spluttery noise on audio interface inputs

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ricecrispies

Member
When recording with my audio interface (a Focusrite Scarlett 2i2), I get spluttery noise (as opposed to the steady hiss of white noise). Normally it is not noticeable except on the input level meters on my DAW where it looks much louder than it sounds, but recently I have started processing my signal with fuzz and overdrive effects, which make the underlying noise very prominent and destructive to what I am trying to do.

I had previously assumed that is was related to another problem I have, which is that I can't record from any signal source that has an independent connection to the mains (such as my bass amp) because I get lots of buzzes and squeaks, but yesterday I tried attaching the interface to my laptop when it was running on battery power with absolutely no wired connections to anything else, and I still got the spluttery noise.

My question is: Is this a problem with the audio interface that can be fixed by replacing it, or could the source of the problem lie somewhere else?
 
So you're saying you only hear the noise when you're in record mode on your DAW right? Does it occur on both inputs? You do not hear it on playback of recorded tracks when you have the playback volume up higher? When in record mode with nothing in any input do you still hear it? Has this been a problem since you first got the AI or did it develop later? Have you tired to move the laptop and the AI to a different room or power source / outlet? Maybe you can post a sample of the problem here. I wouldn't just go and buy a new AI until I was reasonably sure it was the problem.

As for not being able to use any signal source that uses a different power main........now that seems like a problem that calls for a complete check of your local outlets.....etc.

Bottom line.........give us more info if you can please.
 
First test, can you post a clip of the noise? (320k MP3 attachement please!) If it cannot be recorded that in itself narrows down the source.

The hum you are getting with mains connected gear is the very common ground/aka, hum/earth loop problem and there are two basic ways to fix it.
One is buy a two channel transformer isolator, quite expensive for good quality. The other is some modified signal cables. Can you solder? If not I suggest you learn if you want to progress messin' with audio kit.

N very B!! You might get advised to remove a MAINS CABLE EARTH WIRE. NEVER EVER DO THIS! Not so easy now with moulded plugs anyway.

Dave.
 
Of late, my Tascam interface which is elderly, but I like it - is doing odd things a bit like this. Theres a sort of 'puttering' noise that I can hear when the material has quiet bits, or gentle sounds. After a while the puttering develops into a gentle distortion, then into a crackle. Powering off and on seems to cure it, but it's getting progressively worse. Oddly, if I've left the system powered up overnight, by morning windows has replaced the tascam driver with an ASIO one that sits on the system for the occasional other device, and this when running works fine with the Tascam quality wise, apart from terrible latency - around a second. Which makes me think it's the driver. Updating it has not solved the problem. At the moment I live with a power recycle every couple of hours.

I'd recognise the sound if you could post an example, but I guess actually recording the device causing the problem isn't the easiest thing to do, depending on how your system is wired.
 
No Dave - just when the unit uses the official latest Tascam driver, who is pretty good latency wise, but appears very close to the edge and then it's as if the driver gets tired and has a rest. The ASIO generic driver works fine with it, apart from limiting it to 2 channels in and out - but the latency is very poor. The Tascam one when it works is transparent, but repowering, or pulling the USB and replugging is a bit annoying - but the description the OP has here does sound a bit similar.
 
Thanks for all your comments.

I've tried attaching the audio interface to my laptop running on battery power with no cables connecting it to anything else and I still get the same problem.

I've discovered that the problem is much worse when my microphone is connected (Rode M3), even when it is switched off.View attachment with mic (switched off)-002.mp3

I don't hear a difference between the left and right inputs.

But even without the microphone the noise is still there.View attachment without mic-002.mp3 It is very noticeable when I run the signal through some VST guitar effects.View attachment guitar and effects.mp3. It is not steady white noise. As I said, it is spluttery.

When there is no cable attached to the input I get something a bit different, a bit like the noises I get when I connect gear that is connected to another power supply.View attachment left input nothing connected.mp3 Again it is much more noticeable when run through the same guitar effects. View attachment left input nothing connected with effects.mp3
 

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  • right input nothing connected.mp3
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I think sadly, you have a real old fashioned fault that need the experts to fix it, as in a trip back to the manufacturer/agent.
 
Is the Gain way up on the Focusrite? There's quite a bit of noise in that very last attachment, for nothing attached, though it sounded like white noise to me, and not anything I'd call "spluttery" so you're saying it only happens with something plugged in? Is the switch on INST?

The clip with the guitar at the beginning - was it normalized or are you recording at that level where the guitar basically almost clips?

Does it happen with a microphone plugged in as well?
 
rob aylestone said:
I think sadly, you have a real old fashioned fault that need the experts to fix it, as in a trip back to the manufacturer/agent.
Click to expand...
Could you be more specific? What kind of fault are you referring to? And do you mean a fault with the audio interface or with something else? Given how much a repair would be likely to cost I may just need to replace the device, but I need to be sure that I replace the right piece of equipment.
 
keith.rogers said:
Is the Gain way up on the Focusrite? There's quite a bit of noise in that very last attachment, for nothing attached, though it sounded like white noise to me, and not anything I'd call "spluttery" so you're saying it only happens with something plugged in? Is the switch on INST?

The clip with the guitar at the beginning - was it normalized or are you recording at that level where the guitar basically almost clips?

Does it happen with a microphone plugged in as well?
Click to expand...

I put the input gain up to full when I was just recording the noise.

