[Dr. Roberts]

Quote:

For the HE-6, I almost exclusively use the mighty Pioneer SX-1980. It sounds phenomenal with the HE-6.  But no one would buy one of these monsters just for headphones, I think.  Mine does most of its duty driving speakers.
 
My main headphone rig these days is the Leben driving the ATH-W3000ANV.

 
Unfortunately, the dreaded hum is present when plugging the ATH-W3000ANV into my CS-600 because of the high sensitivity of that particular headphone. Fortunately, when plugged into the HP4, the pairing presents a slice of audio nirvana.
 
Regarding the use of resistors when amping the HE-6 from the taps. HiFi Man makes a power amp adaptor for the headphone. It's a black box consisting of resistors, loudspeaker terminals, and a balanced headphone output.

 

[tiberiuspv]

I have had a similar hum issue with CS600+HD800. In my case, it was a fixed level hum (i.e. not volume dependent), only on the right channel. Very low level, but enough to be distracting on very quiet passages and between tracks. My solution was to add an attenuator on the headphone output, which reduced the hum away to nothing while leaving plenty of dynamic headroom.
 
Easy to do if you can use a soldering iron: just 4 resistors inside a headphone extension cord, to get about 8-10 dB reduction without changing too much the impedance curve (and thus the response curve of the HD800). There is plenty of space inside the headphone jack of the extension cord to put the 4 resistors. The big advantage of doing it that way is that you have not modded any of the components, so you can revert to the non-modded behavior by just removing the extension cord. The resistor values for the attenuator bridge depend to some extent on the headphone impedance, and I chose mine (very roughly) to match the 300-600 Ohm impedance range of the HD800. The right values may be different for the ATH-W3000ANV.

 

[Dr. Roberts]

What a shame when one shells out the necessary amount of dough to purchase a Leben that so many users experience the low level hum. It should not be necessary to use mods in order to achieve a quiet background with headphones from an integrated amp with a headphone out jack. It's really disappointing and a poor reflection on the brand itself. The really maddening aspect of this is that the U.S. importer is well aware of the situation. Of course, the dealer I purchased my unit from never brought it up before he had my check. Come to think about it, he never brought it up afterwards either, I did.
 
When one does raise the issue with Tone Imports all one gets in the way of info is that the hum may be present depending on the impedance and the sensitivity of the headphone. No mention of a possible remedy is ever offered. Not exactly an ideal way to run a railroad!!!
 
This owner rues the day when the Leben will require service since my understanding is there is no U.S. service rep.

 

[Clayton SF]

Quote:

What a shame when one shells out the necessary amount of dough to purchase a Leben that so many users experience the low level hum. It should not be necessary to use mods in order to achieve a quiet background with headphones from an integrated amp with a headphone out jack. It's really disappointing and a poor reflection on the brand itself. The really maddening aspect of this is that the U.S. importer is well aware of the situation. Of course, the dealer I purchased my unit from never brought it up before he had my check. Come to think about it, he never brought it up afterwards either, I did.
 
When one does raise the issue with Tone Imports all one gets in the way of info is that the hum may be present depending on the impedance and the sensitivity of the headphone. No mention of a possible remedy is ever offered. Not exactly an ideal way to run a railroad!!! It
 
This owner rues the day when the Leben will require service since my understanding is there is no U.S. service rep.

My Leben CS600 is silent on all of my headphones. I don't own many but these are the ones that I own and used with no hum:
K701, D7000, DT990 600 ohms, HD650, DT770 Pro 32 ohms.
 
Also, I have nothing but praise for Matt Rotunda from Pitch Perfect Audio. I purchased my Leben from him last year and when I had an issue with static coming from the speakers (and strangely, not the headphones), he was going to have my unit looked at. That never happened because it turned out to be dirty tube pins which cleaned themselves when I swapped the left for the right and back again while trying to isolate the source of the static.

 

[Dr. Roberts]

Quote:

My Leben CS600 is silent on all of my headphones. I don't own many but these are the ones that I own and used with no hum:
K701, D7000, DT990 600 ohms, HD650, DT770 Pro 32 ohms.
 
