Proper Cable for UNO Out to Interface In?

[alexpfi1]

Trying to connect my UNO to my audio interface (Roland FA-66). Got quite a bit of hum, regardless of how it’s connected. Don’t have that problem with my Arturia MicroBrute (using a TS ¼") or with 3.5mm headphones on the UNO.
So, what’s the best cabling to connect the UNO to an audio interface?

The manual says:

With the direct computer connection, you can reduce the USB ground noise and other interference by either using a USB isolator or a custom TRS cable into a balanced input on your preamp or audio interface where the ground is not connected balanced at the input side.

Would this work?
Connectors: 3.5 mm TS to 1/4 in TS
http://hosatech.com/product/cmp-300/

Thanks!

[Ryan_IK]

Hey alexpfi1,

Thanks for your post!

Welcome to the IK forums.

The sound you are hearing can be resolved by connecting your UNO Synth to a different power source like 2X AA batteries, a USB battery pack, or a 'wall wart' (Mobile device charging block).

If this is not an option, a good solution would be to 'clean' the signal coming out of your 3.5mm port going into your audio interface. Check out the audio conditioner below. This is an inexpensive solution which will help you with your particular set up. Connect this between your UNO Synth and audio interface.

https://www.amazon.com/Mpow-Ground-Isol ... onditioner

As for the cable to connect to your Audio Interface. Yes, a 1/4" to 3.5mm cable would work for this connection. Unfortunately, I don't believe the Hosa cable you sent over will 'clean' your signal in anyway, but Hosa is a great brand and their cable should work with the above solution.

[alexpfi1]

Hm… The same noise happens in different power scenarii.
Tried plugging the USB cable in a power adapter, using the AA batteries, using a battery pack, and plugging into a computer. There’s a bit of variation in the noise level but it’s never as low as with my MicroBrute.
So maybe it’s not ground noise? Would the “Ground Loop Noise Isolator” reduce the noise in other situations?

[Ryan_IK]

Unfortunately, I cannot say if this would reduce your issue if you are not experiencing a ground loop noise. I can say this is an unusual case to hear any ground loop noise when using battery power or other USB power sources (Other than a computer that is not connected to a power conditioner). Make sure when you test this you remove any USB connections. Make sure to also try a couple output sources to ensure there is nothing wrong with the connection to these sources.

If this information does not help. Please make sure to reach out to Technical Support to see what could be going on here. They should be able to figure this out for you and if necessary help you take advantage of your warranty.

https://www.ikmultimedia.com/contact-support/

[andreas.franke]

Just use an ordinary DI-Box and switch off the ground connection there. Fixed.

[PeriRigos]

Hi...I have the RS232 to TTL device connected to those pins! That's the whole point! I want to use the native COM port. The Arduino will be 50 feet from a computer so I need to use the RS232 connection to load programs etc. Exactly the same as if it was plugged into a USB port.
If I need to use a different pin set and different software then I will need to plug in a regular USB cable everytime I make changes to the program no? Unless I modify the boot loader?

printed circuit boards

[Peter_IK]

Hi...I have the RS232 to TTL device connected to those pins! That's the whole point! I want to use the native COM port. The Arduino will be 50 feet from a computer so I need to use the RS232 connection to load programs etc. Exactly the same as if it was plugged into a USB port.
If I need to use a different pin set and different software then I will need to plug in a regular USB cable everytime I make changes to the program no? Unless I modify the boot loader?

This is about UNO Synth and UNO Drum, not Arduino Uno units.