Need help eliminating the noise

[aduman]

So I've bought a Fulla 2 to be able to connect both my lsr 305s and hd598s. I'm using it on a desktop pc, connected it through a front panel usb port (USB 3.0/2.0) both cause the same issues.). Speakers are connected with a 2x1/4'' to 1x1/8'' cable to the Fulla's variable pre-amp out. The headphones are fine without any noise at all, however I'm getting a lot of noise through the speakers. There is a constant hum. Moving the mouse also creates a hard to hear high pitched noise. Whenever I launch a game I also get a combination of different types of noises which seems to be parallel to the GPU load. The speakers are basically unusable at the moment. Anyway, here is what I've tried so far to eliminate the noise: I try to run all my stuff through a single power strip so I tried to separate the speakers to another power strip which is connected to another outlet but that did nothing. Tried running the PC directly through the wall outlet and the speakers from a power strip - no dice. Went through all the usb ports, no difference. Opened up the PC, removed the motherboard to check the standoffs for grounding issues, corrected a loose one, again... no difference. I then connected the speakers directly to my phone with the same cable to troubleshoot and there was indeed no hum. Crystal clear sound which is what I'm after. I know I could've gone with optical but fulla was way too tempting for my setup and budget.

I'd really appreciate your help. Thanks very much in advance.

Btw. I live in Germany so I don't know if a cheater-plug is doable with the plug types here.

Edit: This is the cable i'm using to connect the speakers:
https://www.thomann.de/gb/cordial_cfy_30_wpp_long.htm

Also, would a powered usb hub fix this?

[anothertom]

At a guess, the cable between the fulla and the speakers is running next to the power cable for the computer?

[aduman]

Just now, anothertom said:

At a guess, the cable between the fulla and the speakers is running next to the power cable for the computer?

Nope, I tried to isolate that cable by locating it on top of the desk. The psu cable is under the desk, at ground level.

[anothertom]

Could you try plugging the speakers into a phone directly, but without moving the cable, and then do something GPU intensive.

 

Could you also try plugging the phone into the fulla's line input and then switching to that input, and doing something GPU intensive.

 

Either way, this definitely sound like a EMI issue rather than a grounding issue, especially as it's fine through headphones but not the speakers. The solution would be to use a balanced connection between the fulla and the speakers.

[aduman]

19 minutes ago, anothertom said:

Could you try plugging the speakers into a phone directly, but without moving the cable, and then do something GPU intensive.

 

Could you also try plugging the phone into the fulla's line input and then switching to that input, and doing something GPU intensive.

 

Either way, this definitely sound like a EMI issue rather than a grounding issue, especially as it's fine through headphones but not the speakers. The solution would be to use a balanced connection between the fulla and the speakers.

 

That's what I've been thinking too. I connected the speakers to the phone, launched a game and no noise or any kind of interference came out of the speakers. I can't fulfill your second request though as I don't have the cables for that, sorry. Is there a way to 'clean' the signal without getting something like a scarlett 2i2? Budget is a bit tight atm.

[anothertom]

Just now, aduman said:

 I connected the speakers to the phone, launched a game and no noise or any kind of interference came out of the speakers.

Hmm... not what i expected. Are you able to run the phone through the fulla?

[aduman]

3 minutes ago, anothertom said:

Hmm... not what i expected. Are you able to run the phone through the fulla?

 

Wait a minute.. When I connect the speakers to the phone and run a game like you wanted me to try before, there is actually the same noise but it is way quieter than before. I just expected the same level of noise and didn't focus properly before. What does this mean?

[anothertom]

6 minutes ago, aduman said:

 

Wait a minute.. When I connect the speakers to the phone and run a game like you wanted me to try before, there is actually the same noise but it is way quieter than before. I just expected the same level of noise and didn't focus properly before. What does this mean?

Potentially that part of the issue is through grounding (despite all you've tried to fix that) and that part is through interference.

 

What might be worth trying is using a passive DI box between the fulla and the speakers, unfortunately this means some spending. the DBX DJDI should be available in most regions and looks to be the cheapest that i'd actually trust to work, you'll then need 2 xlr cables between the DI and the speakers and the shortest 3.5mm to dual 1/4'' you can find.

 

The only other useful advice i can think of is to check that internal USB header cables are routed away from any power cables, and again externally.

 

I can't say this will definitely fix 100% of your problem, but it's as much as i can think would have any effect.

[aduman]

4 minutes ago, anothertom said:

Potentially that part of the issue is through grounding (despite all you've tried to fix that) and that part is through interference.

 

What might be worth trying is using a passive DI box between the fulla and the speakers, unfortunately this means some spending. the DBX DJDI should be available in most regions and looks to be the cheapest that i'd actually trust to work, you'll then need 2 xlr cables between the DI and the speakers and the shortest 3.5mm to dual 1/4'' you can find.

 

The only other useful advice i can think of is to check that internal USB header cables are routed away from any power cables, and again externally.

 

I can't say this will definitely fix 100% of your problem, but it's as much as i can think would have any effect.

Thanks for your help, I really appreciate it. I also stumbled upon those DI box thingies when I was reading through other threads. Would they degrade or color the SQ in any way? They also have pretty high resistance numbers (600 ohms on most) on the ins and outs. Is that a bad thing? lol

 

As for the usb cables, I don't think I can route them any differently. The front usb header cable is just above the psu but there is no other way it can be routed. Good suggestion though, thanks.

