Background/static Noise occurring when recording an electronic keyboard

tensyume

New member
Hello All,

I have a setup where I have an audio interface (Presonus Audiobox USB) where I connect Left Out and Right Out of my Nord Piano 3 Keyboard to its Mic, Instrument Input (1,2 on the image below).

243007000000000-00-500x500.jpg

The cable I am using to connect the two:
Amazon.com: Hosa CPP-201 Dual 1/4 inch TS to Dual 1/4 inch TS Stereo Interconnect Cable, 3.3 feet: Musical Instruments

I tried recording the sound today using Logic Pro, and I am getting a small background noise in the recording. I have attached my recording below. I play the same song 3 times, each time adjusting the knobs on the audio interface (last one has all the knobs turned down all the way to the left).

I have 48v phantom power off as well.

I don't think knobs are the problem and I am just stuck.

Am i always expected to have this kind of background noise? Or is there a way for me to get rid of them?

Thank you !
 

Attachments

  • backgroundnoise.mp3
    2 MB · Views: 74
Hmm. What's your DAW project settings? 44.1kHz/24-bit I hope. And, what levels are you recording at? The MP3 is pretty hot.

it's tempting to question the piano as the source in this case. Do you hear this noise in the Phones with the knob twisted all the way to Inputs?
 
Hmm. What's your DAW project settings? 44.1kHz/24-bit I hope. And, what levels are you recording at? The MP3 is pretty hot.

it's tempting to question the piano as the source in this case. Do you hear this noise in the Phones with the knob twisted all the way to Inputs?

You were right. The levels were pretty high and there was clipping going on. I tried recording again with less level where there would be no clipping. The clipping went away but white noise did not go away, because if I set the volume to the same decibel level, the amount of whitenoise is same before lowering level and after lowering level. (Attached file for reference)

And yes, even when the mixer knob is on inputs, i still hear the same white noise. I m not sure if it will be my keyboard's problem though because it is brand new and all the cables that are connecting the audiobox USB and the Nord Piano 3 are brand new. (only thing not brand new are audiobox usb interface itself and the usb that connects to the Mac I have)

Edit:

I just tested my audiobox USB with nothing plugged in except for phone and USB, and mixer turned to inputs all the way, and to no surprise, there was no noise at all.
 

Attachments

  • backgroundnoise_lesslevel.mp3
    2 MB · Views: 25
Last edited:
You could try a stereo DI and use the DIs earth lift to see if that gets rid of the noise?

Alan.

I can't hear it Al ! (sup! sup!) even looping the tiny bit of silence at the beginning but the noise floor is an very poor -50dBFS or so, not good for a direct connection. (is there a bit of an Art Tatum influence in there? Nice!)

So, looks like a hum/earth/ground loop and I see the Nord has a 3 pole IEC mains conn'? So, usual suspects are a grounded PC or/and earthed active monitors. The first, cheapest step is to break the earth/shield connection on the J-Jack cable twixt kbd and interface. Not possible with moulded plugs so, two options. Chop them off ONE end and fit solder jobbys but INSULATE the screen. Or just chop one end (two plugs) and twist together the hot centre wires, cleaning back the screens, bit O Gaffer. Give that a go, if it works make a better job of it all.

A DI box would work Alan but for a wideband device like organs (guitars have a shit F response but nobody cares) OP would need an expensive one to avoid LF loss or/and distortion. In any case a 1:1 traff isolator would be better than a mic level DI box.

Can post pikkies if required.

Dave.
 
I cut out the piano, and then normalised the remaining noise to make it LOUD, and I cannot hear any hum at all, so there is no point lifting grounds as there's nothing to remove bar plain old fashioned hiss. Surely we're looking at the capability of the interface - if we assume the Nord is hiss free and good, then the only real cause must be the nord is simply not loud enough and the pre-amp is making up the gain, and that is where the hiss is coming from. It's worth trying a DI, but it does rather depend on the quality of the mic level amplification. DIs never improve signal to noise, but they do improve matching - so if the mic performance is good, the DI will optimise it. If the line level inputs don't have enough gain - because they're labelled 'instrument', suggesting guitars, keyboards etc - and kind of expecting noisy sources anyway - then maybe that's the problem. If it was me, I'd have the Nord output very high on the output level, and then back off the preamp gain and compare that.
 
