Does anyone else get a weird humming/crackling sound from their Apogee Duet?

[jonnypowell]

I've had this problem since I bought it..
it's not really loud, but loud enough to be quite annoying..

Any ideas as to why I have this?

[Alex Specht]

have you tried to raise the buffer setting?

[stevelindsay]

It's coming from the actual unit itself is it, not via monitors? Does it do it from the moment it's plugged in via firewire, or does it warm up into it? I picked up a Duet couple of weeks ago and I'd say definitely not normal. Have you tried a different firewire cable? These things are buss-powered, probably worth trying that to start in case it's a faulty lead. Are there other f/wire devices sharing the buss?

SteveL

[embrionic]

i noticed a slight noise and crackling from mine and it ended up that when one of the xlr cables was loose and happened to be touching medal it added that noise.

Maybe something to do with the fact that the unit is unbalanced?

also since installed I get an intermittent weird hard-to-track-down rf through certain pre/cable combinations, but I have not verified it is is the duet or something else.

[macleodgrant]

this does appear to be the fact that the unit is unbalanced on the outputs.

the simple way i know of to avoid this it to ensure that every piece of equipment that is connected is only connected to one plug point. as soon as you have another piece of equipment connected through another plug point then ground loops and hums are possible

it's the biggest issue for me with the DUET and why i can't integrate it properly into my system. i chose a long time ago to run a balanced studio to ensure i can avoid all these issues

[jonnypowell]

Originally Posted by macleodgrant

this does appear to be the fact that the unit is unbalanced on the outputs.

the only way i know of to avoid this it to ensure that every piece of equipment that is connected is only connected to one plug point. as soon as you have another piece of equipment connected through another plug point then ground loops and hums are possible.

it's the biggest issue for me with the DUET and why i can't integrate it properly into my system. i chose a long time ago to run a balanced studio to ensure i can avoid all these issues

What do you mean exactly by "having every piece of equipment that is connected is only connected to one plug point"...?

[macleodgrant]

Originally Posted by jonnypowell

What do you mean exactly by "having every piece of equipment that is connected is only connected to one plug point"...?

i'm not totally clued up on this since i chose the easy way out (going balanced) to avoid these complications.

i have ensured that my most basic setup (converters, monitors, monitors controllers and computer are all on one plug point. i can then use my Duet with this part of the system without getting the ground loops and hums, etc!

when you add additional equipment that is plugged in at a different plug point and connect this to your system and where the system is unbalanced then this is how the ground loops start. it's exactly that, a loop from ground to ground at 1 or many plug points

one way round this is to have only one ground connection to a single plug point and cut the ground connection at all others. you need to be very careful when doing this because if you disconnect that piece of equipment from the rest of the equipment then it may no longer be grounded through the main plug point anymore and you can get shocked & seriously injured. this is no joke so look it up

[macleodgrant]

here's some info
Q. What is a Ground (Earth) Loop?

[pedrodash]

I'm getting this noises too...
it's a ****ing pain, i'm having to use my MBOX to record...
it's funny, the digi hardware is working better then the Apogee.
I really don't know what to do, and I already checked every single piece of equipment too..

[macleodgrant]

Originally Posted by pedrodash

I'm getting this noises too...
it's a ****ing pain, i'm having to use my MBOX to record...
it's funny, the digi hardware is working better then the Apogee.
I really don't know what to do, and I already checked every single piece of equipment too..

if you're not getting it with your mbox and you're using balanced connections then it definitely is to do with earthing and the fact the DUET doesn't have balanced outs!

[pedrodash]

Originally Posted by macleodgrant

if you're not getting it with your mbox and you're using balanced connections then it definitely is to do with earthing and the fact the DUET doesn't have balanced outs!

I'm sure it is not it. I'm getting this noises even with my macbook unplugged from a power source and with only one thing plugged into the duet.
i made this test by pluggin in a sm57 and after that an electric guitar. i recorded it and then plugged my headphones, to make shure that only one thing was plugged in.
and then, playing back the audio, i can hear this clicks.. it seems like a digital glitch or something like that.

[jeremycox]

i noticed this VERY loudly when the breakout cables were laying across an AC power cable.

[embrionic]

i think people may be talking about different things here. a hum may be caused by the device and may be an audio path grounding issue, while the crackling more than likely sounds like an issue with the devices driver settings in your setup (latency/buffer etc).