[anothertom]

4 minutes ago, aduman said:

Thanks for your help, I really appreciate it. I also stumbled upon those DI box thingies when I was reading through other threads. Would they degrade or color the SQ in any way? They also have pretty high resistance numbers (600 ohms on most) on the ins and outs. Is that a bad thing? lol

No and No. A decent read on the issue of impedance matching, and why having massive input impedance isn't a bad thing until you're trying to drive something.

 

But a good question to ask, well done.

[aduman]

19 minutes ago, anothertom said:

No and No. A decent read on the issue of impedance matching, and why having massive input impedance isn't a bad thing until you're trying to drive something.

 

But a good question to ask, well done.

Again, many thanks for your help. Some people would have ridiculed me for asking a question of that nature but your response was indeed very kind. I'll definitely give that a thorough read, still trying to wrap my head around all the terms. I'll get a DI box and report back here with the results. Have a good one!

 

Edit: After reading that 600 ohms now sound like a measly number lol thanks for sharing it.

[aduman]

@anothertom, after doing some research I have now two options and I need your opinion to decide which way to go to rid my system of noise:

 

. A passive DI box (Palmer PAN04) with the required cables (damn XLR cables really add to the cost lol) - this costs around 100€. I was going to go with DBX DJDI but unfortunately that wasn't available on Thomann.

 

. An iFi iDefender with iPower:

 

http://ifi-audio.com/portfolio-view/accessory-idefender3-0/

http://ifi-audio.com/portfolio-view/accessory-ipower/

 

Costs the same in total.

 

I would really appreciate your input, thank you in advance.

 

 

[anothertom]

45 minutes ago, aduman said:

@anothertom, after doing some research I have now two options and I need your opinion to decide which way to go to rid my system of noise:

 

. A passive DI box (Palmer PAN04) with the required cables (damn XLR cables really add to the cost lol) - this costs around 100€. I was going to go with DBX DJDI but unfortunately that wasn't available on Thomann.

 

. An iFi iDefender with iPower:

 

http://ifi-audio.com/portfolio-view/accessory-idefender3-0/

http://ifi-audio.com/portfolio-view/accessory-ipower/

 

Costs the same in total.

 

I would really appreciate your input, thank you in advance.

Are you unable to buy from amazon.de? An alternative to the palmer PAN04 would be two Behringer DI400P, which would be ~ €20 cheaper, two 6m xlr cables for €10.

 

Those power supplies would only be cleaning the power into the DAC, you'd still have any electromagnetic interference that's there.

[aduman]

2 hours ago, anothertom said:

Are you unable to buy from amazon.de? An alternative to the palmer PAN04 would be two Behringer DI400P, which would be ~ €20 cheaper, two 6m xlr cables for €10.

 

Those power supplies would only be cleaning the power into the DAC, you'd still have any electromagnetic interference that's there.

 

Oh I thought those were mic cables and wouldn't work with the speakers, for some reason they are on different categories in the thomann site. I'd buy from Amazon but just wanted to get it all from thomann, they also ship pretty quick and offer great customer service. So it's decided then, I'll get the Palmer. Would those cables work with the lsr305s though? I was looking at these under speaker cables category but they're triple the price for some reason:

https://m.thomann.de/gb/cordial_ctl_3_fm.htm?o=17&search=1498755792

 

There is also a warning there to not use these with active speakers. Which cable would be the right one?

 

Thanks for your response. I realize I've been asking lots of questions so thanks again for being so helpful.

[anothertom]

11 minutes ago, aduman said:

There is also a warning there to not use these with active speakers. Which cable would be the right one?

 

Thanks for your response. I realize I've been asking lots of questions so thanks again for being so helpful.

So back in the day, before speakon became the prevalent standard, some people used XLR connectors on passive speakers (i.e. between an amplifier and the speaker), this needs thicker cable than a mic or instrument and will cause a large signal loss if used for a mic or instrument. The cable you linked is one of these, don't buy it. It's more expensive as it's got more copper in it, as well as high quality connectors.

 

Since the LSR305 are active (they have an amplifier built in) the signal sent to them is at something near line level, and as such only needs a normal mic/instrument xlr cable.

[aduman]

4 hours ago, anothertom said:

So back in the day, before speakon became the prevalent standard, some people used XLR connectors on passive speakers (i.e. between an amplifier and the speaker), this needs thicker cable than a mic or instrument and will cause a large signal loss if used for a mic or instrument. The cable you linked is one of these, don't buy it. It's more expensive as it's got more copper in it, as well as high quality connectors.

 

Since the LSR305 are active (they have an amplifier built in) the signal sent to them is at something near line level, and as such only needs a normal mic/instrument xlr cable.

 

Alright then. I'll get the Palmer and those cables. Thank you very much for all your help.

[aduman]

@anothertom The stuff arrived today. The noise is gone it's absolutely crystal clear now! Thanks a lot for your help.

[anothertom]

58 minutes ago, aduman said:

@anothertom The stuff arrived today. The noise is gone it's absolutely crystal clear now! Thanks a lot for your help.

Woohoo! Happy to help.