I cannot find a noise specc' for the Audio box Instr input but I cannot believe a company of the calibre of Presonus would make one this such an appallingly poor noise floor! Try this.

Set the gains on the ABox for -18dBFS from the Joe and then switch off the Nord (not ideal but bear with) now record the remnant noise. My bet is it will drop to better that -90dB.

Ideally you should do this test with 1meg terminated screened jack plugs but just a bare screened plug should work.

And yes Rob, COULD be gain staging but I still don't think the Presonus is that noisy. (Err? How did you cut out the piano? Polarity flipped one side? If so that would also cancel the hum I cannot hear!)

Dave.
 
I do hear the hiss and it sounds like OP doesn't get anything like that if the piano isn't plugged in. It's pretty low, but certainly not where I'd want it to be for a solo piano recording.

Reading up on this AI, it says on their site it's not designed for line-level input, and you should use a DI. So, I'd get a couple of DIs with PAD switches, and try that, and soon, since they say line level can damage that model interface!

Can I connect a line level source to my AudioBox USB or 22VSL? – Knowledge Base | PreSonus

P.S. Here's a couple DIs (I have and use) that cover a price range where you'll find what you need. I'd check reviews, but for home use, the inexpensive ones are often fine.

Livewire SPDI Passive Direct Box with Attenuation Pad | Guitar Center

Radial Engineering ProDI Passive Direct Box | Guitar Center
 
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I do hear the hiss and it sounds like OP doesn't get anything like that if the piano isn't plugged in. It's pretty low, but certainly not where I'd want it to be for a solo piano recording.

Reading up on this AI, it says on their site it's not designed for line-level input, and you should use a DI. So, I'd get a couple of DIs with PAD switches, and try that, and soon, since they say line level can damage that model interface!

Can I connect a line level source to my AudioBox USB or 22VSL? – Knowledge Base | PreSonus

P.S. Here's a couple DIs (I have and use) that cover a price range where you'll find what you need. I'd check reviews, but for home use, the inexpensive ones are often fine.

Livewire SPDI Passive Direct Box with Attenuation Pad | Guitar Center

Radial Engineering ProDI Passive Direct Box | Guitar Center

Well! Unless that was written by a lawyer Presonus have gone WAY down in my estimation. Yes, for sure 'Instrument' levels are not STUDIO line levels but in the world of HR they are bloody nearly the same. Guitar pedals typically run at about -10dBV (316mV) but the PP3 powered devices can put out +10dBV 3 volts and that's 'rms'. The peak to peak voltage is around 8V (it is the pk-pk that will 'blow' front ends) . Then there is "our" HT pedal range that uses a valve and can put out at least +20dBu or over 22V pk-pk! Since these devices are by definition, designed to drive the INSTRUMENT inputs of guitar amplifiers they would not be expected to cause any damage. If you are thinking "Well, valves are tough" true but there are a LOT of all sstate amps around and all but 3 of 'ours' use a chip at the front, never had one buggered.

I cannot believe Presonus have never seen a reverse biased diode protection circuit? (or you can use back to back Zeners).

Bottom line: This SHOULD work.

Dave.
 
Well! Unless that was written by a lawyer Presonus have gone WAY down in my estimation. Yes, for sure 'Instrument' levels are not STUDIO line levels but in the world of HR they are bloody nearly the same. Guitar pedals typically run at about -10dBV (316mV) but the PP3 powered devices can put out +10dBV 3 volts and that's 'rms'. The peak to peak voltage is around 8V (it is the pk-pk that will 'blow' front ends) . Then there is "our" HT pedal range that uses a valve and can put out at least +20dBu or over 22V pk-pk! Since these devices are by definition, designed to drive the INSTRUMENT inputs of guitar amplifiers they would not be expected to cause any damage. If you are thinking "Well, valves are tough" true but there are a LOT of all sstate amps around and all but 3 of 'ours' use a chip at the front, never had one buggered.

