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Old 23rd February 2004, 04:49 PM   #31
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Quote:
Originally posted by millwood
then educate us - I don't take a particular stand on that.

We can make this place great if and only if we share our "truth" and ideas. Right?
Yes, we can.

But it seems some think what makes a great place is a handful of "gurus" ministering to a flock of unquestioning sycophants.

What I think is roaringly funny is that so far none of these "experts" have been able to make an unambiguous case that the CFP has substantially greater feedback than the Darlington.

se
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Old 23rd February 2004, 06:20 PM   #32
Eva is offline Eva  Spain
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In terms of current, I see no difference between CFP and darlington, since both topologies have the same current gain [beta1 * beta2] and in both cases there are only the internal current feedback artifacts present on bipolar transistors

Using voltage drive, I see the darlington as one local feedback loop whose output feeds another local feedback loop, and the CFP as a unique feedback loop with two devices inside

I think that CFPs are only useful when driven from a voltage source
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Old 23rd February 2004, 11:15 PM   #33
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Default Hey Millwood.....................

Why don't you try building something for a change..............and broadening your perspective, instead of trying to be a PITA.

Leave that to professional PITAs...............like me.

Jocko
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Old 23rd February 2004, 11:22 PM   #34
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Default Re: Hey Millwood.....................

Quote:
Originally posted by Jocko Homo
Why don't you try building something for a change..............and broadening your perspective, instead of trying to be a PITA.

Leave that to professional PITAs...............like me.

Jocko
because I am too afraid of being associated with professional PITAs like you, Jocko.

that would be pretty scary, wouldn't it?

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Old 24th February 2004, 12:01 AM   #35
AKSA is offline AKSA  Australia
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I'm real short of time at present, but I'd like to add this.

Any amp with interstage or global feedback sounds different to one without. CFPs sound very different to emitter followers. True story. Build and listen. It surely relates to correcting after the event; loop feedback creates a spray of high order artefacts. Using faster components, 'shorter' topologies and shorter paths will minimize this effect, and global feedback amps can be built which still sound good, though not the same as a feedback-less amplifier.

Steven, Pavel Dudek, and Charles' Hawksford output stages were a revelation to me. They look extremely elegant, and use non-reactive, current driven mechanisms to keep all outputs on. I like it a lot and will surely investigate it more.

Switchless Class AB also can be achieved with single ended push pull. I have done so successfully. However, there is much more H2 and H3 than the Hawksford approach, though there is no global or interstage feedback.

On visitations from luminaries, like Pavel, Terry, NP, JC, Charles, think about it. These guys will only cast their pearls if they are made to feel welcome, and not attacked for holding views which differ from convention, or even text book. Most here are interested in new audio technology; on a forum, these guys are where it comes from. People who attack Nelson in his forum are either misinformed or idiots, and most would not begrudge him due respect. It is difficult to reconcile equality with the unequal contribution he makes daily. Those who are reluctant to respect people who have dedicated a large portion of their lives to an area which for them is a mere interest or hobby are naive fools. Millwood, you raise the spectre of Animal Farm. An absurd and baleful comparison; this is not a totalitarian environment at all, and no-one lords it over any other simply because they know something another does not. Indeed, the status of many of the people here present is often deliberately shrouded in mystery. I conclude from this that this forum is probably that most unusual group - a secret, knowledge-driven democracy. If someone speaks with authority, listen attentively, you might even learn something, and you might, on reply, be able to teach them something too. If it is nonsense, you be the judge. Challenging each comment, particularly in a personal way, sets people on edge and they soon leave.

To be an effective judge, pay your dues, build the damn thing instead of tinkering idly with PSpice, and listen. It's about building, listening, and forming a subjective opinion of your own. The average audiophile is concerned ultimately with how it sounds, and this is one technology where good specs probably mean less than anywhere else. It is not about nursing hidden resentments that so and so might just be looking down his nose at you. That is your problem; not their problem.

Cheers,

Hugh
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Old 24th February 2004, 03:55 AM   #36
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The moon is made of green cheese. This is a fact.

If anyone thinks I'm wrong, the burden of proof is on you to demonstrate that my statement is false. To do this, you must construct a rocket ship, fly to the moon with it and sample the soil.

Sound reasonable?
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Old 24th February 2004, 04:10 AM   #37
AKSA is offline AKSA  Australia
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Very droll, Humphrey, very droll........

Cheers,

Hugh
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Old 24th February 2004, 04:16 AM   #38
andy_c is offline andy_c  United States
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Hi Hugh,

Who's Humphrey? I don't have a TV (except the 13" one I use to navigate my DVD-A player menus).
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Old 24th February 2004, 06:15 AM   #39
AKSA is offline AKSA  Australia
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Andy,

Sir Humphrey Appleby, head of Department for Minister Hacker, in
'Yes Minister', a British series from the eighties.

Brilliant limey humor, cynical, laconic, well mannered, *****y, incredibly clever. You'd like it, Squire.

Shows my age.....

Cheers,

Hugh
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Old 24th February 2004, 10:16 AM   #40
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Quote:
Originally posted by andy_c
The moon is made of green cheese. This is a fact.

If anyone thinks I'm wrong, the burden of proof is on you to demonstrate that my statement is false. To do this, you must construct a rocket ship, fly to the moon with it and sample the soil.

Sound reasonable?

I wish Nature or Journal of Finance would take that approach: it would then be soooooooo easy to publish in top journals.

maybe that's why the internet is so attractive to us arm-chair publishers,
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