[mandrake50]

I think you just answered my question. But to answer yours, Yes my Emotiva DAC one is now attached Both balanced and SE at the same time. If I remove the SE connection the SE input hums. This does compromise both the DAC and Amp in that SE inputs and outputs cannot be used with another piece of equipment.

I will give it a try, but I believe that simply adding a ground from the case or more likely back panel (chassis ground of some kind) of the amp and DAC would work as well. Saving the SE outputs and inputs.

 

[mandrake50]

Well I'll be a Blue Nosed Gopher! When I attach a RCA cable between the DAC and Amp the hum goes away. It only takes one cable but I attached both left and right. Unplug the RCA and the hum quickly fades in. Plug in the RCA and it fades out. For me at least this is a Work-Around. At the same time this is really Mickey Mouse. Is this a design flaw? Did the manufacturers forget to tack down a ground wire? And is that all the new power supply is? A little proper internal grounding? The ' RCA ground wire' did not seem to affect the sound adversely. Has anyone tried hooking up a 2nd DAC to the SE input vs grounding via RCA jacks to the balanced DAC? I did not have time to try that.
Great big Thank you for this work around.

I am glad that this worked for you. It is not ideal, but in my case it does the job. I don't have any situation where I need to use the SE outs on the DAC nor the inputs on the LC to connect other equipment.

 

[Peridot]

I will give it a try, but I believe that simply adding a ground from the case or more likely back panel (chassis ground of some kind) of the amp and DAC would work as well. Saving the SE outputs and inputs.

 
What the 'fix' is actually doing is grounding the SE input of the LC to the LC's own ground.
 
For some reason (deliberate or otherwise) the SE input on the LC is not grounded. By connecting both balanced and SE inputs to a source component which has a common ground for its balanced and SE outputs, the LC inputs are being connected to a common ground too (via a loop through the interconnect cables and the source component).
 
The same effect can be achieved by connecting the SE input ground on the LC to pin 1 of the balanced input XLRs, or to the amp's casing.
 
I don't know why the lack of a ground on the SE inputs is causing hum on the SE output even when the input is from the balanced connectors, but it is.

 

[rocketron]

Hi guys.
I have tonight tried the S/E output on my Carbon. Using Magnum V6 and Ortofon EQ-8.
No hum issue at all. The Carbon is connected to a Chord Hugo 3.5 to 3.5.
I also connected a Chord Mojo same result. No hum.
The only thing I get is a slight very slight channel imbalance at near 0 volume when i run a pair of HD800S
Balanced .
All I can say is it might be poor grounding on your house electric supply.
Saying that I do have a separate earth cable run too a out side earth spike from my hifi system.
I do hope you can get round the grounding issue with out having to send the amp back.

 

[defbear]

Did you mean the SE output hums? Cause if you remove the SE connection how can it hum?

On the LC I am feeding the balanced inputs from the balanced outputs on my Emotiva DAC. I then plug single ended Fostex TH900 into the SE input of the LC. On the front of the LC panel I have chosen to listen to the balanced inputs. I turn the amp to 11:00 and hear amp hum until the music starts. When the music ends the hum is readily apparent. NOW if I take a single RCA cable and run it between the DAC and the AMP the hum disappears.
That is how.

 

[Allanmarcus]

 

Did you mean the SE output hums? Cause if you remove the SE connection how can it hum?

On the LC I am feeding the balanced inputs from the balanced outputs on my Emotiva DAC. I then plug single ended Fostex TH900 into the SE input of the LC. On the front of the LC panel I have chosen to listen to the balanced inputs. I turn the amp to 11:00 and hear amp hum until the music starts. When the music ends the hum is readily apparent. NOW if I take a single RCA cable and run it between the DAC and the AMP the hum disappears.
That is how.

With just the balanced inputs connected to the inputs, can you try left, then right. Disconnect the unused cable from from both ends, then from just one end. Swap cables (left/right) and try that. See if the hum is or is not there for every once of those combinations. The issue might be the ground in one of the two cables, or in one of of the four jacks on the DAC/Amp.

