[MorbidToaster]

While I love my LF and expect it to come out on top over the Leben I'm still thinking about getting the Leben. 
 
I need a nice integrated for speakers in my new place, and I figured why not get a nice head amp as well?
 
I could see it being a fun, syrupy flavor compared to the LF. Looking forward to getting mine.

 

[cacatalysis]

The review did not provide detailed information with respect to the tubes used in the Leben.  "Mullard NOS"? is that for both the pre and power tubes?  Not a good combo IMO.  Too much bloom not enough clarity.  The top choice for tube combo to my experience is CBS7729/Amperex EL84 d-getter.  If you could not land a pair of 7729, use RCA red command 5751.  Leben is a highly transparent amp, different tubes will give you sound ranging from "tubey" to "SS like".
 

 

[runeight]

Quote:

Like sachu said. Looks wise. But that was easy; my dishwasher looks better than the LF. At least the LEDs are concealed. (Alex will probably stick a dead fish in my LL for all my LED bashing 

)

 
What I was planning to do was to wrap the LL with a string of Christmas lights and then glue them to the case. Make you wish you had your LF back.

 

[mwilson]

^ Macedonian, you heard the man. Kindly return the LF.

 

[nd4speed]

Quote:

The review did not provide detailed information with respect to the tubes used in the Leben.  "Mullard NOS"? is that for both the pre and power tubes?  Not a good combo IMO.  Too much bloom not enough clarity.  The top choice for tube combo to my experience is CBS7729/Amperex EL84 d-getter.  If you could not land a pair of 7729, use RCA red command 5751.  Leben is a highly transparent amp, different tubes will give you sound ranging from "tubey" to "SS like".
 

+1 This amp is very responsive to tube rolling.
 
 
Quote:

While I love my LF and expect it to come out on top over the Leben I'm still thinking about getting the Leben.

How would you know that, you never even heard it???

 

[obzilla]

Quote:

The review did not provide detailed information with respect to the tubes used in the Leben.  "Mullard NOS"? is that for both the pre and power tubes?  Not a good combo IMO.  Too much bloom not enough clarity.  The top choice for tube combo to my experience is CBS7729/Amperex EL84 d-getter.  If you could not land a pair of 7729, use RCA red command 5751.  Leben is a highly transparent amp, different tubes will give you sound ranging from "tubey" to "SS like".
 

 
To be fair, he doesn't have the top choice tubes in his LF either. He compared what he had. 

 

[MorbidToaster]

+1 This amp is very responsive to tube rolling.


How would you know that, you never even heard it??? :blink:

I have heard it actually. Alongside an LF in fact. The LF was a prototype and it was at a meet though.

I thought the LF out performed it then but it's been awhile so I didn't say absolutely. I expect the LF would win out though (like before). Either way I want one fot speakers and a different headphone flavor.

 

[Spaniard]

Apologies for not being more specific: Leben tubes are Mullard EL84 6BQ5 1955, British made; pre tubes are Raytheon 5751 black plates 3 mica and original Sovtek 12AX7. Although the initial idea was to use Mullards + Raytheon, I ended up using mainly the Mullards with the Sovtek 12AX7 as the Raytheons increased the buzz issues. I also used Genalex Gold Lion EL84s for a while until I got the Mullards, but the comparison was made with the Mullards.
 
Choice of tubes was made based on comments on different forums about what works better with the Leben. I am not a tube expert, and would not pretend to have used the best tube combination for the Leben; on the other hand, I am comparing a Leben with upgraded tubes vs the LF with stock tubes. Also, while there were differences between the different tubes, my impressions on the overall character of the Leben based on the tubes I used remain the same.
 

 

[Spaniard]

Quote:

Originally posted by MacedonianHero
 
The JJ stock tubes were ok with the amp, but it did improve quite a bit with the Genalex Gold Lions. I do have a matched quad of Mullard E88CC coming in next week.

 
Here we go again ....
I ... will .... resist ... the temptation .... to start .... tube rolling

 

[MacedonianHero]

Quote:

^ Macedonian, you heard the man. Kindly return the LF.

 
Never...its mine! LoL.

 
Quote:

 
Here we go again ....
I ... will .... resist ... the temptation .... to start .... tube rolling

 
Sorry, but I really think with the LF, upgrading from the JJs is a must. You're leaving a lot of cards on the table with the stock tubes.

 

[cacatalysis]

Quote:

Apologies for not being more specific: Leben tubes are Mullard EL84 6BQ5 1955, British made; pre tubes are Raytheon 5751 black plates 3 mica and original Sovtek 12AX7. Although the initial idea was to use Mullards + Raytheon, I ended up using mainly the Mullards with the Sovtek 12AX7 as the Raytheons increased the buzz issues. I also used Genalex Gold Lion EL84s for a while until I got the Mullards, but the comparison was made with the Mullards.
 
