The Leben CS300XS Thread

[cydest]

Hi,
 
I was doing some cable rolling on my system and removed the speakers cable from my Leben CS300x (yeah, the Mullard-one

) to plug the cables to another amplifier. Then I switched the Leben on for a while to warm it up....but forgot to plug the speaker cables again.... what an @#$^$% (repeated 1000x)
 
I left the Leben for approx. 60-90 min without the speaker cables plugged back. Positively there was no signal going to the Leben.
 

• Should I expect any damages to the trafos or any other parts?
• Any damage on the tubes?
• Does the Leben has a protective circuit when no load is applied?

 
Please reassure-me (or make fun of me), I had too much sleepless nights already

 

[ardilla]

Well, does it work? I think tubes are what gets the damage. Sometimes it doesn't matter anyway.

 

[Skylab]

If it works, you're probably fine. It's not a good idea to leave a transformer coupled amp unloaded, but with no input signal, likely you are OK. If you are worried, pop the cover off and look at the output transformers. If they don't look burned, and the amp works fine, I wouldn't be too concerned.

 

[tyberiusz]

Hallo All! This is my first post on this forum. Im wondering if RedBull is right on the sound change after switching output impedance, and my conclusion is that when you look at the schematic from post 1295, you can see it's dependant on the impedance switch, after that it passes a voltage divider and goes to headphone socket. Can anybody confirm ?

 

[mrtim6]

Im currently waiting for a new fuse Furutech from eBay also - I will report back once installed

 

[mrtim6]

Hi all I recently bought Fostex TH900 just trying them out now with the Leben - very impressed with this headphone - anyone else tried this combo? Bit early for impressions. I think Skylab mentioned in one of his posts the Dennon D7000 had an excellent synergy with the Leben. As the two headphones share similar DNA - would love to hear from anyone else.

Skylab wonder if you have had the opportunity to listen to the Fostex TH900 with your Leben?

 

[Skylab]

No, can't say that I have had that chance. But the Leben does seem to love the low impedance Japanese closed cans

 

[Dr. Roberts]

Quote:

No, can't say that I have had that chance. But the Leben does seem to love the low impedance Japanese closed cans

 
While the W3k does have good synergy soundwise using the Leben CS-600, this listener has always heard a soft buzz with no music playing which is annoying to say the least. Using the headphone output with the low impedance HE-6, dead silent background with terrific SQ. With the EAR HP4, lovely synergy with no background noise listening to the AT's.

 

[ardilla]

Sensitivity matters A LOT more than impedance with regard to buzz. The HE6 being the most insensitive headphone in production, it is a logical implication that any amp that would buzz with the HE6 would be useless..

 

[WizardKnight]

I saw this thread on the net about modding a Leben. I thought it might interest some of you.
http://www.audioaficionado.org/mbl-dcs-goldmund-etc/8875-leben-cs300xs-mutant-version.html

Also read another article on the net were someone had a custom leben ordered from the factory with better tubes, resisters, switches and then modded it more by changing out the coupling capacitors with the new V-Cap CuTF, etc.

http://www.highfidelity.pl/@main-135&lang=en

 

[Dr. Roberts]

Quote:

Sensitivity matters A LOT more than impedance with regard to buzz.

 
This is what Jonathan of Tone Imports (distributor of Leben gear in the U.S.) wrote....."Depending on the headphone impedance and sensitivity, it is possible to hear some low level hum........"
 
An unfortunate reality which is why this listener uses the Leben primarily with loudspeakers as opposed to cans. No hum whatsoever with the Harbeth 40.1's (6 ohms.....85db) 

 

[Skylab]

Yup. That's exactly right. I cannot hear ANY hum with the LCD-3, which makes the Leben and LCD-3 a very nice pairing. I also hear very little hum from the ATW3000ANV, which is surprising guen their high sensitivity.

I'm not sure I have ever owned a tube headphone amp that had absolutely zero audible hum with every headphone.

 

[ardilla]

Mine hums a bit ( the 50 Hz humming) with the HD650 but not at all with Audezes or HE-500
 
I have the "high power headphone output"-version (checked directly with Leben). If anyone wnat to know the resistor values I've posted this back in the thread.
 
(edit) Here's my previous post about this:  http://www.head-fi.org/t/415214/the-leben-cs300xs-thread/1290#post_8731184
 
All newer items are sold with lower-power outputs as standard (different resistors) - and so it will probably not hum. But I guess you lose a bit of headroom. But you can get the "high power" output by choice. But wether it hums or not depends a loton the AC quality as well, and might depend on what AC voltage is in your wall. I'm gonna try a DC-filter (Isol8 Axis)

 

[dminches]

High powered output?  I don't know if I would even want that (maybe my version already has it) since I never turn my volume control past 10 o'clock,  Usually it is barely at 9.

 

[Dr. Roberts]

Quote:

Yup. That's exactly right. I cannot hear ANY hum with the LCD-3, which makes the Leben and LCD-3 a very nice pairing. I also hear very little hum from the ATW3000ANV, which is surprising guen their high sensitivity.
I'm not sure I have ever owned a tube headphone amp that had absolutely zero audible hum with every headphone.

 
As I have stated previously, I also experience low level hum with the ATW3000ANV with the Leben. However, the synergy between the AT3k and the EAR HP4 is sublime!
 
I had been waiting for Audeze to get a handle on their QC issues before obtaining a pair of the LCD-3 and when I finally did place an order, no stock was available from my dealer so acquired a pair of the HE-6 instead.
 
Now waiting for the introduction of the Liquid Fire II to pair up with some Audeze's.
 
Skylab, you may very well have addressed this issue before in some other thread but which do you prefer, The LCD-3 with the Leben or with the Liquid Fire? Very good to know you hear no hum whatsoever with these cans plugged into your CS300XS.
 
Quote:

Mine hums a bit ( the 50 Hz humming) with the HD650 but not at all with Audezes or HE-500
 
I have the "high power headphone output"-version (checked directly with Leben). If anyone wnat to know the resistor values I've posted this back in the thread. 
 
All newer items are sold with lower-power outputs as standard (different resistors) - and so it will probably not hum. But I guess you lose a bit of headroom. But you can get the "high power" output by choice. But wether it hums or not depends a loton the AC quality as well, and might depend on what AC voltage is in your wall. I'm gonna try a DC-filter (Isol8 Axis)

 
My CS-600 was purchased new in April so it seems safe to assume it has the lower power output. All of my gear is powered by (2) PS Audio Power Plant Premiers which removes the quality of the AC power from the wall as well as voltage issues from the table. The tubes have been rolled using NOS RCA and Sylvania black plates although the hum issues were present with the stock valves as well.
 
Mine exhibits a low level hum with the HD650, a headphone that I still listen to on occasion since even though there has been incredible breakthroughs in hp technology since their introduction, these cans with the right source and amp, can still make for enjoyable listening. Currently I am using the SS Bakoon AMP-11R with them and they sound alive and exciting in comparison to the EAR HP4 using NOS RCA's.