 

[bearFNF]

On the LC I am feeding the balanced inputs from the balanced outputs on my Emotiva DAC. I then plug single ended Fostex TH900 into the SE input of the LC. On the front of the LC panel I have chosen to listen to the balanced inputs. I turn the amp to 11:00 and hear amp hum until the music starts. When the music ends the hum is readily apparent. NOW if I take a single RCA cable and run it between the DAC and the AMP the hum disappears.
That is how.

Um, why connect the headphones to the LC input? Wouldn't you want to use the output on the front?

 

[defbear]

I'm sorry but are you being serious right now?  You've been told directly that this potentially solves the issue, within the last week.  Many people with the same DAC have reported this issue and this fix.  Alex even wrote a big post about potential grounding issues way back last year before the amps even hit the streets.  This isn't news, dude.    

EDIT - A word

I get it. No one is allowed to say nay against the Liquid Carbon no matter what the issue. And oops! If I didn't get the word on this amateur work around last week, MY entire life is not centered on this bulletin board. Sheesh!

 

[Peridot]

With just the balanced inputs connected to the inputs, can you try left, then right. Disconnect the unused cable from from both ends, then from just one end. Swap cables (left/right) and try that. See if the hum is or is not there for every once of those combinations. The issue might be the ground in one of the two cables, or in one of of the four jacks on the DAC/Amp.

 
It's nothing to do with cables, a number of us have done extensive testing to show that it's in the amp.
 
If it was an interconnect issue it wouldn't have been fixed in the revision to the second build.
 
There does have to be a signal present on the balanced input. Disconnecting one of the cables will remove the hum on the respective channel. 

 

[Allanmarcus]

 

On the LC I am feeding the balanced inputs from the balanced outputs on my Emotiva DAC. I then plug single ended Fostex TH900 into the SE input of the LC. On the front of the LC panel I have chosen to listen to the balanced inputs. I turn the amp to 11:00 and hear amp hum until the music starts. When the music ends the hum is readily apparent. NOW if I take a single RCA cable and run it between the DAC and the AMP the hum disappears.
That is how.

Um, why connect the headphones to the LC input? Wouldn't you want to use the output on the front?

I think it was a mistake. I imagine he meant to say he plugged the 900 into the SE output. 

 

[Peridot]

I get it. No one is allowed to say nay against the Liquid Carbon no matter what the issue. And oops! If I didn't get the word on this amateur work around last week, MY entire life is not centered on this bulletin board. Sheesh!

 
To be fair, you have been making the biggest fuss over this issue and I'm also surprised that you weren't aware of the work around that mostly solves it.
 
I'm happy to experiment and help get to the bottom of the issue, as much out of curiosity as anything else. It's not a problem for me as I'm using the balanced output but if I was as bothered as you by it I'd have returned the amp to Cavalli long ago for a warranty repair.

 

[defbear]

Um, why connect the headphones to the LC input? Wouldn't you want to use the output on the front?

Ok perhaps I misspoke. I am plugging my phones into the 1/4 jak on the front.

 

[bearFNF]

Ok, unless you are being intentionally obtuse, which I think you are, I am plugging my phones into the 1/4 jak on the front.

right and you call that an input when it's an output that's what I've been trying to get at here. In several posts you've mixed up inputs and outputs which really makes things confusing for people that are trying to follow what you're trying to do. That's all I was trying to get at.

 

[defbear]

right and you call that an input when it's an output that's what I've been trying to get at here. In several posts you've mixed up inputs and outputs which really makes things confusing for people that are trying to follow what you're trying to do. That's all I was trying to get at.

You are correct. Thank you!

 

[defbear]

To be fair, you have been making the biggest fuss over this issue and I'm also surprised that you weren't aware of the work around that mostly solves it.

I'm happy to experiment and help get to the bottom of the issue, as much out of curiosity as anything else. It's not a problem for me as I'm using the balanced output but if I was as bothered as you by it I'd have returned the amp to Cavalli long ago for a warranty repair.

It wasn't an issue for me either until I started using the th900's. I am not going to re-terminate them and they will be the main phones I will use with the LC. And yes, Monday I am taking your advice and contacting Cavalli.