Also, I have nothing but praise for Matt Rotunda from Pitch Perfect Audio. I purchased my Leben from him last year and when I had an issue with static coming from the speakers (and strangely, not the headphones), he was going to have my unit looked at. That never happened because it turned out to be dirty tube pins which cleaned themselves when I swapped the left for the right and back again while trying to isolate the source of the static.

 
You are one of the lucky ones Clayton! Read thoroughly through the various Head Fi threads and you will soon realize just how fortunate you are with your Leben.
 
FYI, the sensitivity of the can appears to be much more of a factor in producing the hum than the impedance of the headphone.

 

[MorbidToaster]

Any good dealer should be the only person you deal with when it comes to issues other your unit. If you have to go straight to th company or the importer something is wrong with a product like this.
 
That's one reason I've bought entirely new gear from a local dealer. I know that if there's a issue I can give it to him and it'll be taken care of. Hell my dealer will even loan me something in the turn around process. 
 
Quote:

 
You are one of the lucky ones Clayton! Read thoroughly through the various Head Fi threads and you will soon realize just how fortunate you are with your Leben.
 
FYI, the sensitivity of the can appears to be much more of a factor in producing the hum than the impedance of the headphone.

 

[Dr. Roberts]

Quote:

Any good dealer should be the only person you deal with when it comes to issues other your unit. If you have to go straight to th company or the importer something is wrong with a product like this.
 
That's one reason I've bought entirely new gear from a local dealer. I know that if there's a issue I can give it to him and it'll be taken care of. Hell my dealer will even loan me something in the turn around process. 

 
I deal with who you deal with. The unit arrived in a sealed factory carton and was purchased at full retail when I was living in El Paso. Brian is a nice guy and is helpful in areas that he is knowledgeable in but every question I have ever asked him regarding cans has been referred to Jonothan of Tone Imports. In other words, Brian is a speaker guy.
 
So does that mean that you agree with me that there is indeed something wrong with a number of the Lebens being sold in the U.S.A.?

 

[MorbidToaster]

Quote:

 
I deal with who you deal with. The unit arrived in a sealed factory carton and was purchased at full retail when I was living in El Paso. Brian is a nice guy and is helpful in areas that he is knowledgeable in but every question I have ever asked him regarding cans has been referred to Jonothan of Tone Imports. In other words, Brian is a speaker guy.
 
So does that mean that you agree with me that there is indeed something wrong with a number of the Lebens being sold in the U.S.A.?

 
Right, but I don't have to deal with the problem is my point. Also, Tone claims there are no different 'versions' on the HP out but there obviously are so you can't trust their answers either.
 
Considering my unit came with a faulty ground (only effected headphones) I'd agree with your statement. Now that it's working I'm happy though and I know Brian will handle it if there's another issue.

 

[tiberiuspv]

First, there extremely few integrated amps which have a TOTL headphone amp section. To be more precise, I don't know of any, but my knowledge is not encyclopedic... Speaker amp designers typically tune their products for speakers, and pay only moderate attention to headphones. Obviously for economic reasons (smaller market), but also for technical reasons (much more variety of headphone behavior in terms of impedance compared to speakers) and due to a lack of understanding of the headphone afficionado market. The CS600 is just an example of this tradeoff. It is definitely not marketed/sold as a headphone amp - although it performs very nicely with a very minor adjustment. As a speaker amp, I love it with my O/96 - spectacular and musical sound. I'm definitely with MorbidToaster on this... I fell in love the first time I heard this combo, the fact that I could add headphones to the mix was just a minor bonus. I do have some nervousness when I see people buy the CS300 (or its variants) just as a headphone amp. While it may work fine, it was not purpose-designed, and I think you can get more reliable results from more specialized (and very small) companies like EC, DNA, Woo, and others.
 
Second, as both Clayton SF and Dr Roberts mention, the hum level of the CS600 is highly headphone-dependent. For me, the HD800 has a very minimal hum, and the AKG K702 none whatsoever. I agree that it is mostly an issue of sensitivity. On sensitive speakers (the O/96 are 96dB/W @ 1m), you can actually hear it if you put your ear an inch away from the speaker. Obviously, the design was tuned to make the hum disappear around that sensitivity. I suspect the CS600 would not sound that great with super-high sensitivity horns which exceed 105 dB/W @ 1m. The HD800 sensitivity is just border-line for it (after ratioing based on the output transformer & series resistors). This is not a quality control issue (as far as I can tell), but a (not very well thought out) design choice.
 