Choice of tubes was made based on comments on different forums about what works better with the Leben. I am not a tube expert, and would not pretend to have used the best tube combination for the Leben; on the other hand, I am comparing a Leben with upgraded tubes vs the LF with stock tubes. Also, while there were differences between the different tubes, my impressions on the overall character of the Leben based on the tubes I used remain the same.
 

I think for tube amps responsive to tube rolling, experience with one set of tubes should be viewed with precaution.  Ideally, one should compare two tube amps after extensive tube rolling with both.  In reality that is difficult to do.  To my ears, Mullards EL84s give you lose but more base.  To some that is good and others not good at all.  I also notice that using base enhancement on Leben is not a good idea for headphones.  With Leben and HD800, there is "tiny" hiss, but to me it is no big deal.  That being said one advantage of CBS7729 is how quite they are.  They are made for precision laboratory use (very low noise required), hence great for Leben driving HD800.  For EL84s, I prefer Amperex and Sylvania over Mullard by a big margin (driving HD800).  I stick with Amperex D-getters as powertubes.  I have never heard of LF so far, no comments on LF.     

 

[zardon]

The Leben CS300X is very responsive to tube rolling. Sadly some of the good EL84's are relatively expensive compared to other families - a good set of excellent condition NOS mullard EL84's are very hard to get, and if you can find a matched QUAD you would be looking at £300 or so. It really is an amplifier that is worth hearing. I think it is an exceptional performer, especially with 92db+ sn speakers.
 
With the Sony R10 headphones it delivers such a warm, inviting and enjoyable sound, even if some of the really expensive headphone amplifiers will technically outperform it.
 

 

[cacatalysis]

I have talked to people at Leben and very experienced headfiers who used Leben for long time.  I am assured you need four similar EL84s, but matching quad is absolutely necessary.  You do not even need matched pairs.  It has auto-bias, you can even use four tubes of different brands if you like.  For 12ax7/5751, a matching pair is also not required. 

 

[zardon]

Quote:

I have talked to people at Leben and very experienced headfiers who used Leben for long time.  I am assured you need four similar EL84s, but matching quad is absolutely necessary.  You do not even need matched pairs.  It has auto-bias, you can even use four tubes of different brands if you like.  For 12ax7/5751, a matching pair is also not required. 
 

I take it you mean, 'not necessary'?
 
I am sure you can get away with using unmatched tubes in the amplifier, most of them have auto biasing. I have been using tube amplifiers for 20 years however and always find if you give the amplifier the least work in regards to biasing, it always sounds better. Always best getting the matching as close as possible. Its not that difficult. I would argue about mixing brands and using 4 different tubes in a quad configuration. Every tube has a different sound characteristic. Thats why we roll them in the first place.
 
Incidentally who did you speak with in Leben? ive chatted with the owner Hyodo a few times and he is a tube fanatic who hand picks all his tubes (met him once at an event too and had a long chat - my own tube collection of over 1,300 tubes is small compared to his), I can't imagine he would ever condone using four different brand EL84s at the same time in the CS300(X)

 

[cacatalysis]

[size=medium]Here is an e-mail exchange between me and Mr. Yoshi Hontani at Leben:[/size]
 
[size=medium](my question to Yoshi Hontani at Leben)[/size]
[size=medium]One thing that concerns me is that most tube dealers really do not do a caerful job in matching tubes.? They just measured gains, and pick two measured similar and then claim that they are matched.? With new issue tubes, this is naturally not a big problem.  On the other hand, for NOS tubes it is a huge problem.  I am glad to hear the powertubes are self biasing.[/size]
[size=medium] [/size]
[size=medium](answer from Yoshi Hontani at Leben)[/size]
[size=medium]The  output tubes(EL84) are not necessary to be a matched quad due to a self-biasing circuit.[/size]
 
[size=medium]I would love to know how do you make sure your tubes are truly matched, pair or quad.  Recently, during a process to aquire some extremely rare NOS tubes, Osram PX25 and MP Pedersen U4E8 (a PX25 compatible), I also learned the issue of "dynamic match" for two tubes.  From my experience, getting truly matched tubes for rare tubes are not so practical, if not impossible.  I would love to get "truly matched" tubes, but the more expensive the tubes are the less likely a matched pair (let alone a quad) could be found, as I am getting a couple of amps without audo-biasing.[/size]
 
[size=medium]I talked to Jim Nicholls (JWN amp builder) about this issue again recently.  He has deisgned his own circuit and built more than 1000 tube amps (mostly for speakers).  He told me practially the same thing as Yoshi Hontani told me.   [/size]