[agustinf]

In case it helps. In both my 300 and 600 I had some issues with noise, and after playing around with tubes they were mostly gone. However, it seems that cleaning connectors with Deoxit and most important (I believe the root cause of everything I was hearing that shouldn´t be there) the bass boost mechanism. I even went back to using the old tubes that I presumed faulty and they worked fine.

 

[Matro5]

In case it helps. In both my 300 and 600 I had some issues with noise, and after playing around with tubes they were mostly gone. However, it seems that cleaning connectors with Deoxit and most important (I believe the root cause of everything I was hearing that shouldn´t be there) the bass boost mechanism. I even went back to using the old tubes that I presumed faulty and they worked fine.

Thanks for this post. I have the slightest hum with my cs300sx in my new office while it was silent in the old space. So, I'm curious about your experience. I have tried a DC blocker but maybe the solution is Deoxit.

Can you describe the noise issues?

 

[agustinf]

Thanks for this post. I have the slightest hum with my cs300sx in my new office while it was silent in the old space. So, I'm curious about your experience. I have tried a DC blocker but maybe the solution is Deoxit.

Can you describe the noise issues?

In my case, it was about cracking and clipping, which is what I usually consider to be a tube issue (or a cable). That´s why I checked that first. Later as I noticed that operating switches and knobs brought their own share of cracking I got into cleaning what I could. That said, I believe it may not be relevant for hum as that can be related to transformers or ground issues. In your case, if this thing appeared when you moved to a new location, perhaps you may check for that. Try perhaps connecting all your electronics to a single point. That my help and it is an easy and cheap try. Report back!

 

[fr9ncisco]

In my case, it was about cracking and clipping, which is what I usually consider to be a tube issue (or a cable). That´s why I checked that first. Later as I noticed that operating switches and knobs brought their own share of cracking I got into cleaning what I could. That said, I believe it may not be relevant for hum as that can be related to transformers or ground issues. In your case, if this thing appeared when you moved to a new location, perhaps you may check for that. Try perhaps connecting all your electronics to a single point. That my help and it is an easy and cheap try. Report back!

Hello all,
Its is true that a tube needs to be well adjusted to its socket.
Some considerations at least may be of interest. When unplugging a tube, try to pull its straight from the socket instead of tilting it around to get it out, because it my damage the socket. People that do a lot of tube rolling may face this issue. I did not know this first and leben sockets are of vwry good quality. But after years using tubes and reading around about tube gear, its something I discovered.
The second thing, when heating up, tubes have a tendency to move inside the socket because of heat and metal dilatation. And it may does some cracking, not on the leben but on an audio research i own. So sometimes, when it is off, I push on tubes down to check they are in place rightly, and this has worked for me.
Another thing : tube gear seems to be sensitive to vibrations from speakers or else.
I used some rubber pads under the amp suuport feet with success to remove parasite vibrations.
And sometimes, a tube may be defective and generate hum and noise. Its a good idea to check tubes too.
My 2 cents.
Happy listenings

 

[kiling92]

Hello!
I need your advice
Last month I bought from a user a leben cs300xs;it sound fantastic.
Yesterday after moving the leben for clean the rack,when I connected it again to the electric current it not work properly anymore.i try to explain better
When I insert the 6.3 jack to the leben,when I insert for a half it sound powerful on the left channel and very very weak on the right channel;when the jack is totally insert the result is inverse;the left channel from my headphones become very weak and the right channel strong and powerful.
I tried to connect my headphones in a digital output and it work perfectly;so..the heapdone don’t have any issues.
I tried to sobstitute the valves and the problem remain.
Someone of you had fall in this experience before?thanks who will help me

 

[agustinf]

Hello!
I need your advice
Last month I bought from a user a leben cs300xs;it sound fantastic.
Yesterday after moving the leben for clean the rack,when I connected it again to the electric current it not work properly anymore.i try to explain better
When I insert the 6.3 jack to the leben,when I insert for a half it sound powerful on the left channel and very very weak on the right channel;when the jack is totally insert the result is inverse;the left channel from my headphones become very weak and the right channel strong and powerful.
I tried to connect my headphones in a digital output and it work perfectly;so..the heapdone don’t have any issues.
I tried to sobstitute the valves and the problem remain.
Someone of you had fall in this experience before?thanks who will help me

 

[agustinf]

Check knobs and switches, if you haven’t done so yet. Also, check your mains voltage to see if you’re near their 110v-115v ideal ratings).

 

[kiling92]

In the end it was a cable defect.
However this amp it’s very frustrating,it sound so good but It make heavy distortion with headphones.while with speaker is perfect.i use my Sony mdr R10 and At level 11 of the knob it star to make heavy distortion.why?i change valves more time but the issue is always here..

 

[agustinf]

On the other hand, this simply shouldn't be the case. The 300x should be perfectly silent if you manage to put the puzzle together (I don't have crazy sensitive IEMs, but I do have CIEMs and I don't hear a thing). Give it a chance and go around the different elements again, fresh tubes, clean power supply, clean knobs and switches, caps and parts not worn out, etc. Yes, it is a lot, like keeping up with a vintage car, but a perfectly silent 300x is possible in my opinion (and likewise with the 600, a superior amp in my book).

 

[ardilla]

In the end it was a cable defect.
However this amp it’s very frustrating,it sound so good but It make heavy distortion with headphones.while with speaker is perfect.i use my Sony mdr R10 and At level 11 of the knob it star to make heavy distortion.why?i change valves more time but the issue is always here..

It is a known issue that there is some hum with high impedance headphones for some users, but usually there is no problem with low impedance headphones

 

[kiling92]

It is a known issue that there is some hum with high impedance headphones for some users, but usually there is no problem with low impedance headphones

It’s not the usual hum,I properly feel heavy distortion on bass region and generally crackling sound.i assume this amp is properly made just for speaker,because with speaker it work perfectly

 

[ardilla]

It’s not the usual hum,I properly feel heavy distortion on bass region and generally crackling sound.i assume this amp is properly made just for speaker,because with speaker it work perfectly

Very strange. Have you tried other headphones?The headphones output is just the speaker outputs with a couple of resistors

 

[Matro5]

I have no hum with any headphones that I’ve tried. My amp is silent on speakers as well. I’m pretty sensitive to tube hum - and empathetic to those whose amps display it - but it is possible to have a dead quiet version of this amp

 

[kiling92]

However searching here through the three I red many comments about leben and the headphone distortion;I connect my leben to the pre phono,connect it to a Rega rp10;I unmounted all my chain and try every single device in another hifi chain;all them work perfectly,while for leben if I connect a dap the distortion is lower,but it is.for speaker sound perfect…I can’t find an answer to this

 

[ardilla]

I have no hum with any headphones that I’ve tried. My amp is silent on speakers as well. I’m pretty sensitive to tube hum - and empathetic to those whose amps display it - but it is possible to have a dead quiet version of this amp

My impression is that it depends on the region and the mains power. I might be wrong but it seems that Europeans, AC 230V, have more problems with hum than US users, 115V