8b) measures pretty quickly, so we're pretty happy with that (and knowing the lag we can always offset latency in Reason or Cubase accordingly, especially when using outboard gear with the Rack)

Try using Melda MMOscilloscope on an audio input in Reason to analyse the signal back in through your soundcard so you can see the CV.. after all these sort of signals are all voltages (audio is a voltage down the cable to the air piston aka speaker) so you should be fine to do that.

http://www.expert-sleepers.co.uk/siwacompatibility.html for a good starting list of devices people have tested already, but to us in theory you should be fine with whatever you use, as long as it's a decent device, anything that has a credible backing as a pro company (so no crappy cheap 3.5mm laptop output socket and the like, and decent cables too to keep the noise out)

To actually monitor with true hardware ala oscilloscope... you'll need something to parallel or pass through the signal. Passing through might induce a touch of latency while parallel lets you visualize as close as possible what is being sent. Audio cable lengths much match if you're going for total precision (length of cable differences can of course offset time differences because of distance variances, so like for like would be better of course). Personally, if you know the time lag, you can always do the software method with the loopback so that you can zoom out and have a view of what is happening, plus you can use our ears as that's the final nail that will pin down if something is right. Eyes are great but ears help with mojo :D

Maybe ask the synth manufacturer directly your questions as they have better understanding of what is going on under the hood - most are really helpful these days opposed to black-arting of yesteryear. Give them your full signal chain setup from software to soundcard / output to the synth input, plus have a look at your signal output manual and maybe speak with them too if the manuals don't give enough info (stuff like signal to noise ratio, noise floor etc).

Just some ideas to play with

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LABONERECORDINGS
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17 Oct 2018

http://www.sengpielaudio.com/calculator-db-volt.htm

Use the middle calculator for dBV to voltage. 0dBV = 1 volts (remember volts can be alternating so take 0dBV as 'peak' level).

-6dbV = 0.5volts which is the right power to voltage scaling (logarithmic), so on your scope if you're hitting -6dB on the meter you're pumping out 0.5volts (or you should be).

-12dbV = 0.251volts....
-18dbV = 0.125volts...

Find out the max your synth can take as a CV input before it 'clips'.

This is good to test your actual output signals especially if you have an output level control on the unit itself. Setting the unit up to be 'pro' (+4) vs 'consumer' (-10) would help get a good signal level too, because you can always turn it down if it's too much anyway.

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Jagwah
Posts: 2549
Joined: 16 Jan 2015

18 Oct 2018

demt wrote:
13 Oct 2018
im intrigued whats the name of the reason to cv adapter if you please, praps its neutron friendly
If you mean the Behringer Neutron then yes you should be able to have it communicate with Reason - which opens up a new world of possibilities.

From the Reason side you need something like this: https://shop.propellerheads.com/product ... io-bundle/

That allows me to send CV and audio data through a USB cable, which is then sent to my ES-8 module on my synth (http://www.expert-sleepers.co.uk/es8.html)

The ES-8 module allows this data to be sent out via the Eurorack standard 3.5mm patch cables.

As you are looking at a standalone synth I am not sure what you need in place of the ES-8.

I'm sure it can be done, and merging those two would be amazing!

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Jagwah
Posts: 2549
Joined: 16 Jan 2015

18 Oct 2018

LABONERECORDINGS wrote:
17 Oct 2018
We've been messing around with CV from Reason to trigger our Sherman Filterbank with no issues at all. Some soundcards actually appear to be geared up to do such things. The MOTU 2408 (Mk1 and Mk3, we've tested and used both) is a great addition, plus the PCI424 card comes with some onboard tools, namely an oscilloscope and the usual FFT metering. We do it round trip so we send out from Reason to the MOTU 2408 into a tape channel on our Mackie d8b, which is then looped back via optical back to the MOTU for monitoring visually (not via speakers) and we have the channel setup with fader down and sending to an aux channel output. We know where our 0dB level is so we know how much is being sent 'truthfully' to the Sherman. We've also build a couple of guitar pedal PCBs into a 2U unit where one part is a CV generator / sequencer (3- or 4-step) and we can patch the CV from that back into Reason. Pretty cool stuff to see external gear with true CV pipe down audio cables into the computer and watching Reason device modulate by the hardware. Latency timing we'll need to check but we know via (ahem) Cubase that audio round trip from PC DAW to MOTU to d8b (via optical) to hardware (via audio cable) back to d8b (audio cable 2) to MOTU (optical from d8b) measures pretty quickly, so we're pretty happy with that (and knowing the lag we can always offset latency in Reason or Cubase accordingly, especially when using outboard gear with the Rack)

Try using Melda MMOscilloscope on an audio input in Reason to analyse the signal back in through your soundcard so you can see the CV.. after all these sort of signals are all voltages (audio is a voltage down the cable to the air piston aka speaker) so you should be fine to do that.

http://www.expert-sleepers.co.uk/siwacompatibility.html for a good starting list of devices people have tested already, but to us in theory you should be fine with whatever you use, as long as it's a decent device, anything that has a credible backing as a pro company (so no crappy cheap 3.5mm laptop output socket and the like, and decent cables too to keep the noise out)

To actually monitor with true hardware ala oscilloscope... you'll need something to parallel or pass through the signal. Passing through might induce a touch of latency while parallel lets you visualize as close as possible what is being sent. Audio cable lengths much match if you're going for total precision (length of cable differences can of course offset time differences because of distance variances, so like for like would be better of course). Personally, if you know the time lag, you can always do the software method with the loopback so that you can zoom out and have a view of what is happening, plus you can use our ears as that's the final nail that will pin down if something is right. Eyes are great but ears help with mojo :D

Maybe ask the synth manufacturer directly your questions as they have better understanding of what is going on under the hood - most are really helpful these days opposed to black-arting of yesteryear. Give them your full signal chain setup from software to soundcard / output to the synth input, plus have a look at your signal output manual and maybe speak with them too if the manuals don't give enough info (stuff like signal to noise ratio, noise floor etc).

Just some ideas to play with
Hey dude thanks for your input here.

It makes a lot of sense to measure what is sent back to Reason after being sent out, I think this is probably the solution I need.

As I am using a modular synth, I was hoping there might be a typical module trick or method for measuring data like this.

I am using an ASUS Essence STX 2 and there's no mention of it on the Expert Sleepers compatibility page.

I have successfully sent data from Reason to the synth, but it appeared weaker hence my want to measure it and possibly calibrate it.

I'll get on to Expert Sleepers and explain my set up and another issue I have, and hopefully they can help too.

Thanks again dude I'll update you if I get anywhere ;)

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