[Dave74]

  When I originally checked mine with no input cables attached, I'm sure it was completely quiet so I had put the noise issue down to my Emotiva DAC.
 
I've just checked it again however and I'm getting a different result. With no input cables attached and fairly sensitive headphones (TP51s) connected to the SE output, there's a constant low level 'drone' almost like an aircraft engine noise.
 
This is audible at all volume levels from zero upwards. At high volume levels (past 2 o'clock in x3, almost full volume in x1) there's a louder interference that is clearly 50Hz 'transformer' noise.
 
The noise is the same at both settings of the input switch.
 
The balanced output remains quiet in all circumstances.
 
It would be helpful if Cavalli could shed some light on what might be causing the interference in SE output mode.

The hum I get from the SE isn't there when I first turn the amp on.  It builds up after about 30-45 minutes of use. I have tried turning it off and then back on and the hum increases within a few seconds while the amp is still warm.  This is probably why I didn't notice it before break-in, as I had just tried my JVC IEM's for 1 song.  
 
My balanced output is quiet at well.

 

[Cardiiiii]

Pretty sure Alex said a hum or whatever is normal with sensitive IEMs from the SE output.

 

[CrispyWonton]

Pretty sure Alex said a hum or whatever is normal with sensitive IEMs from the SE output.

 
Yes, it has been mentioned in the past. But I don't believe anyone had mentioned at the time that what begins as a low hum increases in intensity with time. Since more LC owners are now coming back with the same findings, I'd like to find out if this is still considered normal.

 

[Peridot]

 
The hum I get from the SE isn't there when I first turn the amp on.  It builds up after about 30-45 minutes of use. 

 
That would explain why I didn't notice it the first time. The amp was started from cold then, but tonight it had been on for a few hours before I checked it.

 

[CrispyWonton]

   
That would explain why I didn't notice it the first time. The amp was started from cold then, but tonight it had been on for a few hours before I checked it.

 
I observe the level of hum to increase to a distracting level within 30-45 minutes of use, same as @Dave74

 

[CrispyWonton]

My apologies, everyone. I realize now these messages are more appropriate in the other thread ...

 

[coastal1]

We are both making speculative statements. So to keep this conversation relevant to LC, how about we change the question? I believe that you agree it will cost something more to add in 150 hours of pre burn in at manufacture. What are you willing to pay on top of $599 for pre burn in versus doing it yourself. I think that would be useful information for Cavalli to consider if it's feasible or not.

My vote would be under $50.

BTW the office build out cost is accurate since I just signed the invoice for it.

Okay, that's somewhat of a backtrack from your previous estimates.

I love my amp so wouldn't pay anything extra for burn in onsite. Burn in was supposed to improve the sound of the amp but it seems it's really just illuminating problems with amps, and it seems that the number of amps with problems is much larger than one would expect from a run of 500.

It certainly sounds like Cavalli is handing these problems in a professional manner, but also seems like a little more quality check on the frotnt end wouldve avoided amps getting sent back and less headaches on both ends

 

[doctorjazz]

He can't win...there was a furor here whenever someone had to wait a day longer to get their LC. Now, they rushed them out too quickly, didn't take long enough to burn them in before shipping, not enough time on quality control. Wonder if Alex will do this again...

 

[Cardiiiii]

I reckon the next batch of LCs will be made the same way his other amps are made.

 

[mscott58]

I reckon the next batch of LCs will be made the same way his other amps are made.

That's assuming he'd jump into the hornets nest again...

 

[XenHeadFi]

I love my amp so wouldn't pay anything extra for burn in onsite. Burn in was supposed to improve the sound of the amp but it seems it's really just illuminating problems with amps, and it seems that the number of amps with problems is much larger than one would expect from a run of 500.

It certainly sounds like Cavalli is handing these problems in a professional manner, but also seems like a little more quality check on the frotnt end wouldve avoided amps getting sent back and less headaches on both ends

 
I think for my amp, burn in helped show there was a problem with the volume pot earlier than if I had not burned it in. I was making good use of the pot, trying to understand at volumes on 3x and 1x gains were to my liking.
 
Also, I remember hearing a slight bit of noise only when sound was being played at hour 0. There was a harshness when sounds decayed or in quiet parts, like there was a high noise floor. This occurred on my first amp and on my repaired one. By the next day, the noise had disappeared and never returned to either amp. A new kind of noise appeared after burn in, due to a malfunction of the volume pot. I had expected the Carbon to sound perfect, like my other consumer electronics, but those usually do get a 24-hour burn-in to find premature failures.
 
As for the apparent high number of issues, that is a very common selection bias. People with problems are more likely to post than people who do not have any problems because people with problems are seeking advice.

 

[doctorjazz]

This is true...5 or 10 complaints seems like a lot on the thread, but isn't that much percentage wise...

 

[Dave74]

Okay, that's somewhat of a backtrack from your previous estimates.

I love my amp so wouldn't pay anything extra for burn in onsite. Burn in was supposed to improve the sound of the amp but it seems it's really just illuminating problems with amps, and it seems that the number of amps with problems is much larger than one would expect from a run of 500.

It certainly sounds like Cavalli is handing these problems in a professional manner, but also seems like a little more quality check on the frotnt end wouldve avoided amps getting sent back and less headaches on both ends

I burnt in my LC mostly through regular listening with my balanced HE-500. The rest of the time was without headphones plugged in.  I turned it off every night so everything would have a chance to properly cool down and warm back up, just like how I will be using it.  
 
Yes mine has a hum, but it does not really bother me as I can't hear it while music is playing on my Nighthawks, which are the only SE headphone I will probably be using with it.   
 
I still think doing a burn in was a good idea as I feel potential problems are more likely to show up when the amp is new.  Also,  I actually enjoy burning in new gear myself, it's part of the fun and excitement of getting new gear.
 
And yes, I am still am loving my LC and am very happy with my purchase

  

 

[coastal1]

That's assuming he'd jump into the hornets nest again...

A Cavalli portable amp was in the works with a naming contest and everything before the Carbons were shipped, surely the production run on the portable will be far greater than 500.

I love my amp and of course have no problem with a business running like a business (I.e., trying to make money), but let's not pretend that's it's something different

 

[jlbrach]

This is true...5 or 10 complaints seems like a lot on the thread, but isn't that much percentage wise...
 
actually it is a rather large number since there are only 500 units out there