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post #1771 of 2101

I don't have a website your best bet is to ask someone like Clayton sf about the SQ.

Do have a backlog of amps to build and wouldn't be able to build one to the end of the summer here soonest.

Right now I am building a 300B inter grated using a C3g drivers this is what Clayton has except he has mono blocks.

post #1772 of 2101
Quote:
Originally Posted by BugleBoy View Post

Tube rolling can be a rewarding experience....on some amps.

Don't know about CS600; but the CS300 can really shine with some good NOS tubes...it seems like a no brainer IMHO.

 

I do know the joys of tube rolling. I've done that on my Woo Audio headphone amps. However, the CS600 uses 6L6GC and EL34 tubes, 6CS7, and 6CJ3. I don't want to start to roll those types of tubes because they all seem either obscure (6CS7 and 6CJ3) or rare and expensive (6L6GC and EL34). I have a quad of Mullard EL34 tubes but I am going to use them when the stock ones die. A future investment.

post #1773 of 2101
Quote:
Originally Posted by BugleBoy View Post
Hey Glenn...how can I find out about your amps. Do you have as website?

Pardon my ignorance if it is common knowledge on Head-fi.

 

Here's the thread on Glenn's Amp.

Here are some photos of my current speaker setup. Glenn's 300B Mono Blocks.

Here are some other amps I own shown on my Flickr page.

post #1774 of 2101

As some of my previous posts were copied by ardilla, just a comment about the hum that disappeared after a resistor change. That is very hard to understand if the resistor was not already damaged by previous tube problems or something else. I don't say that that this apply in this case, but I have read post by users who roll tubes wildly, more by trial-and-error than checking if the tube is of appropriate type. Or can it be that a tube eventually has become defective and caused damage to the amplifier? That could explain the very divergent experiences of humming. Or is there a big variation in the tolerance for humming? If you compare with a SS amp and listen without music it is hard to avoid the conclusion that Leben has a slight hum. It is an old type of tube design. Is the humming a problem? I don't think so but I can only answer for me.

 

A tube can go bad anytime, but now I have a tube tester and this helps a lot in sorting out bad tubes. Tubes are seldom bad if you buy from reputable sources but this takes some time to learn and a tube tester gives additional security.

post #1775 of 2101
Quote:
Originally Posted by Clayton SF View Post

 

Here's the thread on Glenn's Amp.

Here are some photos of my current speaker setup. Glenn's 300B Mono Blocks.

Here are some other amps I own shown on my Flickr page.

 

Hey Clayton...thx for sharing all this info. Nice set-up you've got there. Looks great...and I'm sure sounds great too biggrin.gif

post #1776 of 2101
Quote:
Originally Posted by Anders View Post

As some of my previous posts were copied by ardilla, just a comment about the hum that disappeared after a resistor change. That is very hard to understand if the resistor was not already damaged by previous tube problems or something else. I don't say that that this apply in this case, but I have read post by users who roll tubes wildly, more by trial-and-error than checking if the tube is of appropriate type. Or can it be that a tube eventually has become defective and caused damage to the amplifier? That could explain the very divergent experiences of humming. Or is there a big variation in the tolerance for humming? If you compare with a SS amp and listen without music it is hard to avoid the conclusion that Leben has a slight hum. It is an old type of tube design. Is the humming a problem? I don't think so but I can only answer for me.

 

A tube can go bad anytime, but now I have a tube tester and this helps a lot in sorting out bad tubes. Tubes are seldom bad if you buy from reputable sources but this takes some time to learn and a tube tester gives additional security.


I agree that resistor may have been damaged in the past...and I had come to accept the hum as normal. But since i have replaced it I cannot hear any hum...even if I stick my ear to the speakers!

 

The conclusion I draw from this is the the 1K resistor can be damaged just enough to cause undesirable effects...and replacing it seems to cure the problem.

 

It'd be great if other CS-300 owners can post pics of this resistor in their amp...and better still check the resistance with a multimeter.


Edited by BugleBoy - 5/16/13 at 6:01am
post #1777 of 2101

BugleBoy, congratulations that your problem is solved. It is useful to know that hum problems can depend on a damaged resistor and can be a good idea to check for those who have disturbing hum. My resistors and other components had no visible damage when I looked last time, and I have no disturbing hum.

 

I don't think that the speaker test is exact and reliable as sensitivity vary much between speakers. Many users have reported hum problem with some headphones and no problem with others. Leben has changed the impedance of the headphone output, as I understand to reduce the problem with sensitive headphones. A problem it that there is great variation in headphone sensitivity and some seem to have got a problem with the low power headphone output and insensitive headphones. But overall the change was probably good as headphones have become increasingly sensitive.

 

CS300 is an old style speaker amplifier with an output power that is low for speakers and very high for headphones. It is not inherently noise free but should not normally hum with speakers. I quote the  Stereophile measurment: "The unweighted, wideband S/N ratio, taken with the input shorted and the volume at its maximum, was good rather than great, at 71dB ref.2.83V from both channels with all three output taps." It is not surprising that Leben not always work over all possible headphone and speaker sensitivities. The main problem with speakers should be that many are too hard to drive for a 12/15 W amplifier.

post #1778 of 2101
Quote:
Originally Posted by BugleBoy View Post


I agree that resistor may have been damaged in the past...and I had come to accept the hum as normal. But since i have replaced it I cannot hear any hum...even if I stick my ear to the speakers!