The clip with the guitar isn't at the input level (which I set low enough not to clip). It's the volume after a chain of effects has been applied (it's one of the Rammstein stacks in Guitar Rig). I posted it because the spluttery noise becomes very prominent after being put through an overdrive (which is the reason, now that I have bought myself a guitar to which I want to apply lots of distortion, that this noise has become such a problem). Obviously what I want is for any noise that gets put through the guitar effects to be smooth like white noise, so that it is less distracting, and to be at as low a level as possible.

When my microphone is plugged in, whether or not it is switched on, the noise is much louder, as you can hear in the sample I attached earlier.
 
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The sound it's making when the mic is plugged in is not a common one, and reminiscent of the kinds of faults we used to get fairly often usually caused as capacitors charge and discharge - so clearly it's a front end issue that requires a path between pins 2 and 3. Could be in the preamp, or possibly something adrift with the Phantom power? Does switching that make a difference?
 
rob aylestone said:
The sound it's making when the mic is plugged in is not a common one, and reminiscent of the kinds of faults we used to get fairly often usually caused as capacitors charge and discharge - so clearly it's a front end issue that requires a path between pins 2 and 3. Could be in the preamp, or possibly something adrift with the Phantom power? Does switching that make a difference?
Click to expand...

Turning off phantom power has solved the problem of the relatively loud noise when a mic is plugged in, and fortunately my mic can run off battery power. However the noise that I hear with the guitar is still there.

One other piece of information, in case it is relevant, is that the audio interface sometimes hums. I actually have it sitting on a piece of styrofoam to make the hum less obtrusive. On rare occasions I have to tap the box with my hand to get it to quieten down.
 
HOW TF can an interface fed with only regulated DC HUM FCS? Not doubting you chap but that is very weird.

The good news is that if the "Applied technical acceleration" fixes the fault the interface MUST be at fault so get it fixed or replaced.

Dave.

---------- Update ----------

HOW TF can an interface fed with only regulated DC HUM FCS? Not doubting you chap but that is very weird.

The good news is that if the "Applied technical acceleration" fixes the fault the interface MUST be at fault so get it fixed or replaced.

Dave. (given up trying. 'Ave two!)
 
Aha!± Just had a thought. I wonder if the problem is not the 2i2 at all, but the computer having trouble supplying the 5V supply for the interface at adequate current. The change when phantom is turned on was a clue? I had a colleague who had some him issues with an interface that worked on his main computer but didn't on his other. He had a weird digital buzzy sound on everything he did. Very quiet, but there. I just text him and it was a 2i2. Can you try it on a different computer and see if the problem goes away? Worth doing to eliminate power supply issues - but the general 'non audio' noise problems you have, that don't sound familiar to any of us could be caused by the computer being right on the edge of it's current limit - and if you go over, you could get induced noise, worse s/n ratio or other strange artefacts produced as the 2i2 struggles.
 
rob aylestone said:
Aha!± Just had a thought. I wonder if the problem is not the 2i2 at all, but the computer having trouble supplying the 5V supply for the interface at adequate current. The change when phantom is turned on was a clue? I had a colleague who had some him issues with an interface that worked on his main computer but didn't on his other. He had a weird digital buzzy sound on everything he did. Very quiet, but there. I just text him and it was a 2i2. Can you try it on a different computer and see if the problem goes away? Worth doing to eliminate power supply issues - but the general 'non audio' noise problems you have, that don't sound familiar to any of us could be caused by the computer being right on the edge of it's current limit - and if you go over, you could get induced noise, worse s/n ratio or other strange artefacts produced as the 2i2 struggles.
Click to expand...

Good call Rob but I cannot see how hitting the 2i2 could cure a PC supply fault? Still, got to be worth a try.

Dave.
 
Corroded or high res DC connector issue? Surely it couldn't be as simple as squirting the socket and connector with cleaner and in/outing it a few times? Or maybe a dry joint on that pin? Weird one!
 
rob aylestone said:
Corroded or high res DC connector issue? Surely it couldn't be as simple as squirting the socket and connector with cleaner and in/outing it a few times? Or maybe a dry joint on that pin? Weird one![/QUOTE

Yes, PCB based connectors do go dry joint but that would not account for a MECHANICAL hum?

To misquote Mr Oldfield "Buggered if I know!"

Dave.
Click to expand...
 
The hum from the audio interface, when it happens, doesn't sound like 50 Hz. I put it down to circuit whine, although it's not something I know much about.

I tried connecting the interface to my laptop and still got the same symptoms, although that doesn't have a hugely powerful power supply either. But the power supply on my desktop computer was a relatively inexpensive one that I bought because it was meant to be relatively quiet. I can't remember the power rating. So do you think getting a better power supply might solve my problem?
 
ricecrispies said:
The hum from the audio interface, when it happens, doesn't sound like 50 Hz. I put it down to circuit whine, although it's not something I know much about.

I tried connecting the interface to my laptop and still got the same symptoms, although that doesn't have a hugely powerful power supply either. But the power supply on my desktop computer was a relatively inexpensive one that I bought because it was meant to be relatively quiet. I can't remember the power rating. So do you think getting a better power supply might solve my problem?
Click to expand...

My NI KA6 has vastly more I/O than the 2i2 and yet pulls just under 500mA from a USB port (measured with a USB V/I meter) Half an amp is the standard for USB and I doubt that any computer will deliver less than that.

Dave.
 
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