Leben CS600X - Class AB or pure class A? [message #96413] |
Wed, 22 February 2023 07:23 ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
kasperbergholt
Messages: 44 Registered: August 2021 Location: Copenhagen, Denmark
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Baron |
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Hi clever people,
I'm in the process of reading a review of a Leben CS600X integrated amplifier.
In one passage it says:
"The amp runs in Class AB rather than pure Class A. During use, it gets fairly warm but not uncomfortably hot"
Is that so? I was of the impression that all of Leben's tube amplifiers ran in pure class A.
The full review can be read here:
Thanks in advance,
Kasper Bergholt
/ https://bergholt.net/blog
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Re: Leben CS600X - Class AB or pure class A? [message #96534 is a reply to message #96454] |
Sat, 18 March 2023 17:47 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
kasperbergholt
Messages: 44 Registered: August 2021 Location: Copenhagen, Denmark
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Baron |
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positron wrote on Wed, 01 March 2023 18:35kasperbergholt wrote on Wed, 01 March 2023 06:28Thank you very much for the reply, pos ![Smile](/forum/images/smiley_icons/icon_smile.gif)
Would it be safe to say that class a operation is up to the output tubes max rating, which would be around 8 watts for EL84 tubes?
Thanks again,
Kasper
Good question. Mullard's manual says probably true for PP, maybe higher
at max tube plate dissipation. About 5 watts output in PP triode mode.
In single ended pentode mode, about 5 watts output. In triode mode,
about 2.5 watts out at max plate dissipation.
Hope this helps Kasper.
pos
Yes, it does, thanks!
I ended up getting the prior model, the Leben CS-600 (no 'x'). It's stunning.
![https://bergholt.net/gastronomi/wp-content/uploads/leben-600.jpg](https://bergholt.net/gastronomi/wp-content/uploads/leben-600.jpg)
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Re: Leben CS600X - Class AB or pure class A? [message #96549 is a reply to message #96534] |
Thu, 23 March 2023 20:49 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
positron
Messages: 111 Registered: May 2020
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Viscount |
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kasperbergholt wrote on Sat, 18 March 2023 17:47positron wrote on Wed, 01 March 2023 18:35kasperbergholt wrote on Wed, 01 March 2023 06:28Thank you very much for the reply, pos ![Smile](/forum/images/smiley_icons/icon_smile.gif)
Would it be safe to say that class a operation is up to the output tubes max rating, which would be around 8 watts for EL84 tubes?
Thanks again,
Kasper
Good question. Mullard's manual says probably true for PP, maybe higher
at max tube plate dissipation. About 5 watts output in PP triode mode.
In single ended pentode mode, about 5 watts output. In triode mode,
about 2.5 watts out at max plate dissipation.
Hope this helps Kasper.
pos
Yes, it does, thanks!
I ended up getting the prior model, the Leben CS-600 (no 'x'). It's stunning.
![https://bergholt.net/gastronomi/wp-content/uploads/leben-600.jpg](https://bergholt.net/gastronomi/wp-content/uploads/leben-600.jpg)
Glad it worked out well for you Kasper. It is possible to obtain near perfect, if not perfect reproduction quality from a PP AB1 amplifier using non inductive speakers. With cone/reactive type speakers, one can tailor for near perfect quality sound, although somewhat time consuming.
All the best.
pos
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Re: Leben CS600X - Class AB or pure class A? [message #96578 is a reply to message #96551] |
Wed, 29 March 2023 11:43 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) |
positron
Messages: 111 Registered: May 2020
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Viscount |
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gofar99 wrote on Fri, 24 March 2023 21:56Hi, .....
Well designed class AB amps can sound really nice as well, but I have seen none without negative feedback that do so. IMO NFB alters the sound...in hard to define ways and is a cause for considerable consternation in the audio field. Lots of arguments on it. A SE amp can work either way...but then they are all class A.
I know what you mean. I have heard enough PP AB1 amps over the decades,
that very very few are truly accurate/natural.
That is why I have designed my own monoblock PP AB1 amps, in triode mode,
No global negative feedback. Took some 30 years R&D, but found them to
be superior to SETs (with their inherent problems), and nearly perfect via specialized listening tests.
(I am tempted to say perfect, that close.)
It can be quite superior. Sorry if I sound argumentative, don't mean to be.
pos
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