Cavalli Audio Liquid Carbon

[spritzer]

I figured I'd start a topic on this where people can actually find info about the amp.  I'll quote Kevin's post from the DIY thread in below. 

As with so many other of these projects, curiosity got the better of me so I actually bought one of these amps.  It had gone back to Cavalli to be fixed so no claims possible that it was an early unit and the new ones aren't like this at all.  That is the usual Cavalli defense plus that we are doctoring the pics to show his crap in an unflattering light.  Well for some pics I'll link in Kevin's post now:

1 hour ago, kevin gilmore said:

so on yesterday this showed up

 

 

 

 

 

quoting alex...

"In a nutshell, the Liquid Carbon is a fully-discrete, fully-balanced, transportable solid-state headphone amplifier that is capable of driving all but the most demanding of headphones - delivering satisfying levels and offering superb driver control for exceptional detail and linearity."

lets run that thru fact check for a second.   yep...   "Liar Liar Pants on Fire"

fully balanced?  nope, not in the way that any truly differential amplifier would be. (like any of the super symmetry variants) and absolutely no common mode rejection.

fully-discrete?  nope not really, see the single ended to balanced converter in the schematic below

http://gilmore.chem.northwestern.edu/lc.pdf

so much fail in one package...

 

can the stax mafia do better, you betcha. board in progress now, will run up to +/-24V and bolt to a heatsink. So say a liquid gold clone for about $300 in parts.

people, why do you buy poorly built crap like this.  Buy Schiit, or Audio-GD  or many other high quality brands for a lot less money.

 

So let's discuss what is wrong with this thing.  First of all, it's not actually balanced, more a quad of single ended amps which have no reference to each other.  Similar to the Woo Wes in that sense.  It uses a quad opamp as a phase splitter to deliver a balanced signal to the four modules (there are two on the top of the board and another two on the bottom of the board).  That uncovers the first lie, this thing is indeed not fully discrete.  Now the second bit, it uses bog standard off the shelf Jfets for input devices for each module, one P- channel and one N-channel.  Now these are all made in a pick and place machine so there is no way to match these input fets which is crucial to good performance. 

Another issue is the low power and the bad choice of output devices.  The severely limit the performance of the amp and are driven so low that they barely tick over. 

Now we come to the power supply, what a steaming pile of shit that is.  To save a few cents Cavalli decided to clobber one of those together himself instead of just ordering one from the people who actually know how to do this.  I checked and a MeanWell PSU which fits these specs costs 18$ for a single unit, much less when you buy hundreds.  How fucking cheap can one manufacturer be? 

I can't wait to get this here so I can do a proper review of it, Head-fi style. 

Now we all know that this is just a baby Liquid Gold so I can only imagine how much that one must suck.  Never fear though as I will buy one of those so we'll see how horrible it really is. 

Edited June 25, 2016 by spritzer

[3x0]

One of my friends was eager to buy one second-hand at the $600+ they seem to be going for today. I'm feeling a bit relieved I steered him away...

 

Seems like a pretty bad sign that the amp self-destructs when you plug into both the single-ended and balanced outputs.

[purk]

It wasn't bad sounding but a properly designed amp such as the GS-1 with a Dynalo Plus module is much better sounding.  Agreed with the build quality though.  They sold 1000 units at an average price of $700. 

 

[spritzer]

That's a lot of units and I bet a lot of angry customers.  The original owner of this one was certainly glad to be rid of it.  One can never forget that about Head-fi, if you are a sponsor then you can have any and all negative posts about removed. 

[purk]

I was not happy with the unit because my original unit had the channel imbalanced issue as well as significant hum with lower impedance headphones with SE output.  Took them couple of times to fix it right.  It is functional now and I always think of getting rid of it....but the form factor is nice for work....but yes...I take the old Headroom Ultra Desktop (Last desktop Max from Headroom) over this amp.

[mattyice]

I have both the LC and GS-1 on loan from another member here. This is my reply to him when comparing the two amp...

"The GS-1 is the better sounding amp. Tone and staging are both appreciably better than the LC. GS-1 is "smoother" and more refined across the spectrum. Mids, on the GS-1 are exceptionally good. The LC is slightly U shaped in presentation. While this is fine with a headphone like the hd650 it's not fine with the hd800. I don't see myself using the LC much with the hd800. I really like how the GS-1 is voiced." 

[kevin gilmore]

6 hours ago, 3x0 said:

Seems like a pretty bad sign that the amp self-destructs when you plug into both the single-ended and balanced outputs.

look at the size (power ratings) of the .47 ohm source output resistors.

[spritzer]

Those will burn up in no time. 

3 hours ago, mattyice said:

I have both the LC and GS-1 on loan from another member here. This is my reply to him when comparing the two amp...

"The GS-1 is the better sounding amp. Tone and staging are both appreciably better than the LC. GS-1 is "smoother" and more refined across the spectrum. Mids, on the GS-1 are exceptionally good. The LC is slightly U shaped in presentation. While this is fine with a headphone like the hd650 it's not fine with the hd800. I don't see myself using the LC much with the hd800. I really like how the GS-1 is voiced." 

The LC isn't even linear up to 20kHz so I bet it has a very oddly shaped sound. 

[purk]

Glad you are enjoying the GS-1 experience Matt.

Edited June 25, 2016 by purk

[Dave R]

13 hours ago, spritzer said:

One can never forget that about Head-fi, if you are a sponsor then you can have any and all negative posts about removed. 

That's one of the reasons why I no longer sign in on HF, and haven't done so for sometime. I do occasionally look on that site though to see what crap's been written, also to have a laugh.

