The Leben CS300XS Thread
Aug 19, 2015 at 8:12 PM Post #2,176 of 2,299
I have not tried any of that, I might be getting a DC filter, I think, but mostly I don't bother since I have different amps for the high imp headphones. Local power does seem to vary on such things, I have only tried it three places in the same area of my home town, so I shouldn't generalize, I am under the pression that 230v users such as myself are more at risk for hum than 110v.



I added Audience Adept Response AR12 to my system couple of years ago...it made a big difference.

you can read up on it here: http://www.stereophile.com/powerlineaccessories/407aud/#UIVkyZcuG4ZTVIMc.97
hello BuggleBoy,the issue i am talking about in that case is that there are no garranty that the phase is not inverted with neutral(usually ground is right).in europe and in france especially its a known fact, wheras if you use on a power supply an inverted device, it messes the whole orher hifidevices. How do we deal with this? Well,we test one by one every device plugged on the shuko power supply, making sure other are disconnected. I use myself a cheap mesuring tool that signals with a light the issue when i take it close to the de device. Some other people use a electric meter to verify this point. Then i am able to spot if there is an inversion of phase and neutral and in that case using a tape,i mark the plug and turn it 180°and then move to next apparel that i plug on the power supply. Until they are all checked separately. Inverting a shuko plug is a breaze where as in the us you would have to recable...
I red some posts on a french audiophile forum that advised to do this check and in my case it helped a lot. Sound was less fuzzy, it gave more cohesion and aeryness.
It costed me 10 bucks or so for the price of this tool but i thought it was worth it. I'll look up this info tomorrow night and post the links and at best will try to translate it for the english only speaker.
 
Aug 20, 2015 at 8:49 AM Post #2,177 of 2,299
hello BuggleBoy,the issue i am talking about in that case is that there are no garranty that the phase is not inverted with neutral(usually ground is right).in europe and in france especially its a known fact, wheras if you use on a power supply an inverted device, it messes the whole orher hifidevices. How do we deal with this? Well,we test one by one every device plugged on the shuko power supply, making sure other are disconnected. I use myself a cheap mesuring tool that signals with a light the issue when i take it close to the de device. Some other people use a electric meter to verify this point. Then i am able to spot if there is an inversion of phase and neutral and in that case using a tape,i mark the plug and turn it 180°and then move to next apparel that i plug on the power supply. Until they are all checked separately. Inverting a shuko plug is a breaze where as in the us you would have to recable...
I red some posts on a french audiophile forum that advised to do this check and in my case it helped a lot. Sound was less fuzzy, it gave more cohesion and aeryness.
It costed me 10 bucks or so for the price of this tool but i thought it was worth it. I'll look up this info tomorrow night and post the links and at best will try to translate it for the english only speaker.

 
So you are saying that everything in your house must be check for polarity - or just the hifi-stuff?
 
Aug 20, 2015 at 9:46 AM Post #2,178 of 2,299
Just the hifi stuff and whatever is plugged with it from the same socket from the wall. I have a dedicated wall socket for my hifi equipment. The main improvment was heard when the leben was correctly plugged. To tell you the truth, even though the tool i used made it obvious for the leben, i could not tell dor the Cambridge audio cd player i use.
 
Aug 20, 2015 at 6:47 PM Post #2,179 of 2,299
As a Reminder,  and as a warning, please pay extra care to electricity handling. If you dont understand any of what was said, dont even try to bother, just enjoy your gear as you always had.In any case please use extra care, anytime, anywhere.
 
ok here it is :
 
Its a thread on a french forum where some people are dubious and some are convinced and some of them have tested the principle and experienced a difference like i did with the leben.
http://www.forum-audiophile.fr/conseils-aide/comment-etre-en-phase-electrique-t23756.html
 
 
The type of gear (electric plugs) we use here in France and some other countries too is very different of what is used in UK or US
With a Schuko plug you still have ground connection but you can invert phase and neutral connection...
 
Here is a picture of such thing :
http://www.worldstandards.eu/electricity/plugs-and-sockets/f/
 
So if we use the kind on power supply like this one : (Sorry for the link, i have no affiliation with this website whatsoever, I googled "multiprise shucko" on google.fr)
http://www.audiophonics.fr/multiprise-schuko-ports-qualite-professionnelle-cablee-120m-p-4533.html
 
 
then inversing phase and neutral is easy with this schucko system.
 
