From: andrew@alice.att.com (Andrew Hume)
Newsgroups: rec.audio
Subject: rec.audio FAQ (part 2)
Keywords: faq
Date: 22 Dec 92 18:23:11 GMT
Article-I.D.: alice.24468
Organization: AT&T Bell Laboratories, Murray Hill NJ


hi netters,

	bob neidorff is having news problems and so i am posting this for him.
there will be three parts.

	just a reminder, DON'T HIT 'R'!! reply to bob or rec.audio as
per the instructions below.

			andrew hume

-----------------------------------------------------------------

This is Part 2 of 3 parts of the faq for newsgroup rec.audio, dated 15 Dec 92.

11.0 CD Players, CDs, Turntables, and LPs

11.1 What should I listen for when evaluating a turntable or CD player?
	For tape decks and turntables, the major specific problems are caused
	by speed variations (wow and flutter).  A good specific check for this
	is Richard Strauss' 'Also Sprach Zarathustra' (also known as the theme
	from 2001), which has a long, low, sustained organ note which comes in
	well before the main theme starts, and is held through the entire first
	movement.  Concentrate on that, and make sure it doesn't wobble or
	warble.  There's also a good bit for that at the beginning of Pink
	Floyd's 'The Wall', but it doesn't go on as long and so means you've
	got less time to think about it.  Tape decks particularly are also
	prone to losing high-frequency notes, so pick something you like which
	has a lot of treble, and make sure it is clear.

	The sound of a turntable is entirely bound up in the kind of cartridge
	mounted on it.  Make sure to listen to a table with a catridge similar
	to what you're buying, and not one in a different price bracket.  

	For CD players, try some piano music.  See if the high notes sound
	tinny.  Also, try something which has some soft parts -- not the same
	as turning the volume down.  The distortion specification for CD
	players (as for other devices) is measured at a high output level, but 
	in fact in CD players (unlike others) it's actually likely to be worse 
	in soft passages of music.  This is purely a function of the arithmetic 
	involved.  Most classical orchestral recordings will contain a 
	suitable soft passage.  (Most rock music won't.)

	The distortion in a CD player, if you want to call it that, is a 
	function of the granulation noise, or time-delay pre-echo that can 
	come out of the filtering.  To listen for this, use material that is 
	rich in high-order harmonics.  Brass music is great for this.

11.2 Are some discs better than others?
	Some recordings are better than others.  Some artists are better than
	others.  Some recording engineers are better than others.  Some 
	microphones are better than others.  Some music is better than others.

	Ignoring the above, there is some difference between discs.  Some
	of the very earliest discs were badly made and deteriorated with time.
	The technical problems that caused those problems have been solved.
	They included ink from the top bleeding into the disc, separation of
	the disc into two thin halfs, and oxidation of the metal inside.
	Also, some discs were made which have aluminium going all the way to 
	the edge of the disk, so are more prone to oxidation

	Some "gold" discs are available which are advertised to have better
	life and quality than common "aluminum" discs.  These sell for an
	extra US $20 or more per disc over the cost of the same music
	on a common disc.  Studies have shown that there is an advantage to
	glass-encased, gold platters for archiving computer data that is not
	error tolerant and will need to be stored for many tens of years.  I
	have yet to see a similar comparison which justified any extra effort
	for storing audio recordings for 50 years.  Part of the reason for this
	is that audio recordings contain error correction codes.  Another reason
	is that audio recorders can effectively reconstruct badly damaged audio
	data, even if there is data completely missing.

	Some discs seem to have pinholes in the aluminum, which are visible when
	the disc is held up to a strong light.  However, these discs play fine
	and last very well, so the effect of these pinholes is probably nil.

	Some have performed studies counting errors on various discs with
	various players.  They found that, in general, the error count was 
	consistent from one player to another.  Also, in general, most discs 
	have a low, consistent error rate which is perfectly correctable using 
	the redundant data stored on the disc.  This study did find that one 
	group of discs had a higher error rate than all of the rest.  This 
	group was the promotional discs, also called "music samplers" given 
	away by music companies to introduce you to their family of artists 
	and performers.  Despite these higher error counts, these discs still 
	played fine.

	If there is no abusive handling involved, I have rarely heard of a
	disc that degraded with time.  Of the few that have existed, they
	tended to be from one of the bad batches mentioned earlier.

	There is no question that some discs are mastered better than others.
	Some are badly mixed.  Some are so badly recorded that there is 
	noticable clipping.  Some are made from damaged master recordings.
	CD technology is no guarantee of good music or of a good recording.

11.3 Are CDs better than LPs?
	Some excellent recordings are mastered digitally, and sound great on
	LPs.  This suggests that there is nothing inherently bad about digital.

	Some find that LPs sound better than CDs.  Advocates of LPs claim that
	the digital to analog (D/A) converter in home CD players isn't up to
	the quality of the information on the disc.  They also claim that the 
	analog electronics in a home CD player can be poor. 