[kevin gilmore]

here are 2 more, which I had known about a while.  When you send something in to alex to repair, you probably don't get your unit back, just the outsides.

and whats inside

2/15/16 <?  and serial number 345

notice how much stuff has been replaced

and how you expect a quiet power supply with only 1 pair of inductors (and very small ones at that), one on each power supply

 

 

Edited June 26, 2016 by kevin gilmore

[spritzer]

Wow...just wow.  Gotta hand it to Cavalli for being devious little shits. 

[purk]

BTW, the earlier units (1- to SN# 500) do come with a life time warranty.  At least they can't be all bad right?  They do pay for shipping each way too.  

[kevin gilmore]

Singlepower had a 5 year warranty too.  

Now nothing currently made is anywhere near that bad, if cavalli is experiencing a return rate for repair of more than 2% he is in a world of hurt.

 

[spritzer]

IIRC Single Power had 7 year warranty and look where that got people... 

Just because Cavalli is stupid enough to claim a lifetime warranty of these things doesn't mean anything.  He will be replacing all those parts time and time again until they claim it is due to abuse and not covered by the warranty.  Story as old as time...

[purk]

Yup, that did remind me of Mikhail.  I think the 2% figure is low because there seem to be several people who have experienced problems with the Liquid Carbon.  Like I said, mine had to make two trips.  Many people don't seem to know any better and just accept the fact that SE issues are common because it was designed as a balanced amp.  

500 amps were sold out in less than 6 weeks btw.  That's a lot of money due immediately.  Took roughly about 6 months to deliver.   

Edited June 26, 2016 by purk

[spritzer]

Cheap and "balanced" will generate a lot of interest.  We also have the same situation with Cavalli as RSA back in the day, only positive gushing from idiotic noobs so people think it is the bee's knee's.  Anything negative is removed per the Head-fi protocol. 

Kevin did spend some time with it today and this is what he sent me: 

Quote

Wait till you hear this. Sounds like shit on every single headphone I have tried.

I don't get the love for this thing.

 

[wink]

 

1 hour ago, spritzer said:

Cheap and "balanced" will generate a lot of interest.  We also have the same situation with Cavalli as RSA back in the day, only positive gushing from idiotic noobs so people think it is the bee's knee's.  Anything negative is removed per the Head-fi protocol. 

Kevin did spend some time with it today and this is what he sent me: 

"Wait till you hear this. Sounds like shit on every single headphone I have tried."

Perhaps a set of bionic ears is indicated......   

Or, perhaps a transplant from a cephalopod...  

When you're deaf, everything sounds bettah......  

Or, best of all, don't insult you hearing by listening to anything with a Cavalli product....  

Edited June 27, 2016 by wink

[kevin gilmore]

so it helps to have it on the bench where you can monitor whats going on while you listen to it.

unloaded balanced (which would be a 804 ohm load due to the feedback resistors), 40 volts peak to peak. and its a hard clip, but thats ok. Now add a 50 ohm balanced load and the output voltage dips to under 20 volts peak to peak balanced. Turn on the other amplifier and do the same, and with both running, 17 volts peak to peak.  At which point everything, the output transistors, and everything else is getting pretty warm. A number of the surface mount transistors are running pretty close to their power limits.

The why is probably obvious, the power supply is sagging. Down to less than +/-12V and the rails ride the music (or test signals) Plus you loose almost 7 volts due to the Vgs of the output fets.

The liquid fire had a pretty crappy underpowered power supply too.

Which is why even on hd800 you can hear compression in the music. And audeze... ouch.  And he6 well don't even bother.

The singlepower SquarewaveXL did a much better job of sounding better  (till it burned up)

A decent amplifier can actually be built in a box this size. But its not easy. And every single input/output connector just takes away from valuable board space

Also makes you wonder how much better a liquid gold would sound with a real power supply. I should be able to take the goldreference power supply and get it to mount in the same holes.

 

edit: i should mention that tests were done at 115 VAC.  The switcher is likely to produce more power when run on 220V

Edited June 27, 2016 by kevin gilmore

[spritzer]

I think you did more analysis there than Cavalli has ever done for any of his products.  Designing with just a multimeter for the win!!

[stax fart]

Nice Crapalli amp, as always.

[purk]

4 hours ago, kevin gilmore said:

The singlepower SquarewaveXL did a much better job of sounding better  (till it burned up)

 

I had the same thought actually.  Those SquarewaveXL was pretty good sounding.

[spritzer]

The Liquid Carbon is finally here after some lovely USPS fuckups and well... it didn't disappoint.  From the first notes I just wondered how could anybody think this even passable?  It has that Cavalli sound, diffused, veiled, flat, boring, syrupy and with no extension at all.  I mean seriously, this sounds good to people?  There is no control over the drivers, it's all lost in a haze of distortion. 

As a fun comparison, I setup the ESP950 I got in the same shipment.  The Carbon plus HD650 is what, 50% more expensive than the ESP950 but even with the POS E.90 amp the Koss walks all over it.  We all know how good the HD650 can be so yeah... not brilliant. 

[HemiSam]

whoops....LOL.  What a fail and yet they manage to sell many.

I enjoyed my ESP950 while I owned it, but it just didn't scale enough for me once I tried it on the KGST and I needed more down low.  I do agree it's good value for money compared to many other options out there.

HS

[spritzer]

One thing I've learned from 15 years on HF, it's very easy to sell something to the masses based on hype alone.  Seen it too many times to count.  Then the stuff just disappears from view... 

As for the ESP950, they really need to be modified to work best.  The stock cable is gone and replaced with a Stax one (as the stock one is too short and I have a lot of Stax ones) and the damping in the back needs to be looked at.  I'm also testing some ESP950 earpads off ebay.  They are certainly a step up from the stock ones which are crappy as all hell.