But it is not generally found in general shops except in audio shops most of the time, am sometime with prices that can be outrageous for supposedly high end stuff.
 
 
In the end , my point is that in some countries, full respect to phase and neutral is done correctly but in France it is not all the time and we need to make sure of this to get the best of our hifi equipment.
 
 
Here is a link in French(sorry no translation tonight) : That explain how to test for phase inversion with a multimeter on a Hifi device.
http://www.hifi-cables.com/Mise_en_phase_chaine.htm
 
In short, it explains how to detect if you hifi device is plugged correctly or not, how to detect it. As well
I did the summary though Google translate and i got that that to me makes sense but well, to English speakers it might not :D: e.g. "the mass" for "la masse" wich is very hard to translate as it has an electrical meaning
+++
With any hi-fi or home theater system to draw all the qualities, it is important to conduct a phasing of all devices. This procedure is relatively simple. It allows to minimize the (earth grounding?)mass of currents flowing in the connecting cables which disturb the transmission of the signals : digital or analog.
 
+++
 
 
Again, please be cautious and take care of yourself.
To Moderators : I let it to your own judgment to remove this post, if this is considering dangerous in any way.
 
Aug 20, 2015 at 8:43 PM Post #2,180 of 2,299
Just the hifi stuff and whatever is plugged with it from the same socket from the wall. I have a dedicated wall socket for my hifi equipment. The main improvment was heard when the leben was correctly plugged. To tell you the truth, even though the tool i used made it obvious for the leben, i could not tell dor the Cambridge audio cd player i use.

 
I have tried flipping the schuko for the Leben and other stuff, with no result. But never tried to get all right at the same time....
 
However - if I unplug everything else, and try plugging in the Leben both ways (with the schuko)I should hear a difference - if my hum issue is about polarity - rigt?
 
Also - you have a link to that tool you are using - or a similar one?
 
Aug 22, 2015 at 11:51 PM Post #2,181 of 2,299

The problem is the power/mains transformer is to close to the output transformers. They are picking up
the magnetic field from the power transformer there is no cure for this. Changing the power transformer
to a higher quality one not so easy.  
 
Aug 23, 2015 at 12:39 PM Post #2,182 of 2,299
@ardilla: you are right if yoy tried flipping the shucko without any effect on the hum, then polarity is not the issue i'am afraid.
I started to read this lebe thread few days ago from first pages and haven't read all of them yet 146 pages. I do remember in the first pages i red that someone got rid of hum by moving tubes right in their socket, while the amp if off of course :).because some of them got not plased right... maybe this could be that issue.
As off the tool i was talking about its called brennenstuhl, here is a link on a french web site with its reference
http://www.inkstore.fr/store/brennenstuhl-multitesteur-6s2-electronique-anthracite-p-122282.html?gclid=CNTU_4miyb0CFUTHtAodzFcAfA,
you might be able to find it elsewhere . One note is that when you use this tool to check polarity, you need to disconnect rca connectors from the apparel you are testing. Just get it close to the apparel with your finger on the top, if the leben is not in phase, it starts flashing about 20 centimeters from it. Always check one apparel diconnected from the others by unconnecting modulation cables between them.
 
Aug 24, 2015 at 9:43 AM Post #2,183 of 2,299
The 15w speaker outputs of Leben CS300XS area enough to drive the HE-6 fine?
 
Aug 24, 2015 at 7:14 PM Post #2,185 of 2,299
@ardilla: you are right if yoy tried flipping the shucko without any effect on the hum, then polarity is not the issue i'am afraid.
I started to read this lebe thread few days ago from first pages and haven't read all of them yet 146 pages. I do remember in the first pages i red that someone got rid of hum by moving tubes right in their socket, while the amp if off of course
smily_headphones1.gif
.because some of them got not plased right... maybe this could be that issue.
As off the tool i was talking about its called brennenstuhl, here is a link on a french web site with its reference
http://www.inkstore.fr/store/brennenstuhl-multitesteur-6s2-electronique-anthracite-p-122282.html?gclid=CNTU_4miyb0CFUTHtAodzFcAfA,
you might be able to find it elsewhere . One note is that when you use this tool to check polarity, you need to disconnect rca connectors from the apparel you are testing. Just get it close to the apparel with your finger on the top, if the leben is not in phase, it starts flashing about 20 centimeters from it. Always check one apparel diconnected from the others by unconnecting modulation cables between them.