I cannot believe Presonus have never seen a reverse biased diode protection circuit? (or you can use back to back Zeners).

Bottom line: This SHOULD work.

Dave.
Well, it's not just the protection, it's the fact there's actually no line-level input, so everything going into those combo jacks is geting a ton more gain than required, hence the noise. I kept wondering how OP was turning the level "down all the way" but I was still seeing a waveform!

I think most consumer AIs with only combo jacks that are mic (XLR) and line (TRS) in, with a switch to flip for Instrument input, or perhaps they're mic/instrument, with a Line switch. If there's no separate TRS line input in the back, and no switch in the front, you should assume something has been left out.
 
I do hear the hiss and it sounds like OP doesn't get anything like that if the piano isn't plugged in. It's pretty low, but certainly not where I'd want it to be for a solo piano recording.

Reading up on this AI, it says on their site it's not designed for line-level input, and you should use a DI. So, I'd get a couple of DIs with PAD switches, and try that, and soon, since they say line level can damage that model interface!

Can I connect a line level source to my AudioBox USB or 22VSL? – Knowledge Base | PreSonus

P.S. Here's a couple DIs (I have and use) that cover a price range where you'll find what you need. I'd check reviews, but for home use, the inexpensive ones are often fine.

Livewire SPDI Passive Direct Box with Attenuation Pad | Guitar Center

Radial Engineering ProDI Passive Direct Box | Guitar Center

O my.. Thank z lot guys. Thats a Lot of jargons in there.. May I get an ELI5 spoonfeed version of what I should do to get sexy hum free sound? (like what to buy, what I don't need anymore, what I should plug in where...) DI, earthy ground and all these terms aren't connecting for me.
:(

Thanks guys!
 
O my.. Thank z lot guys. Thats a Lot of jargons in there.. May I get an ELI5 spoonfeed version of what I should do to get sexy hum free sound? (like what to buy, what I don't need anymore, what I should plug in where...) DI, earthy ground and all these terms aren't connecting for me.
:(

Thanks guys!
So, as basic as I can put it, the level (voltage) of signal coming from the piano is too high for your Presonus USB interface. That level needs to be reduced to a microphone or instrument level *before* it gets to the Presonus. In cases where you can't use a different interface that supports a line-level (higher voltage) input, and that input is unbalanced (two conductor cable) to begin with, the most common way to do that in this case would be to use a direct box, or DI for short.

You could optionally go trade your interface in on something else if that's simpler for you, but it must have 2 line-level inputs. The Steinberg UR22 is one, Focusrite 2i2 (v2) is another. There are more.

If you keep your current interface, you'll need to acquire two direct boxes, or perhaps one stereo one. Buying two of the first items in that list of two would solve that. Then, you plug each of the L-R channel cables into the 1/4" INPUT jack. The XLR output jack of each DI is then connected to the Presonus with a short XLR cable, like one of these (you'd get a 3' or 6' one probably):
Livewire Essential XLR Microphone Cable | Guitar Center

Finally, and the important part, you need to set the PAD switch on each one of those DIs to -20dB, so the level of signal going to the Presonus is mic level.

I'm not necessarily pushing Guitar Center or LiveWire products, but I have picked them up when in a pinch because they have a store locally, and they seem to work just fine. Feel free to find equivalent products wherever you shop, but make sure the DIs have PAD switches!

Hope that helps.
 
So, as basic as I can put it, the level (voltage) of signal coming from the piano is too high for your Presonus USB interface. That level needs to be reduced to a microphone or instrument level *before* it gets to the Presonus. In cases where you can't use a different interface that supports a line-level (higher voltage) input, and that input is unbalanced (two conductor cable) to begin with, the most common way to do that in this case would be to use a direct box, or DI for short.

