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The Leben CS300XS Thread - Page 68

post #1006 of 2234

Can't wait to try mine with a suitable pair of speakers too.

Originally Posted by shabta View Post

I primarily use the Leban with my HD800s. But I set up some Proac Tablettes in near field. Sweeeeeeeet!



post #1007 of 2234

The characteristics of the tubes in the Leben are more prominent on speakers than on headphones, in my experience. Allows me to adjust the sound easily with different tubes whenever I change power cables or interconnects on different parts of the system. An amazing tube amp.  


post #1008 of 2234

My Leben buzzes when I connect the HD800 and T1. I'm assured by many this is not normal. So should I try cleaning / re-seating the tubes? They're stock, not old or anything.


I've tried moving the amp around to make sure it's not interference buzz, but alas it's still there.


Edit: I should mention that these are the only headphones in my collection that buzz with the Leben. The HE-6 doesn't buzz. The LCD-2 doesn't. The Audio-Technicas don't buzz (which is odd since they buzz on just about ANYTHING save the Zana). There's nothing wrong with the headphones in question either, since they don't buzz on anything else. It's a bit perplexing.

Edited by MuppetFace - 11/30/11 at 12:10am
post #1009 of 2234

Aren't both those headphones high impedance as opposed to the LCD-2 and HE-6 which are low?  That seems like the common denominator.

post #1010 of 2234

The Sony Z1000 buzzes as well, so it's not just high impedance headphones.


Really, I'm just wondering what I should do to troubleshoot. I'm going to open the amp later and try re-seating the tubes. I may try some other tubes as well, in case one or some of them is/are bad.

post #1011 of 2234

I have just fitted rubber damping rings to the Sylvania/Baldwin 6BQ5 tubes, two each tube, which has reduced the hum considerably.


Have to say this amp gets better and better each time I listen to it, well recorded vocals just tickle my ears, a very engrossing experience.


It's what ya pays yer money for smily_headphones1.gif

post #1012 of 2234

I still having this channel imbalance, although small, but quite hmm, annoying.

My distributor (or service center) recommend me to change the volume pot.

I can choose the normal Alps or more expensive ones.


Do you think what his recommendation make sense?  if yes, could you recommend me a better volume pot for my Leben.

Anyone change your Leben volume pot?  is it going to be better?



post #1013 of 2234

Two new (well, old, and not in great shape) set of tubes arrived, and I have exactly

the same problems with them :(


Still a constant annoying hum in right channel, and a hiss that is affected by the

volume (feels pretty much like a hiss I should get if I connected a pair or really

sensitive HPs, not the LCD2), both sounds are detectable with speakers as well,

but I have to put my ear close to the tweeter to hear it.




I think the EL84 tube on the far left might be burning warmer than the others by the

way... thought it was down to the tube having more clear glass on the top (as I saw

it with the lid on), but it's the same with the other tubes, and that's a bit weird...

another guy in here seems to have had that problem, due to loose tube sockets.

Don't really feel like operating on an expensive piece of gear I just got :(




Going to have a word with the seller tomorrow, anyone has any suggestions for me?

post #1014 of 2234

I would either get the seller to agree to having the unit sent to Leben and repaired at his expense or return it to him for a full refund. 


post #1015 of 2234

After suffering with a humming Leben I tried the output tubes fitted with rubber damping rings. Initially my thoughts were positive but on extended listening I found that the hum was very little reduced and the sound seemed robbed of some life.


This morning I decided to clean all the tube pins with Caig Deoxit and after refitting I can happily report that I now have a dead silent Leben.


I highly recommend this to all Leben owners smile.gif

post #1016 of 2234

That's good news, and good advice for owners of ALL tube amps.  Clean those pins!

post #1017 of 2234


I guess this question have already been asked before here in this topic...

But, is it safe to keep the Leben on without any speakers connected and the front switch set to "headphones" position?

What is the main danger if the switch is briefly set to "speakers"?


post #1018 of 2234



Tried putting some resistors on the headphone output (idea from here: http://www.highfidelity.pl/@main-135&lang=en )

and it did help with my LCD-2 (but not the HD600), but instead of the buzz, I got massive distortions on loud levels :/


So... still no real progress, it's now going back to the importer, where they will have a look at it.

Not very hopeful though, apparently their opinion is that "tube amps always make some noise" ...



How many here have a 230V Leben, and if you do, do you have any problems with hum / hiss? Especially

interested about how it works with the LCD-2, but all my headphones had the problem with this amp...

post #1019 of 2234

Well, I have the 115V version, but I've always had hum/hiss with my HD800 and T1. It's faint, but there. Don't have the problem with the LCD-2 though.

post #1020 of 2234

MY 230V version had a very low-level hum. Didn't bother me.

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