Leben's owners request! What I found inside my Leben CS-300X limited.

Hi guys,

Several days ago, I wanted to open the under cover of my beloved Leben CS-300X limited edition. What I found was weird. I loose wire from the filtering section of the rectified AC to DC from the transformer, the power supply (I think, I'm not an expert). I will show you below two video samples of that so it's gonna be very clarified.

As you can see, one of the ELNA capacitors (the third one of the four counting from the left) has one lead unused. No electrical contact. And I think that's not good! The strange thing is that the amp has been working perfectly and sounds terrific with my Sennheiser HD800's.

Videos:

http://www.megavideo.com/?v=6ZKOL7U0

http://www.megavideo.com/?v=1PLPKFPM

There are some pics I have found on Google in which I can more or less see that green wire soldered to the left lead of the cap. Examples:

Anyway, I don't know for sure that I have to solder that wire to the lead. The pictures are not 100% of evidence. I expect that the different voltage ratings ( EU / USA) (230/240/120) have nothing to do with this regarding the design. I need your help by posting a good pic of this part before risk of blowing up my amp.

Thanks.

Hi starfish,

Yep, your case is clearly worse. I don't have any SQ issues nor imbalance with the potentiometer. Left and right channels are perfectly matched. Of course speakers through the binding posts sound wonderful as well. I even connected a pair of AKG K1000's, so no problem.

Yeah, I didn't run the amp again since my discover. When I found the loose connection, the wire was suspended in the air, no chassis touching or anything. It could have been terrible if the tinned wire had touched the chassis (ground) or something.

I think, not just for me but for you too that it's gonna be helpful if you open the bottom cover to see if you have a circuit issue around.

"I'm beginning to suspect QC is going down at Leben probably in part because the demand has gone up quickly on these amps. But I must say I'm greatly disappointed having spent $3,800 on an amp that is more or less unlistenable with its current issues."

Mine was built way before, it is a CS300X "limited" (There are even CS300X with no "limited" label, I don't know why). I've heard that Mr. Hyodo is running busy with a lot of demand. There are rumors about a realising of a 300B SET amp. He needs to discontinue one product to build the supposedly new model. I hope the CS600 as the non chosen one. I own the CS660P so I don't care.. hehe.

Looking forward to watching your pics. Thanks.

Quote:

Originally Posted by purrin 

Not good - a tinned floating wire (possibly with DC) that's almost touching the speaker output? I can't tell, but it looks like it may have been soldered on there at some point - just badly soldered on. It happens though on these types of amps.

No, that was not the case. When I opened it inside the wire had enough space between components, contacts and the chassis. The reason is that I touched the wire and bent it in order to see it better so that was far away from the speaker output prior to my discovery.

Quote:

Originally Posted by starfish 

Ok, I opened it up and snapped a photo.  The green wire is indeed soldered to that leg of the cap.  If you trace the green wire, the other end is connected to the blue cap immediately to the right, attached to its left leg at the tag strip.  I hope this helps!  It appears the blue cap to the right also has a wire connected to one of the speaker binding posts.  So, without seeing a schematic or taking a while to reverse trace the circuit, I can guess that maybe it has to do with impedance and could be why you don't hear anything out of the ordinary.  

 

Thanks for posting it. It is really really evident and obvious, isn't it? And yeah, the wire ends to the left lead of the fourth cap.

Quote:

Originally Posted by Clayton SF 

This is clearly a photo that I took of my amp. I bought my Leben CS-300XS on June 28, 2010 and it was delivered on August 5, 2010 if that helps give you a timeline on the Lebens out there. I also can't tell whether the soldering work is good or not.

 

Quote:

Originally Posted by Clayton SF 

 

I zoomed in on the green wire and cap-to-cap solder from another photo.

 

Good pics defenitely. What I don't understand is that your fourth cap doesn't seem to be soldered to a "black" wire as well where the green wire is soldered there too. You know, even there are different caps and resistors used with the timeline. If you search for pics inside this Leben model, you will find "blue" resistors with gold plated leads. Mines are brown, and Starfish's and yours are clear green/blue resistors. I will post some pics later to show you the differencies.

Quote:

Originally Posted by starfish 

I'll also add I noticed several poor quality solder joints inside my amp.  :(  I wish I hadn't looked, to be frank.  Any one of those could be a cold or partially cold joint causing the problems in my amp.  But I'm not touching a thing!  A new amp is on the way to my dealer so hopefully it will arrive soon.  I think Leben needs to find a competent technician in the U.S. to handle service and QC issues.  Their distribution is wide enough to warrant it.  Had I purchased the Cary amp I was comparing to this Leben, it could have been sent to Cary and back to me by now.  I'm not saying Cary makes a better amp or not... I really don't know.  But it does lend some credence to the idea that Leben needs a better service network than what is in place.

Ahh, you know? It's not just you, mine is the same. The soldering skills in Leben amps seem to be poor quality. My Leben CS660P, the same way. I don't get it. This is not a chinese amp, it is a proud japanese amp. Japan culture is exquisite and perfectionist. So sad.

Most probably the green wire in my case was a cold joint, yep.

These are supposedly the Leben ladies with those "great" skills:

I've seen easily quite better solder joints everywhere. The Leben's solder joints are probably the worst I've seen, so grainy and bad looking.

On the contrary, one of the best solder joints I've seen are from DECWARE by the way. Shiny, perfect shape, form and line (very well integrated in the joint).

I encourage every Leben's owner to post some pics inside their Lebens. Maybe someone could be shocked to see a similar issue like me.

Great pics. It's a pleasure to have a galery made by Apple. You are defenitely a Woo Audio fanboy, hehe. I will post some pics of mine later. There are some differences. I don't want to take and edit them right now because I cannot use my macintosh now, I'm using an ugly PC meanwhile.

I guess the XS version is similar to my X "limited" regarding the loose green wire. I'd like to see that wire in a pic of an "X" version.

You know, this is the absent black wire I mentioned before (this is in my Leben):

On the contrary, yours :

WTF?

Apart from that, you can attest that parallel yellow wire does just nothing, the other end has no contact to anything. This is in every amp. One of your pics shows it very clearly:

I'm gonna see where that black wire goes to. More to come. What I really need is a photo of another Leben with that common joint by the green and black wire to be 100% before warming the soldering iron. Any circuit change could make a mistake for my part and do what I should not do.

Quote:

Originally Posted by starfish 

I don't see an immediately obvious electrical purpose for the wire other than perhaps a test point, easy to find without having deep knowledge of the circuit?  I.e. Find the yellow wire and measure DC voltage at the floating end?  That's easy to understand for an apprentice in a QC role.

 

 

Otherwise, perhaps it is a mechanical joint done prior to mounting the blue cap, allowing an easier fitting without lateral movement of the tag strips, and done before that portion of the circuit is mounted to the amp?

Yep, that is what I thought at the end. Anyway, that yellow wire doesn't matter.
 

What matters is that absent black wire shown in Clayton's amp. Has your amp the black wire similar to my unit? :

This is currently the only pic I have for now. I have the task to post internal pics of my Leben but an issue of my Mac is pending to solve.

PD: My unit is 230V AC.