Cgs114 dusg grounding issue?

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lilnoah95
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Cgs114 dusg grounding issue?

Post by lilnoah95 » Wed Apr 22, 2020 4:57 pm

I just build the dual universal slope generator by ken stone and it works perfectly except that the v/octave and vc input jacks have a super unstable connection when I play from my key step. If I plug the key step into another module in my case (for instance with its gate output) this stabilizes the dusg cv input connections. Seems like a grounding issue, but I have no idea what to do about it. Any advice would be super appreciated.

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the bad producer
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Re: Cgs114 dusg grounding issue?

Post by the bad producer » Wed Apr 22, 2020 5:07 pm

Have you any more information on build / patch? Is it a euro module with minijacks, or is it built with bananas? Sounds like the Keystep and DUSG are not sharing a common ground connection between power supplies, and you are making this connection when you plug the Keystep into another module - which I assume is sharing the same PSU as the DUSG?

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Revok
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Re: Cgs114 dusg grounding issue?

Post by Revok » Wed Apr 22, 2020 5:13 pm

I've had similar issues with the Keystep but it was always the plug not being in all the way in. Sometimes it feels like the cable is fully inserted on the Keystep but it needs a little extra push to get the ground connection.

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cleaninglady
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Re: Cgs114 dusg grounding issue?

Post by cleaninglady » Wed Apr 22, 2020 6:26 pm

If you're going Banana to Minijack then you'll need to make a split cable as in the image below.
This one has a ¼ inch jack end but the concept is the same for minijack."nana GND to sleeve ,'nana Signal to tip.
I tie the GND end to the GND of the Power input jack and the whole thing to the Chassis. I put a banana plug in the side of the enclosure and thats connected to those GND's.
IMG_7989.jpg
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lilnoah95
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Re: Cgs114 dusg grounding issue?

Post by lilnoah95 » Fri Apr 24, 2020 6:40 am

Thanks for the responses, the dusg is eurorack with 3.5mm jacks, and badproducer you described the setup accurately. The keystep and eurorack have different PSUs, (plugged into the same extension cord if that matters). The keystep works perfectly well with all my other modules, and the dusg works perfectly with the rest of my modules. I've double checked to make sure that all of the cables are fully plugged all the way in.

I have the dusg in self looping mode as an oscillator and with the keystep pitch output in the VC or V/oct inputs, it makes a noisy, unstable connection cutting in and out especially when i wiggle the cable around the cable. If I connect another output of the keystep (e.g. gate out) to any different module in my case, the problem goes away and the connection between the dusg and the keystep works perfectly. The issue does not go away if i plug in the keystep gate out to another input on the dusg. It's not the biggest problem of all time, because the dusg is otherwise fully functioning, and I don't really plan on playing it as an oscillator with my keystep, but I'd like to sort it out in order to prevent future bugs when patching outside my eurorack case. I can post a video if that would help describe the problem better.

I really appreciate your help, hope your staying safe and healthy!

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Revok
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Re: Cgs114 dusg grounding issue?

Post by Revok » Fri Apr 24, 2020 7:42 am

Are the sleeve lugs of the the jacks on the DUSG connected to the 0V on the PCB?

lilnoah95
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Re: Cgs114 dusg grounding issue?

Post by lilnoah95 » Fri Apr 24, 2020 8:01 am

yes, my multimeter shows connection between the sleeve lugs all the way through the pcb back to the ground of my eurorack PSU... so confusing

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