You could optionally go trade your interface in on something else if that's simpler for you, but it must have 2 line-level inputs. The Steinberg UR22 is one, Focusrite 2i2 (v2) is another. There are more.

If you keep your current interface, you'll need to acquire two direct boxes, or perhaps one stereo one. Buying two of the first items in that list of two would solve that. Then, you plug each of the L-R channel cables into the 1/4" INPUT jack. The XLR output jack of each DI is then connected to the Presonus with a short XLR cable, like one of these (you'd get a 3' or 6' one probably):
Livewire Essential XLR Microphone Cable | Guitar Center

Finally, and the important part, you need to set the PAD switch on each one of those DIs to -20dB, so the level of signal going to the Presonus is mic level.

I'm not necessarily pushing Guitar Center or LiveWire products, but I have picked them up when in a pinch because they have a store locally, and they seem to work just fine. Feel free to find equivalent products wherever you shop, but make sure the DIs have PAD switches!

Hope that helps.


Hi Keith,

Thanks for your response again.

I understand a bit now I think. So the output coming out of Left out and RIght out of my Nord keyboard are line inputs (or outputs depending on what perspective) which carry stronger power than mic/instrument inputs and thus it needs to be lowered down to that level to be properly used.

I guess what I don't get now is why I would need 2 of those DI's. They seem to take in 2 inputs for 1 box. Can i just plug left and right line inputs to the 2 slots? Or is it for the stereo effect that I need to plug left input into one box and right input into another?

And by Pads, you mean the switches that switches between -20dB, -40dB, .. so on ? or the ground switch?

Another question I have is if you lower from line inputs to mic/instrument input, would it lower the quality or something negative in some way that I would be just better off buying a new audio interface like the ones you suggested? (steinburg and focusrite)

Sorry if these are dumb questions.. Just genuinely curious and you are great at explaining things haha
 
As I said way back, get a stereo DI, then you will have a left and right input in a single DI, then if there are any ground loop hums or digital ground loop static the earth lift switch should fix it. The inputs of the Presonus are instrument inputs and are designed for guitars and basses which have a different impedance input to the keyboard.

Alan.
 
I guess what I don't get now is why I would need 2 of those DI's. They seem to take in 2 inputs for 1 box. Can i just plug left and right line inputs to the 2 slots? Or is it for the stereo effect that I need to plug left input into one box and right input into another?

Although they have two separate physical inputs, they only have one signal path. You'd want to keep your L+R separate for sure.
If it's going to cost you two DI boxes and 2 cables, my preference would be to upgrade AI.

Having said that, it looks like the Nord has USB for audio and/or midi. Have you ever used that?
 
Although they have two separate physical inputs, they only have one signal path. You'd want to keep your L+R separate for sure.
If it's going to cost you two DI boxes and 2 cables, my preference would be to upgrade AI.

Having said that, it looks like the Nord has USB for audio and/or midi. Have you ever used that?

I never tried Midi because I thought line out was of higher quality? someone recommended me from nord forum to use the line out. Not sure. I am not sure what you mean by USB? Nord does have a USB out, but I use that to upgrade the Nord software and add new piano sounds, not for outputting sounds.
 
Oh, I just looked through the manual. It appears USB doesn't carry audio. Never mind! ;)

Yes, the dual DI you linked will work well.
 
haha thank you.

Buying a new audio interface is 4~5 times more expensive it seems than buying a stereo DI. I will probably hold off on that :P

If I do want to record voice or other instruments while recording my piano, I would need a bigger AI with more inputs right?
 
If I do want to record voice or other instruments while recording my piano, I would need a bigger AI with more inputs right?

Yes, that's right. Your present interface will only do two channels simultaneously.

The DI will sort out your immediate needs. If you think you'll be branching out into multitrack recording any time soon, maybe consider an interface upgrade.
Either works. :)
 
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