# Expression/CV input **URL:** \ **Category:** Super 6\ **Created:** [25 March 2021 20:37 UTC](https://forum.udo-audio.com/t/expression-cv-input/326 "2021-03-25T20:37:35Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![austinbh](https://avatars.discourse-cdn.com/v4/letter/a/ebca7d/32.png) [@austinbh](https://forum.udo-audio.com/u/austinbh)\ **Post date:** [25 March 2021 20:37 UTC](https://forum.udo-audio.com/t/expression-cv-input/326/1 "2021-03-25T20:37:35Z")
I’d like to use my eurorack and ARP 2600 as modulation sources. Does the Expression/CV input accept CV as is? ---
**Author:** ![Udoboe](https://avatars.discourse-cdn.com/v4/letter/u/2acd7d/32.png) [@Udoboe](https://forum.udo-audio.com/u/Udoboe)\ **Post date:** [1 April 2021 20:13 UTC](https://forum.udo-audio.com/t/expression-cv-input/326/2 "2021-04-01T20:13:19Z")
Me too. Is the expression input a Tip-Ring-Sleeve socket or a 2-pole Tip-Sleeve jack? What are the connections and voltages it puts out or accepts? I don’t want to damage my Super 6 by connecting it to Euro Rack and burning something out. ---
**Author:** ![MOOGelPackung](https://avatars.discourse-cdn.com/v4/letter/m/a3d4f5/32.png) [@MOOGelPackung](https://forum.udo-audio.com/u/MOOGelPackung)\ **Post date:** [28 April 2021 23:09 UTC](https://forum.udo-audio.com/t/expression-cv-input/326/3 "2021-04-28T23:09:16Z")
The FAQs say you can use any standard expression pedal. A standard expression pedal contains a poti with its hot end to ring and its wiper connected to the tip. So you could simply measure the ring voltage of the connector and than apply any voltage from zero to this voltage to this input. And if you put a 1kOhm resistor in series to the input you could be sure that you don’t destroy any input. ---
**Author:** ![MOOGelPackung](https://avatars.discourse-cdn.com/v4/letter/m/a3d4f5/32.png) [@MOOGelPackung](https://forum.udo-audio.com/u/MOOGelPackung)\ **Post date:** [29 April 2021 12:52 UTC](https://forum.udo-audio.com/t/expression-cv-input/326/4 "2021-04-29T12:52:29Z")
By the way: Connector ring voltage is +5V, so 0…5V CV should fit perfectly! ---
**Author:** ![Udoboe](https://avatars.discourse-cdn.com/v4/letter/u/2acd7d/32.png) [@Udoboe](https://forum.udo-audio.com/u/Udoboe)\ **Post date:** [1 May 2021 16:16 UTC](https://forum.udo-audio.com/t/expression-cv-input/326/5 "2021-05-01T16:16:40Z")
@MOOGelPackung Yes, sleeve is -Ve, ring +5v and tip +0.4v. In other words, only a passive device, not a CV or Gate sequencer should be connected. Maybe there’s a Euro Rack module that modulates an incoming voltage, controlled by CV or Gate? ---
**Author:** ![MOOGelPackung](https://avatars.discourse-cdn.com/v4/letter/m/a3d4f5/32.png) [@MOOGelPackung](https://forum.udo-audio.com/u/MOOGelPackung)\ **Post date:** [1 May 2021 17:15 UTC](https://forum.udo-audio.com/t/expression-cv-input/326/6 "2021-05-01T17:15:55Z")
> [@Udoboe](#): > > … tip +0.4v. In other words, only a passive device, not a CV or Gate sequencer should be connected. Tip is an input, if you measured +0.4V than this is just the neutral voltage of the input stage or the voltage of your pedal when open. The potentiometer in the expression pedal works as a voltage divider and deliveres any voltage between 0 (sleeve) and +5V (ring) to this input. With my pedal i measured any voltage between 0 and 4.5V (what seems to be a limit of the pedal), depending on pedal position. … and the input does not care about what this voltage comes from. On my Super6 the connector is labeled with “EXPR./CV” so one could expect that it is intend to be used as a CV input, even if it is not mentioned in the manual. You only should take care to have 0V at the input when turning on the Super6 and to not go below 0V or above +5V. ---
**Author:** ![ryan](https://avatars.discourse-cdn.com/v4/letter/r/a8b319/32.png) [@ryan](https://forum.udo-audio.com/u/ryan)\ **Post date:** [7 May 2021 14:33 UTC](https://forum.udo-audio.com/t/expression-cv-input/326/7 "2021-05-07T14:33:51Z")
hi this thread is just what i was looking for .thanks all for sharing this knowledge. what would ? could the consequences of sending more than 5 volts , or less than 0v. . could it potentially harm the synth … im not confident enouugh in my eurorack to be sure i could send an lfo that wouldnt go into to - 5 . could use a max for live device i guess and then midi learn a knob on the S6 that wasnt being used in the chain … or a little controller i guess … i have a volt meter i spose i could do some testing with … do the guys from UDO ever join in these threads, and comment? ---
**Author:** ![MOOGelPackung](https://avatars.discourse-cdn.com/v4/letter/m/a3d4f5/32.png) [@MOOGelPackung](https://forum.udo-audio.com/u/MOOGelPackung)\ **Post date:** [7 May 2021 14:53 UTC](https://forum.udo-audio.com/t/expression-cv-input/326/8 "2021-05-07T14:53:44Z")
> [@ryan](#): > > what would ? could the consequences of sending more than 5 volts , or less than 0v. . > could it potentially harm the synth … This can only be answered by one who knows the synth hardware in detail, so you should ask UDO support for that. If you don’t want to apply pitch values (which do not allow to be wrong by some percent) but only effects … and if you are familiar with soldering, then you could easily build some kind of protection with a resistor (something around 1kOhm) and two diodes. > [@ryan](#): > > do the guys from UDO ever join in these threads, and comment? At least sometimes … allready saw comments (e.g. regarding the MOD AMOUNT knob).