Thanks - I'll be getting one of those - nice to have =)
 
Aug 24, 2015 at 7:17 PM Post #2,186 of 2,299
 
The problem is the power/mains transformer is to close to the output transformers. They are picking up
the magnetic field from the power transformer there is no cure for this. Changing the power transformer
to a higher quality one not so easy.  

You are probably right about that. The hum is stronger in the channel that has it's otput transformer closer to the main transformer. 
 
Here is a cure suggested by Kevin Gilmore... I have not gotten around to try it (yet), it requires some skills: 
http://www.head-fi.org/t/686511/magnetic-shielding-of-trafo-inside-leben-amp
 
Aug 25, 2015 at 6:34 PM Post #2,187 of 2,299
 
 
The problem is the power/mains transformer is to close to the output transformers. They are picking up
the magnetic field from the power transformer there is no cure for this. Changing the power transformer
to a higher quality one not so easy.  

You are probably right about that. The hum is stronger in the channel that has it's otput transformer closer to the main transformer. 
 
Here is a cure suggested by Kevin Gilmore... I have not gotten around to try it (yet), it requires some skills: 
http://www.head-fi.org/t/686511/magnetic-shielding-of-trafo-inside-leben-amp


I don't know if you are up to it. I would remove it and replace it with a high quality C core transformer like Lundahl.
This was a learning experience for me building amps I had hum that drove me nuts trying to get rid of.
I removed the rectifier no more DC power to the amp turned it on and still hum. So it was coming from the power transformer.
Now I use C core transformers hum is non existent now.  I am surprised this company hasn't learned this with
all the complaints. Especially with a expensive amp like this.  
 
Aug 26, 2015 at 6:01 AM Post #2,188 of 2,299
 
I don't know if you are up to it. I would remove it and replace it with a high quality C core transformer like Lundahl.
This was a learning experience for me building amps I had hum that drove me nuts trying to get rid of.
I removed the rectifier no more DC power to the amp turned it on and still hum. So it was coming from the power transformer.
Now I use C core transformers hum is non existent now.  I am surprised this company hasn't learned this with
all the complaints. Especially with a expensive amp like this.  

 
The reason they have not done anything about it is beacuse it only affects a high impedance headphones. I have never had a problem with speakers, even quite sensitive ones. And cost is a key, of course, since every expense at factory level is mutiplied manyfold moving through importers/distributors and dealers. The cheapest option for fixing this (except the one sugested by Kevin Gilmore) might just be to move the main trafo over to an external case.... 
 
Aug 26, 2015 at 12:02 PM Post #2,189 of 2,299
 
 
I don't know if you are up to it. I would remove it and replace it with a high quality C core transformer like Lundahl.
This was a learning experience for me building amps I had hum that drove me nuts trying to get rid of.
I removed the rectifier no more DC power to the amp turned it on and still hum. So it was coming from the power transformer.
Now I use C core transformers hum is non existent now.  I am surprised this company hasn't learned this with
all the complaints. Especially with a expensive amp like this.  

 
The reason they have not done anything about it is beacuse it only affects a high impedance headphones. I have never had a problem with speakers, even quite sensitive ones. And cost is a key, of course, since every expense at factory level is mutiplied manyfold moving through importers/distributors and dealers. The cheapest option for fixing this (except the one sugested by Kevin Gilmore) might just be to move the main trafo over to an external case.... 


Yes that is another option a external case but that would also be a pain to do
 
Aug 27, 2015 at 1:31 PM Post #2,190 of 2,299
   
The reason they have not done anything about it is beacuse it only affects a high impedance headphones. I have never had a problem with speakers, even quite sensitive ones. And cost is a key, of course, since every expense at factory level is mutiplied manyfold moving through importers/distributors and dealers. The cheapest option for fixing this (except the one sugested by Kevin Gilmore) might just be to move the main trafo over to an external case.... 


Well, it affects my speakers. I have dipoles with very efficient 8ohm speaker for midrange and treble and a pair of less sensitive 4 ohm speakers wired in parallel for the bass. The crossover has a separate bass amplifier to match to the more sensitive midrange speaker but I bypassed that and plugged the Leben directly into the speaker terminals, it hummed on idle. Worse when amplified. 
 

Users who are viewing this thread

Back
Top