Πρέπει να είσαι περισσότερο προσεκτικός, όπως εγώ
*. Το θέμα δεν είναι επιστημονικό -
στην επιστήμη η διάψευση είναι ευλογία. Είναι καθαρά κοινωνικό. Το να δίνεις δικαίωμα να σε πιάνει στο στόμα του ο κάθε
παρακατιανός δεν είναι θέμα εγωισμού - είναι
υπονομευτικό της συνόλης κοινωνίας. Διότι καταβαραθρώνει κάθε έννοια ιεραρχίας και σεβασμού στους ανωτέρους. Και όταν η καταβαράθρωση επισυμβεί στο ιδεολογικό/φαντασιακό πεδίο, αφεύκτως ακολουθεί και η καταβαράθρωση στο πραγματικό. Τις θλιβερές συνέπειες τις βιώνει η χώρα εν συνόλω τους τελευταίους μήνες. Ευτυχώς που οι ξένοι, άξιοι θεματοφύλακες των αρχαίων ελληνικών αξιών της αυτάρκειας, της περηφάνειας και της ευψυχίας, φιλοτιμούνται να μας τις θυμίσουν.
* "
To feedbacks opponents, a well-designed amplifier without feedback is preferable a similar amplifier with it. Presumably, this also includes individual devices like tubes or transistors. There is an important, though not obvious, exception that casts doubt on this view. The triode the favorite of audiophiles has built-in local negative feedback.
In a plate-follower triode gain stage, as the grid voltage (the input signal) increases, the plate current increases. This causes the plate voltage (the output signal) to drop. Since the plate current depends on the plate voltage, it will be lower than it would have been had the plate voltage remained constant. This, by definition, is degenerative, i.e., negative feedback: It could be eliminated by making the plate current independent of the plate voltage. This could be done inside the tube by adding a second grid, connected to a constant high voltage, between the control grid and plate. To keep the electrons that bounce off the plate and getting absorbed by the second grid, a third grid, connected to a low voltage, would have to be added between the second grid and the plate.
What would such a tube be called? A pentode, of course! With no negative feedback, its gain and output impedance are much higher and its linearity is poorer. The sound of the triode is almost universally preferred. Considered in this light, feedback shouldnt look so bad. For a tube amplifier to be called truly feedback-free in the local as well as the global sense it would have to be built entirely of pentodes. Any takers?"
http://www.normankoren.com/Audio/FeedbackFidelity2.html