Presonus Eris E5 hum

[mxlv900]

Hi everyone. I'm new to this forum so if I'm doing any of this wrong feel free to tell me.

I bought a Topping E30 DAC to hook up to my pair of Eris E5. The problem is that I experience a fairly loud hum/buzzing sound. I hooked them up through some THX RCAs that I had lying around in the house. The noise occurs independently of the input and the power source. All my devices are plugged in different power outlets.

Previously, I was running TRS cables to the monitors from a Focusrite Scarlett Solo 3rd gen. The speakers were dead silent. To try to solve the issue, I tried lowering the Eris' gain and to increase the DAC's volume, which helped (noise floor kind of stuff?). I still haven't had the chance to test the DAC on another pair of monitors.

edit: The noise also occurs if the DAC is turned off but still plugged in.

My questions are the following:
1. Would the problem be the E30, the E5s, the RCAs, or a mix of them three all together?
2. I have a Temblor T10 on the way. Will connecting the RCAs to the Temblor and then hooking up the E5s with TRS from the Temblor help?
3. What are your guesses on how to solve this issue? I've heard it's quite common to experience some noise while using RCAs with powered monitors.

Thank you for your time, any help is very much appreciated!

 

[Restin]

I had buzing and static with the Sub8 + Eris 3.5's. Tried an unbalanced DAC, and the issue was still there. Optical may fix the noise. Going fully balanced (Schiit Modius) should fix the noise as well. I am still new to the whole thing, so wait for another reply.

 

[AnalogSteph]

Any time you put both balanced and unbalanced inputs on a device, one of them is going to be a compromise. Unbalanced audio is calling for floating audio ground and device manufacturers are going to great lengths to keep parasitic coupling low, balanced audio works best when audio ground is earthed. You cannot have both at the same time. Studio gear will generally opt for the latter, so any unbalanced DAC that's not galvanically isolated internally (generally not an option below $300 or so) will give trouble.

If it's any consolation, the RCA inputs on a Topping A90 are similarly problematic.

The solution would have to depend on why you picked the E30 in the first place and what your fidelity requirements are. If you just needed SPDIF input, a Behringer HD400 plus cabling (RCA --> TS in, TRS --> TRS or XLR out) should still be cheaper than the price difference between the E30 and the aforementioned Modius. If USB input from a computer is all that's needed, I would pick a USB audio interface again (the Scarlett Solo 3rd gen actually would have been perfectly fine hardware wise, though anything bus-powered can be finicky e.g. when it comes to port and cable selection).

 

[MikeJ]

It's been 7 years since I had this exact problem with Yam's HS80M (don't have them anymore btw) and I fixed it using a custom cable I made for myself - RCA to XLR with ground pin lifted if I remember correctly, worked flawlessly. Google for this phenomenon (ground loops) and you should be able to find a solution. In essence, seems like you're picking ground loop somewhere from the PC/DAC to the active Eris speakers. Good luck.

 

[mxlv900]

Any time you put both balanced and unbalanced inputs on a device, one of them is going to be a compromise. Unbalanced audio is calling for floating audio ground and device manufacturers are going to great lengths to keep parasitic coupling low, balanced audio works best when audio ground is earthed. You cannot have both at the same time. Studio gear will generally opt for the latter, so any unbalanced DAC that's not galvanically isolated internally (generally not an option below $300 or so) will give trouble.

If it's any consolation, the RCA inputs on a Topping A90 are similarly problematic.

The solution would have to depend on why you picked the E30 in the first place and what your fidelity requirements are. If you just needed SPDIF input, a Behringer HD400 plus cabling (RCA --> TS in, TRS --> TRS or XLR out) should still be cheaper than the price difference between the E30 and the aforementioned Modius. If USB input from a computer is all that's needed, I would pick a USB audio interface again (the Scarlett Solo 3rd gen actually would have been perfectly fine hardware wise, though anything bus-powered can be finicky e.g. when it comes to port and cable selection).

Thanks for the useful reply. I mainly chose the E30 since I needed optical input for a TV and a preamp with a remote to control volume from a distance. It was getting a lot of love overall on this forum and I decided to give it a go. The Behringer HD400 seems like a great solution for this problem in my particular situation, I really do hope it works.

 

[mxlv900]

Update: The Behringer HD400 solved my problem.