 

The conclusion I draw from this is the the 1K resistor can be damaged just enough to cause undesirable effects...and replacing it seems to cure the problem.

 

It'd be great if other CS-300 owners can post pics of this resistor in their amp...and better still check the resistance with a multimeter.


Or it was a cold solder joint, increased resistance caused a lot of heat which burned out the resistor.

post #1779 of 2101

Hello. I wanted to report my experience about hum.

 

My CS300XS is a 230V unit bought in Europe and used in Europe. It hums from day 1 with my HD600 but not audible with LCD2. Hum with HD600 is not annoying nor discernible once the music starts to play. Rolling tubes did not have any effect.

 

Some months ago I bought some HD800 and the hum was horrendous and I couldn't use them with the Leben.

 

Then, some weeks ago I bought some tube damper rings. Normal silicone rings, I paid less than 10USD for a bag of 10 in eBay. I bought them to control the bass because it was a bit too loose with the LCD2 for my taste. I discovered that as a side effect the tube dampers eliminated almost completely the hum with HD800, there is still some hum on the left side but nothing disturbing. I am discovering this combination HD800+Leben which works quite well actually.

 

Did anybody else have similar experiences reducing hum with tube dampers?

 

Thanks.

 

Arturo

post #1780 of 2101
Quote:
Originally Posted by arturo71 View Post

Hello. I wanted to report my experience about hum.

My CS300XS is a 230V unit bought in Europe and used in Europe. It hums from day 1 with my HD600 but not audible with LCD2. Hum with HD600 is not annoying nor discernible once the music starts to play. Rolling tubes did not have any effect.

Some months ago I bought some HD800 and the hum was horrendous and I couldn't use them with the Leben.

Then, some weeks ago I bought some tube damper rings. Normal silicone rings, I paid less than 10USD for a bag of 10 in eBay. I bought them to control the bass because it was a bit too loose with the LCD2 for my taste. I discovered that as a side effect the tube dampers eliminated almost completely the hum with HD800, there is still some hum on the left side but nothing disturbing. I am discovering this combination HD800+Leben which works quite well actually.

Did anybody else have similar experiences reducing hum with tube dampers?

Thanks.

Arturo

No experience with actual improvements, but i do have 2 dampers per tube on my power tubes right now. Found a bag I had of them while moving and figured why not.
post #1781 of 2101
Quote:
Originally Posted by arturo71 View Post

Hello. I wanted to report my experience about hum.

My CS300XS is a 230V unit bought in Europe and used in Europe. It hums from day 1 with my HD600 but not audible with LCD2. Hum with HD600 is not annoying nor discernible once the music starts to play. Rolling tubes did not have any effect.

Some months ago I bought some HD800 and the hum was horrendous and I couldn't use them with the Leben.

Then, some weeks ago I bought some tube damper rings. Normal silicone rings, I paid less than 10USD for a bag of 10 in eBay. I bought them to control the bass because it was a bit too loose with the LCD2 for my taste. I discovered that as a side effect the tube dampers eliminated almost completely the hum with HD800, there is still some hum on the left side but nothing disturbing. I am discovering this combination HD800+Leben which works quite well actually.

Did anybody else have similar experiences reducing hum with tube dampers?

Thanks.

Arturo

No experience with actual improvements, but i do have 2 dampers per tube on my power tubes right now. Found a bag I had of them while moving and figured why not.
post #1782 of 2101

I have positive experience of tube dampers but never have had that much hum. They usually have most effect on the input tubes. Herbie's Audiolab makes good tube dampers for most sizes of tubes. Sometimes the effect is negligible or even to the worse, as decreased airiness.

post #1783 of 2101
Quote:
Originally Posted by arturo71 View Post

Hello. I wanted to report my experience about hum.

My CS300XS is a 230V unit bought in Europe and used in Europe. It hums from day 1 with my HD600 but not audible with LCD2. Hum with HD600 is not annoying nor discernible once the music starts to play. Rolling tubes did not have any effect.

Some months ago I bought some HD800 and the hum was horrendous and I couldn't use them with the Leben.

Then, some weeks ago I bought some tube damper rings. Normal silicone rings, I paid less than 10USD for a bag of 10 in eBay. I bought them to control the bass because it was a bit too loose with the LCD2 for my taste. I discovered that as a side effect the tube dampers eliminated almost completely the hum with HD800, there is still some hum on the left side but nothing disturbing. I am discovering this combination HD800+Leben which works quite well actually.

Did anybody else have similar experiences reducing hum with tube dampers?

Thanks.

Arturo

Extremely interesting!

Do you have a link to those tube dampeners?
post #1784 of 2101
Quote:
Originally Posted by Anders View Post

I have positive experience of tube dampers but never have had that much hum. They usually have most effect on the input tubes. Herbie's Audiolab makes good tube dampers for most sizes of tubes. Sometimes the effect is negligible or even to the worse, as decreased airiness.

What type of tube dampenereners did make it worse, under which condition?
post #1785 of 2101
Quote:
Originally Posted by ardilla View Post


Extremely interesting!

Do you have a link to those tube dampeners?

This is what I bought, from this seller: http://www.ebay.com/itm/Tube-Damper-for-12AX7-12AU7-12AT7-12BH7-EL84-6922-10PC-/260759770623?pt=Vintage_Electronics_R2&hash=item3cb67e55ff

 

I guess at this price it doesn't cost much trying.

 

Arturo

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