[macleodgrant]

Originally Posted by pedrodash

I'm sure it is not it. I'm getting this noises even with my macbook unplugged from a power source and with only one thing plugged into the duet.
i made this test by pluggin in a sm57 and after that an electric guitar. i recorded it and then plugged my headphones, to make shure that only one thing was plugged in.
and then, playing back the audio, i can hear this clicks.. it seems like a digital glitch or something like that.

well that does remove the possibility of earthing for your case and the earthing issue should only present it self on the output of the device at the main outs not headphone outs

as jeremycox mentioned, when cables are going over AC lines then it can pick up interference. what about the cable and how long is it? does it happen with different cables too? yours doesn't sound like the earthing issue i experience

[jonnypowell]

OK, I've just noticed something...

I'm running the outs of my DUET to a Mackie Big Knob.
I only get the humming problem when I have other synths plugged in to the big knob. As soon as I remove the synths it's gone. I only have the DAW mix selected ut still the humming/crackling comes through. The same is true the other way around. If I've soloed the synth I here humming/crackling until I remove the Duet outs.

So... Any ideas on how to fix this? The outs from my JP-8 & Voyager are both balanced.

[narco]

yeah, it sounds like an earthing problem jonny,does the big knob have balanced inputs?

if it does (I'm not sure of the consequences if it doesn't) then try lifting the sleeve on one end of the cables going between the big knob and the synths (as you say they have balanced outputs too)

The sleeve of the cable is earthed and connects the two bits of equipment, hence causing the possibility of earth loops

By this I mean open up the plug at one end of the cable, there will be three wires connected to the plug, find the part of the plug that is connected to the shield (the outside part of the cable) and remove it so it is no longer connected to the plug, (do this on one end only), make sure its not touching anything else either. This should break your earth loop.

I also assume that the synths and the big knob have an earth prong on their power supplies, so they can still get their earth from somewhere

NB: I'm not a tech, although I'm quite confident about this I wouldn't want to take responsibility, perhaps check with someone else first..

ps, oh and plug everything into the same wall socket..


narco

[macleodgrant]

i have the big knob and that's the problem i get. i have to disconnect everything from the big knob to get rid of the noise

[Al Rogers]

I had a problem like you describe and it turned out I had an XLR cable where it was wired wrong. No pins were crossed but the shield was carrying a signal instead of serving as a ground. I rewired the cable correctly and no more noise.

-Al

[pedrodash]

Originally Posted by macleodgrant

well that does remove the possibility of earthing for your case and the earthing issue should only present it self on the output of the device at the main outs not headphone outs

as jeremycox mentioned, when cables are going over AC lines then it can pick up interference. what about the cable and how long is it? does it happen with different cables too? yours doesn't sound like the earthing issue i experience

already tried without any cables at all...
the glitches are happening even with nothing plugged into the ins or outs.
I guess I'm a "lucky" one and bought a defective unit.

[embrionic]

Originally Posted by pedrodash

.. already tried without any cables at all...
the glitches are happening even with nothing plugged into the ins or outs...

Hi pedrodash,

I just want to restate that you may be getting offers of help to two different types of problems (someone please correct me if I have misread this thread.)

If you are getting "glitching" from your DUET with nothing plugged into it, then it is likely that you have a driver issue and your audio hardware/device drivers are not set up correctly. That is a very different problem from a bad cable or the fact that the unblanced DUET may be little sensitive to certain setups... Can you enlighten us on what kind of system you have? software/computer etc?

Then we may be able to offer some other solutions that might work.

There does appear to be some occasional hum/interference issues that other DUET users have noted (including me), but it is starting to sound to me like you are experiencing something else.

As a fellow DUET owner I am happy to try and help but we need some more info. Is it only when playing music or anytime? Can you post an mp3 of the sound you are hearing, as recorded through your system?

[jonnypowell]

Originally Posted by macleodgrant

i have the big knob and that's the problem i get. i have to disconnect everything from the big knob to get rid of the noise

Yipp, that's exactly what I have to do, which would mean it's certainly a grounding issue and not driver related..
Maybe we should write to Apogee with a link to this thread?

[little-dreamer]

I too get an annoying humming noise from my 1 month old duet. I'm going to troubleshoot this weekend to isolate the cause, but it is definately a ground or firewire issue for me. Using the mouse (to scroll a window etc) will make the pitch of the hum rise.

[macleodgrant]

Originally Posted by jonnypowell

Yipp, that's exactly what I have to do, which would mean it's certainly a grounding issue and not driver related..
Maybe we should write to Apogee with a link to this thread?

they're aware of the unbalanced outs issue and i reckon they will release and updated version which will include balanced outs at a later stage but they said it was to do with the power requirements and it would drain a laptop batter faster

it's annoying but that's why i just ordered the ensemble, with balanced out this problem will be no more!

the Duet i guess is more a mobile unit but it's annoying to even have these issues with a professional device. i just stated in another thread that even the Mbox1 had balanced outs!

now i know that mastering engineers often run unbalanced studio because it sounds better but for that to work you really need to have a system wired correctly and very professionally to avoid grounding issues; never mind the knowledge you need to have to ensure your studio is properly grounded so you don't risk electric shock by snipping the sleeve off the wrong cable - yikes!

i like things simple!

