[sci.electronics] All kinds of questions about audio electronics

max@eros.uucp (Max Hauser) (07/23/88)

In article <88Jul21.105530edt.493@neat.ai.toronto.edu>, Louis Lin asks:

| I often heard about people talking about the 'classes' of amplifier, ie
| class A, class B, class AB, etc.  ...  Can some nice
| audiophile outthere tell me what they are and how they work?  Thx.

Class A is the best, class B is mediocre, and class AB is in-between.
This replaced the old prime/choice/good/commercial/utility grading system
in 1984 at the behest of the RIAA (and the acquiescence of the USDA).

(The preceding is facetious, but is MUCH more accurate than the run-of-the-
net response to be expected from the "authoritative" source of rec.audio).


In article <5347@cg-atla.UUCP>, (Erik Hjortshoj) deposes:

| I am ... interested in building CAR amplifiers.
| 
| The references given in this group are helpfull but I whant to know
| how much harder it is to make car amps.  Are they safe enough to 
| stick in the car?  Is the 12V (14V) power source a problem.  ...

You might ask on sci.electronics, where they just spent weeks discussing
how much power can be gotten through a speaker at 12 volts (not as good
as the endless discussion about skin effect on rec.audio last year -- 
almost pure, in the sense of devoid of fact -- but approaching it).  Or,
you might subscribe to the high-audio mailing list, which (at least for
the first couple hundred postings, before I unsubscribed) took for 
granted that all repeat all high-end audio equipment was built with
tubes (valves), and (or so it appeared) was owned by university students;
but that source would probably immediately advise an electromechanical
alternator to obtain the necessary 300V B+, and discussion would ensue 
from there.  These may plausibly be unsafe to stick in a car.

But seriously: rec.audio is not the place to get good advice on things of
this kind -- though it IS a place to get plenty of advice ...

Max Hauser / max@eros.berkeley.edu / ...{!decvax}!ucbvax!eros!max


"The thermonuclear ignition, if properly coupled to the bulk lithium
deuteride, will propagate as a wave front with incredible velocity, 
consuming the entire mass in some tens of nanoseconds.  It is likely 
that the complete detonation will have begun *and ended* before the outer
casing has yet ruptured."  -- shock-wave physicist, Deutsche Forschungs-
und Versuchsanstalt fuer Luft- und Raumfahrt e. V.  (DFVLR)