[jarnopp]

I and a couple other folks have had this issue (channel imbalance and distortion). Mine started after about 75 hours of burn in. So, if for nothing else but testing, I recommend the burn in period!

I emailed Cavalli support and Alex responded promptly and had me ship the amp back. He replaced the board and shipped it back (all between Christmas and New Years, so great service). I am burning it in now, and so far (36 hours in) still sounds great!

Support@CavalliAudio.com

Good luck!

 

[bearFNF]

If it's humming/buzzing from the balanced output, something is wrong. It should be dead quiet from balanced.
SE output may have some transformer like hum. IME and YMMV

@callizer, you might check to see if the line-out of the hugo is too high??

My PC > Hugo > Liquid Carbon (RCA input, balanced output) > LCD-X setup has very noticable distortion. What might be thr problem?

Power cable? Dirty AC power? RCA? Wrong volume setting?

I'm using line volume out on Hugo (press and hold xfeed button), then controlling the volume on Liquid Carbon.

This post might help: http://www.head-fi.org/t/702787/chord-hugo/7995#post_10847182

 

[coastal1]

tbh after all of these posts about the nightmare of the hum/buzz issue, i am not planing to burn it in at all!!!

i will plug and enjoy the amp all the way, and screw the burn in.

not gonna risk it what so ever. 

150 hours of continuous burn in is strongly recommended by the manual. Seems unlikely this would increase the risk. I'd rather any issues pop up sooner rather than later.

 

[yage]

I'd rather any issues pop up sooner rather than later.

 
IMO, this is the real reason for 'burn-in'...

 

[frankrondaniel]

My PC > Hugo > Liquid Carbon (RCA input, balanced output) > LCD-X setup has very noticable distortion. What might be thr problem?

Power cable? Dirty AC power? RCA? Wrong volume setting?

I'm using line volume out on Hugo (press and hold xfeed button), then controlling the volume on Liquid Carbon.

 
Try turning the volume down on the Hugo.  What they call line out on the Hugo can be a little much for other devices.  I usually turn it down a color or two.

 

[Shini44]

150 hours of continuous burn in is strongly recommended by the manual. Seems unlikely this would increase the risk. I'd rather any issues pop up sooner rather than later.

 

   
IMO, this is the real reason for 'burn-in'...

 
so you guys suggest that i burn it in for 150 continues hours before i even try it?  
 
to avoid future problems that might occur within the amp? 

 

[callizer]

I sent an email to Cavalli Audio explaining the problem. I'll just quote it here.
 

 Dear Dr Alex Cavalli,  
I'm writing this email as a follow up for my post on HeadFi (callizer). I'm going to write in detail about the problem, probably a bit too detailed. But believe me I have left out all the unnecessary parts.
 
BACKSTORY
 
A friend of mine visited Jakarta during the holiday season from Singapore. He said "hey check out this Cavalli Liquid Carbon, it's pretty amazing". He used his LCD-3F and my LCD-X to showcase the amp. It was a trance song so there was a lot of bass. My mind was blown by the midrange presentation and bass impact. I immediately opened the Cavalli website only to find out that it's sold out. Bummer.
The amp used for the demo is no #00142, plugged into AC power in my house. He used his HM901s player as a source.
 
HOW I GOT THE CARBON
 
It turns out his friend (let's call him Y) has an extra LC, so he's willing to sell one for me. However, Y and his LC are in Singapore, so he needs to send his unit to Jakarta. Since it's quite a hassle, we decided that I'll just take the unit #00142 and my friend will take Y's Liquid Carbon.
So my Liquid Carbon is the unit #00142 that I've tried before in my own house. I don't have the box and manual yet since my friend left it in Singapore. I'll get the manual next month.
 
THE PROBLEM
 
After I got the Carbon, I tried this setup at home:
 
PC (Foobar) -> Chord Hugo -> Liquid Carbon (RCA Input, Balanced Output) -> Audeze LCD-X.
 
LC's Cable: stock power cable that came from the box and a generic RCA cable.
 
Note: I press and hold the Crossfeed button like it was written Hugo manual to set up line volume output.
 