Third, on the quality and maintenance side, I must have been lucky since I have had no problem whatsoever... Based on forum reports, it does seem that there have been some instances of quality control issues at Leben. This can happen to any company, and needs to be rectified. I suspect it is especially a problem for smaller companies which do hand assembly (point-to-point wiring is much harder to do right repeatably than soldering sand on a slab of FR14). This is where going through a reputable local dealer pays off, as MT mentions. First, it takes the practical problem off your hands. Second, it provides a better pressure mechanism on the manufacturer to fix issues: if there are too many problems, the dealers will bail out, then the importer. Direct consumer feedback is much harder to cope with for the manufacturer, especially given the language & cultural barriers. I have also been dealing with Matt Rotunda, and I have strong confidence that he will provide the right level of support.
 
Finally, don't take this as a partisan defense of Leben... Fanboy-ism is definitely not my style. Like all products, they have pluses and minuses. For the price, I think they provide very good value if that type of sound is what you're looking for (and you like the retro styling). For headphones, they provide very nice sound also, with some TLC required in certain cases. In the interest of full disclosure, I don't use the CS600 that often as a headphone amp, as most of my can listening time is on a Stax SR-009. The HD800 still gets about a day a week..

 

[MorbidToaster]

Man O/96 and CS600. Impressive to say the least. 
 
My dealer is getting some O/93s I'm looking forward to hearing soon.

 

[tiberiuspv]

Yes, O/96 and CS600 make a very nice combo. A bit above the budget I had initially planned, but OK since I do not change main equipment often. My previous setup (Bryston + Maggies) was over 20 years old, so very well amortized. Not to mention that my disposable income has increased substantially over those 20 years (that's one of the few advantages of getting older). While I could afford a significantly costlier setup, I think it would be far in the diminishing returns range - I tend to avoid splurging in excess...
 
The new setup is a radical departure from the old one, partially for aesthetic reasons. I love the Magneplanar sound, but the speakers just do not fit our new library/music room at all (much too tall and wide for the room) - a case of form trumping function

, not to mention spousal acceptance factor. My initial choice of the O/96 was driven by the size vs the audio reviews. I went to listen to them in SF and it was love at the first note... Matt Rotunda was using a CS600 to drive them, and I just bought the whole combo without trying any other amp - it just sounded right (I did bring a fairly wide sampling of my music). Luckily, I am getting the same sound at home (dealer auditions tend to be in a much better acoustic environment than home, which can lead to unpleasant surprises). This is most likely going to be my main speaker setup for a long time...
The headphone side is also jelling up (BHSE+SR009, HD800), I am just hesitating on getting a separate amp for the HD800, but will wait for the BHSE to be here and used for some time to see if I even need to move up from the Leben for the HD800.
The DAC side is still work in progress (no vinyl here).
 
This was almost a year ago and the O/93 were not out yet, so I have no comparison point. It will be interesting to get your feedback. From everything I have read, the Harbeth are no mean contender.
 
 

 

[MorbidToaster]

If you ever get antsy for another amp the Line Magnetic gear is fantastic with the Devore stuff I've heard.
 
As for a new amp for the HD800...I'd try to get a hold of a Cavalli Liquid Glass when you do (inevitably) want a new amp. Best I've heard the HD800.
 
I almost did the same thing you did with my system, too. I walked in, heard the system as a whole (including the turntable) and have bought almost the entire thing. I had to force myself to listen to other stuff 'just in case the Leben wasn't the best'. Ended up not being necessary.
 
Quote:

Yes, O/96 and CS600 make a very nice combo. A bit above the budget I had initially planned, but OK since I do not change main equipment often. My previous setup (Bryston + Maggies) was over 20 years old, so very well amortized. Not to mention that my disposable income has increased substantially over those 20 years (that's one of the few advantages of getting older). While I could afford a significantly costlier setup, I think it would be far in the diminishing returns range - I tend to avoid splurging in excess...
 