[pedrodash]

Originally Posted by macleodgrant

it's annoying but that's why i just ordered the ensemble, with balanced out this problem will be no more

i like things simple!

i'm almost selling mine and doing that.

[pedrodash]

Originally Posted by embrionic

Hi pedrodash,

I just want to restate that you may be getting offers of help to two different types of problems (someone please correct me if I have misread this thread.)

If you are getting "glitching" from your DUET with nothing plugged into it, then it is likely that you have a driver issue and your audio hardware/device drivers are not set up correctly. That is a very different problem from a bad cable or the fact that the unblanced DUET may be little sensitive to certain setups... Can you enlighten us on what kind of system you have? software/computer etc?

Then we may be able to offer some other solutions that might work.

There does appear to be some occasional hum/interference issues that other DUET users have noted (including me), but it is starting to sound to me like you are experiencing something else.

As a fellow DUET owner I am happy to try and help but we need some more info. Is it only when playing music or anytime? Can you post an mp3 of the sound you are hearing, as recorded through your system?

hey, embrionic, thanks for your interest and thanks everyone who's trying to help here..
the problem that i'm having is this glitch/click that seems like a digital click, like when your running out of CPU or something like that (but that's not it). I guess it is not a sample rate or driver problem also, cause everything is working properly with a mbox and a m-audio interface with the same settings.
I'm posting a link with 3 audio clips that I just recorded in my bedroom: SM57, Sterling Audio ST77 and a Bass track.
nothing was plugged into the duet, except the Mic/Bass, everything was recorded only on channel 1. I already tried different cables, also.
You can hear the clicks that the Duet is making when I turn the Gain up and down with the two mics, but these clicks are not happening on channel 2.
And you'll here the clicks that I was talking about on the Bass and St77 tracks too, but they are not happening with the SM57.

here's the link:
4shared.com - online file sharing and storage - download Duet Audios.zip

IF anyone knows what is happening, please let me know..
thanks

[DISCERN]

Originally Posted by macleodgrant

they're aware of the unbalanced outs issue and i reckon they will release and updated version which will include balanced outs at a later stage but they said it was to do with the power requirements and it would drain a laptop batter faster

I am sorry, but this is nonsense if I have ever heard it. Unbalanced outputs are completely viable in pro audio design. IT IS NOT AN ISSUE. Unbalanced outputs appear in a lot of gear, and in some cases a lot of very expensive professional gear.

the Duet i guess is more a mobile unit but it's annoying to even have these issues with a professional device. i just stated in another thread that even the Mbox1 had balanced outs!

now i know that mastering engineers often run unbalanced studio because it sounds better but for that to work you really need to have a system wired correctly and very professionally to avoid grounding issues; never mind the knowledge you need to have to ensure your studio is properly grounded so you don't risk electric shock by snipping the sleeve off the wrong cable - yikes!

i like things simple!

Well for professional gear, one would assume professionals would be using it. Correct grounding and studio wiring really isn't rocket science or some kind of black art. It is extremely well documented. If you are either too lazy or ignorant to educate yourself on correct studio wiring, then I won't bother you... go nuts. But suggesting that this is the fault of a manufacturer is beyond arrogant.

Just to make it perfectly clear; if you are having grounding issues with the DUET, it is because of the way YOU have wired your equipment together. Not because apogee selected unbalanced connections for the unit.


Like you said:

but for that to work you really need to have a system wired correctly

Stop blaming the wrong people and learn how to wire your studio correctly.

[David Robinson]

Originally Posted by DISCERN

I am sorry, but this is nonsense if I have ever heard it. Unbalanced outputs are completely viable in pro audio design. IT IS NOT AN ISSUE. Unbalanced outputs appear in a lot of gear, and in some cases a lot of very expensive professional gear.





Well for professional gear, one would assume professionals would be using it. Correct grounding and studio wiring really isn't rocket science or some kind of black art. It is extremely well documented. If you are either too lazy or ignorant to educate yourself on correct studio wiring, then I won't bother you... go nuts. But suggesting that this is the fault of a manufacturer is beyond arrogant.

Just to make it perfectly clear; if you are having grounding issues with the DUET, it is because of the way YOU have wired your equipment together. Not because apogee selected unbalanced connections for the unit.


Like you said:




Stop blaming the wrong people and learn how to wire your studio correctly.

Hi there,

+1.
truer words will never be spoken!

ppl by gear and 5mins later they are experts (not).

[macleodgrant]

Originally Posted by DISCERN

I am sorry, but this is n