I tried several songs:
Bryan Adams - Heaven
Bryan Adams - Summer of 69
Colbie Caillat - Brighter than the Sun.
Coldplay - Viva La Vida
 
The first 2 songs don't have much bass since it's from an acoustic album. The third and fourth are modern songs so they have quite a lot of bass.
I didn't notice distortion in the first 2 songs, but I can hear a very audible distortion from 3rd and 4th song. I can hear it every time there is a drum kick.

I recorded the sound with my phone:
 
- Volume at around 10 o'clock (normal) : https://soundcloud.com/kevin-setiadi-990622185/10-oclock
 
- Volume at around 11 o'clock (distorted): https://soundcloud.com/kevin-setiadi-990622185/11-oclock
 
TRYING TO FIND THE ROOT OF THE PROBLEM.
 
I had a mini-meet with my friend and a Jaben store representative. I compared the LC with Bakoon HDA 5520, MassKobo 404, and Wagnus Epsylon S. These three amps are powered by batteries. Result: no distortion whatsoever on these amps.
Theory#1: Dirty AC power?
 
I also tried other sources like Onkyo DP-X1 and AK240SS. Every source that uses LC has distortion, so I concluded Source is not the problem.
 
I also tried some expensive RCA cables, no effect.
 
Then I tried some high impedance, non planar headphones -- Sennheiser HD800 and ATH R70x (all single ended). Result: very clean, no distortion.
 
Theory#2: Liquid Carbon does not have enough current to produce a great bass impact on a planar magnetic headphone. This is weird because the LC definitely has some punch when I tried it with HM901s.
 
Theory#3: Balanced output is problematic.
 
To test theory#3, I tried LCD-X with single ended cable. It still produces distortion and the sound becomes really dark. Is it normal to have such a difference between SE and balanced outputs? In any case, SE is as problematic as the balanced output.
 
So this is the problem and some theories I've come up with. I hope you can help me find the solution.

 

[yage]

   
 
so you guys suggest that i burn it in for 150 continues hours before i even try it?  
 
to avoid future problems that might occur within the amp? 

 
You don't have to burn it in without listening to it, but I bet that if the amp is going to develop any sort of problem it's most likely going to do so during the first 150 hrs of use.

 

[Shini44]

   
You don't have to burn it in without listening to it, but I bet that if the amp is going to develop any sort of problem it's most likely going to do so during the first 150 hrs of use.

will burn it in for a day at least. 

 

[ambrose1985]

i seem to have a slight channel imbalance issue, but i can't decipher if it's a the sound stage or a real channel imbalance... it seems that i hear alot of bass and mid range from the left side and vocals more from the right side...
 
hmmm. 

 

[swspiers]

i seem to have a slight channel imbalance issue, but i can't decipher if it's a the sound stage or a real channel imbalance... it seems that i hear alot of bass and mid range from the left side and vocals more from the right side...

hmmm. 

Across multiple songs/recordings?

 

[yage]

 
i seem to have a slight channel imbalance issue, but i can't decipher if it's a the sound stage or a real channel imbalance... it seems that i hear alot of bass and mid range from the left side and vocals more from the right side...
 
hmmm.

 
This might help - http://www.audiocheck.net/audiotests_stereo.php

 

[defbear]

I burned mine in for about 200 hours. So I lost track of days. It made the amp a little more open and a bit brighter. Perhaps a bit more low end. My amp made it through without issue. But I personally don't think it's needed. My amp sounded super right out of the box. Also Alex is having us burn them in to produce better sound. Not to weed out bad amps. Although getting them to fail early on is a side benefit. As far as Noise is concerned. When I have my single ended th900's plugged into the LC, I can hear some ambient hiss if I turn up the volume up past 2-3 o'clock. I'll try it balanced tonight and report back. But I have no channel imbalance nor distortions even at some stupid high volumes.

 

[novaca]

Quote:

 
Mine hum/buzz immediately out of the box...

 
Originally Posted by Shini44 /img/forum/go_quote.gif
 
one of the last 25 amps?

 
No, sn 00368
And another curiosity: when the volume is at zero, I can still hear the music quietly (especially with gain 3x)

 

[WNBC]

I had this same issue (489) and it went away after burn-in. Now dead quiet even with my source at full strength. That may be some evidence of a burn-in effect?

No, sn 00368
And another curiosity: when the volume is at zero, I can still hear the music quietly (especially with gain 3x)