The new setup is a radical departure from the old one, partially for aesthetic reasons. I love the Magneplanar sound, but the speakers just do not fit our new library/music room at all (much too tall and wide for the room) - a case of form trumping function

, not to mention spousal acceptance factor. My initial choice of the O/96 was driven by the size vs the audio reviews. I went to listen to them in SF and it was love at the first note... Matt Rotunda was using a CS600 to drive them, and I just bought the whole combo without trying any other amp - it just sounded right (I did bring a fairly wide sampling of my music). Luckily, I am getting the same sound at home (dealer auditions tend to be in a much better acoustic environment than home, which can lead to unpleasant surprises). This is most likely going to be my main speaker setup for a long time...
The headphone side is also jelling up (BHSE+SR009, HD800), I am just hesitating on getting a separate amp for the HD800, but will wait for the BHSE to be here and used for some time to see if I even need to move up from the Leben for the HD800.
The DAC side is still work in progress (no vinyl here).
 
This was almost a year ago and the O/93 were not out yet, so I have no comparison point. It will be interesting to get your feedback. From everything I have read, the Harbeth are no mean contender.
 
 

 

[Dr. Roberts]

"Speaker amp designers typically tune their products for speakers, and pay only moderate attention to headphones. Obviously for economic reasons (smaller market), but also for technical reasons (much more variety of headphone behavior in terms of impedance compared to speakers) and due to a lack of understanding of the headphone aficionado market.The CS600 is just an example of this trade off. It is definitely not marketed/sold as a headphone amp - although it performs very nicely with a very minor adjustment."
 
An interesting post on a site devoted to said "headphone aficionados".
 
The fact is that there are many more audiophiles that listen to loudspeakers than those that listen to headphones. I did not purchase the CS-600 to listen to cans, very rarely plug a headphone into the output jack of the Leben, and have commented before that the CS-600 is a wonderful amp when paired with synergistic speakers, but this site is specific to headphone users and prospective buyers of Leben gear should know as many pertinent facts as they can before plunking down their hard-earned dollars. There are hundreds of comments on this site regarding the use of a Leben integrated and headphones, the vast majority being of a positive nature. There are also several posts commenting on the "low level hum" that is experienced by many. Some of those making such comments rule out the usage of a Leben as a headphone amplifier because to them, listening to headphones with the amp humming away in the background is unacceptable.
 
My question would be, if this so called fix is a "minor adjustment", why is it not performed at the factory before the unit is unleashed on an unsuspecting public? It is not a QC issue. The problem is well known, has existed for some time, and it remains unresolved.

 

[dminches]

Quote:

Originally Posted by Dr. Roberts /img/forum/go_quote.gif
 
There are also several posts commenting on the "low level hum" that is experienced by many. Some of those making such comments rule out the usage of a Leben as a headphone amplifier because to them, listening to headphones with the amp humming away in the background is unacceptable.
 
My question would be, if this so called fix is a "minor adjustment", why is it not performed at the factory before the unit is unleashed on an unsuspecting public? It is not a QC issue. The problem is well known, has existed for some time, and it remains unresolved.

 
My experience both with the amp and on this site is that the hum is not "experienced by many."  I don't think that comment is supportable by anything other than anecdotal evidence.
 
Honestly, I think you have grossly exaggerated the issues with this amp.  Every component has to be matched with other components.  For example, most OTL amps will hum with highly sensitive headphones.  That doesn't mean there is anything wrong with the amp.
 
I have owned the 300sx for several years now and I have yet to find another amp that matches its performance with the headphones I own.  And it does really well with my PSB speakers too.

 

[Skylab]

What drew me to the Leben in the first place is that the headphone out is drive off the same output transformer as speakers. In essence, except for the different impedance from the secondary winding, the headphone out and the speaker out of the Leben are identical.  
 
MANY dedicated tube headphone amps hum with low impedance high sensitivity headphones.  This isn't unusual.  I can only very barely hear any hum if I really strain to even with my ATW3000ANV, and that's with no music playing.  Hardly a big deal.
 
Lots of choices for headphones these days, something like either Leben probably makes the most sense for someone who will use it with speakers, but I still think its pretty special with headphones.