60 Cycle Hum in Outboard. Help please.

[lolzgreg]

Hey everyone. It's been a while

I must admit, I'm a bit new to the game of outboard.

I'm getting noticeable 60 cycle hum from my outboard, but it's not particularly loud. I just feel like it *shouldn't* be there.

Anyone who has a lot of experience with this stuff, please advise. I am very appreciative

Has anyone run into grounding issues while using multiple A/D D/A converters and rack gear?

Here are some samples of the noise and lack thereof:

No Outboard:
http://dl.dropbox.com/u/63792534/No Outboard.wav

Unit 1 Outboard:
http://dl.dropbox.com/u/63792534/Unit 1 Outboard.wav

Unit 2 Outboard:
http://dl.dropbox.com/u/63792534/Unit 2 Outboard.wav

Unit 1+2 Outboard:
http://dl.dropbox.com/u/63792534/Unit 1+2 Outboard.wav

UPDATE:

The problem runs deeper than my outboard; I have a similar noise, only in the left channel, stemming from my preamps as well. If I use any "Left Input" on my Fireface, I am hearing this noise.

However, when I have no external devices turned on, there is no hint of this noise.

Here are audio clips:

Left Input: http://dl.dropbox.com/u/63792534/Preamp L.wav
Right Input: http://dl.dropbox.com/u/63792534/Preamp R.wav

Holy hell, someone tell me what's going on

ANOTHER UPDATE

It was a ground loop. I used two Ebtech Hum Eliminator XLRs in the signal path, and this was the result:

http://dl.dropbox.com/u/63792534/CLARIPHONIC HUM X XLR L+R.wav

Near dead silent, i.e., quiet enough for my tastes.

So, you ground-cutting gurus, can this ground issue be eliminated with cutting the ground on the cables?

If so, which end, the one going to the unit, or the one coming from the converter?

Also, on which cable: the input cable or the output cable?

I suppose the worst case scenario is I'm going to need to buy two 8 channel hum-8 rackmounts and put all my gear through there... that seems a little unnecessary...

Any other advice.

Thanks again everyone.

 

[amarshism]

Error 509

 

[lolzgreg]

Links are working now, thanks

 

[-Noodles-]

Is your studio power from a star configuration?
Can you isolate the equipment (piece or pieces) that are causing problem?

 

[lolzgreg]

All of my audio equipment goes to a Power Regenerator and to one outlet, so yes, everything is star configured.

When I run the piece of hardware solo'd without anything else plugged into the converter, it is still making noise.

Cheers.

 

[lolzgreg]

Bump for working links

 

[JeffTD]

Does this happen when the units are un-racked and separated from each other?

 

[lolzgreg]

Does this happen when the units are un-racked and separated from each other?

Yessir. I separated them with books and took them out of the rack. I also had only one unit plugged in at a time and one unit connected at a time via TRS cable; however, the noise was still present.

How goes it, Jeff?

 

[Platinum Samples]

a) Is there a grounding pin on the AC plug?
b) Are you using balanced or unbalanced cables to and from the device?
c) What's your I/O device?
d) Are you using a patch bay?
e) If balanced cables is the ground wired at both ends?

Rail

 

[lolzgreg]

a) Yes, there are ground pins on all of the AC plugs of the units in question.
b) I am using balanced cables. There is an unbalanced/balanced switch on one of the two units; however, flipping that switch has no influence on the noise.
c) I am using an RME ADI-8 Pro for my conversion, which is hooked up via ADAT to my RME Fireface 800.
d) I am not using a patch bay
e) As far as I know, the grounds are wired at both ends. I purchased the cables from Lava Cable, and they were made there.

Thanks so much for your help so far.

 

[ahjteam]

Do you get the same hum in other rooms in the house as well, like if the unit is in the performance room?

 

[lolzgreg]

No, I'm only getting the hum with these two units. I have never experienced a problem like this with gear, so I'm assuming it's inherent to the gear.

 

[tempe]

I'd say that something in the unit itself isn't grounded, or one of the components is on the way out. A visit to the tech might be in order. What gear is it exactly?

 

[Ermz]

Are the units 1176s, or something else of a vintage design? A lot of these units inherently let hum into the signal path. I battle with it on my 1176s all the time - generally gating the noises whenever I can. Only difference being it's 50Hz here.

 

[lolzgreg]

They're Kush audio units. In this case the Clariphonic and the Fatso, but they're brand new. I think I'm going to check with the distributor; perhaps they're defective. Again, thanks everyone for the help.

 

[Eduardo Apolonia]

I was going to suggest several things but most of them are covered by other suggestions.
I have the same problem with a Mohog Compressor but in my case when I have most of the other gear turned off it isn't so loud. In my case the compressor has a problem.

Have you tried connecting it to a different outlet and replacing the position of a unit that is working without any hum.
ex: Disconnect a compressor/EQ that doesn't have this behavior and connect the one that makes the Hum to the exact same cables.

And you can also try connecting another piece of gear to the exact same cables as where the noisy unit is now.

For me these tests will indicate if the unit has a problem or not.

 

[Platinum Samples]

Try:

a) Using an AC ground lift

b) Reversing polarity of the power cable (if possible)

c) Measure AC voltage between chassis to ensure you don't have a voltage differential and to avoid electrocution

d) Cut the ground on the XLR at the device side (for a balanced cable) -- you can buy XLR ground lifts which do this

All the above can sometimes help (individually or combined).

Rail

 

[lolzgreg]

Hmm... I just realized the character of the noise is different on each channel. On the right side, the noise is more of a hum/buzz, while on the left side it's more hissy and ugly sounding... what the hell could cause this?

 

[lolzgreg]

UPDATE:

The problem runs deeper than my outboard; I have a similar noise, only in the left channel, stemming from my preamps as well. If I use any "Left Input" on my Fireface, I am hearing this noise.

However, when I have no external devices turned on, there is no hint of this noise.

Here are audio clips:

Left Input: http://dl.dropbox.com/u/63792534/Preamp L.wav
Right Input: http://dl.dropbox.com/u/63792534/Preamp R.wav

Holy hell, someone tell me what's going on

 

[PhilTheBeard]

UPDATE:

The problem runs deeper than my outboard; I have a similar noise, only in the left channel, stemming from my preamps as well. If I use any "Left Input" on my Fireface, I am hearing this noise.

However, when I have no external devices turned on, there is no hint of this noise.

Here are audio clips:

Left Input: http://dl.dropbox.com/u/63792534/Preamp L.wav
Right Input: http://dl.dropbox.com/u/63792534/Preamp R.wav

Holy hell, someone tell me what's going on

YOUR SHIT IS POSSESSED BY THE DEVIL!!!!