	Some believe that CDs do not sound like LPs because the CD does not 
	have the frequency response errors, the distortion, or the stereo 
	separation problems of LPs.  

	In general, though, there are good and bad CD players, just as there
	are good and bad turntables, cartridges, and tone arms.  Any ultimate
	comparison would require ultimate equipment, which is unaffordable.
	In moderately priced systems, there will be some signal damage from
	the turntable system and some signal damage from the CD player.  

	LP lovers often learn the nuances of cartridge selection, record
	care, and even turnable and tonearm adjustment.  They have found that
	the turntable will sound different if the arm height is adjusted,
	if the cartridge angles are changed, and if the tonearm wire is
	moved.  CDs do not offer as many avenues for the home experimenter.

	However, Audio Amateur Magazine has published modification projects 
	for CD players; particularly for Magnavox 560 and similar European 
	players.  Audio Magazine has also published such articles.

11.4 What turntable should I buy?
	Despite improvements in motor technology, most great turntables use
	belt drive.  Rubber roller (idler) drive sounds the worst.

	Select a turntable with a very heavy platter for the least wow and
	flutter.  Give the platter a rap with your knuckle.  It should not
	"ring" like a cymbal. It should feel and sound dead.

	Also look for a turntable that has good isolation from base to stylus.
	With the amp on and the turntable selected, but with the turntable
	motor off, put an old record on the turntable, lower the stylus onto
	the record, and then tap the edge of the base.  Not too hard, you don't
	want to send the arm flying.  At worst, you should hear (through the
	speakers) a quick 'thump' followed by silence; if you're lucky, you'll
	hear nothing at all.  If the sound continues beyond a quick 'thump',
	the mechanical isolation is not great, and you might want to look at
	some other make.  To perform this test with some turntables, it will 
	be necessary to unplug the turntable power cord.

	If the turntable has a tonearm, try to evaluate the arm, too.  A good
	arm should be adjustable in height. A good arm should allow cartridge
	adjustments. A good arm should accommodate a wide range of cartridges.
	Despite this, some arms work better with high compliance cartridges,
	while others are at their best with low compliance.  Ask.

	The original AR Turntable was very well received when it was first
	made, and the current AR Turntable is still very respected for its
	price ($450 + arm).  Turntables made by Denon, Linn, Rega, Sota, and
	VPI are also recommended, but can cost even more.

11.5 What phono cartridge should I buy for my older turntable?
	The $30 Grado ZTE+1 is a great value for any home user but a purist.

	For the purist, there are still many choices, both moving coil and
	moving magnet.  Each sounds slightly different, and has its individual
	strengths.  The Sumiko Blue Point has been recommended at $125 along
	with the $125 Denon DL-160 and the $300 Shure V15 type V-MR.

11.6 Will phono cartridges still be around ten years from now?
	Most likely, there will still be cartridges available, but not in the
	variety available ten years ago.  They will become "Special Order" in
	some stores and unheard of in others.

	"Pro" or "DJ" cartridges will stay available in good supply,
	"Audiophile" cartridges will stay available and very expensive,
	"Mid-line" cartridges will become very scarce, and a few "Budget"
	cartridges will remain available in copious supply.  At the same time,
	some makers will drop their cartridge lines completely.

11.7 Will LPs still be around ten years from now?
	There is a strong movement of collectors and purists who will keep
	their collections and buy good used discs.  Count on these people to
	keep the used disc market hot for 25 years longer.

	As for new vinyl, almost none is being pressed today, and the art of
	cutting a master is being lost.  Some rejoice in its demise and others
	are in mourning.

	There are rumors that LP sales have increased recently in Japan.  Also,
	Polydor is now rereleasing older recordings on vinyl, and will 
	continue to press them as long as it is profitable.

11.8 What about CD green pens?
	In a nutshell, save you money.

	A CD player "reads" information on the disc with a laser light beam.
	Some believe that if you put a green stripe on the very perimeter of
	the disc, then the light beam will not reflect around inside the disc
	and will instead more clearly pick up the data.

	Scientific studies of the data coming off of the disc have failed to
	show any difference between a virgin disc and a green painted disc.
	I have not heard of double blind listening comparisons that have
	proved that there are people who can hear the difference, although
	many have performed uncontrolled tests with positive results.

11.9 What about CD stabilizer rings?
	In a nutshell, save you money.

	The data coming off of the disc is a serial string of ones and zeros.
	If this bit stream has jitter, then it may reach the D/A converter out
	of sync.  If this happens, then the actual analog signal recreated
	will have jitter, and won't be perfectly true.  The vendors of
	stabilizer rings say that using these rings will reduce jitter and
	make a more perfect signal.  Vendors also claim that the rings can
	increase the mass of a disc, making it spin more smoothly, and reducing
	transient load on the power supply from the motor.

	Some players will not play discs that have stabilizer rings on them.
	The clamp can't handle the thickness.  Other players play ringed discs, 
	but do not play them well, because the disc motor was not built for 
	the added load.

	With those exceptions, scientific studies of the data coming off of 
	the disc have failed to show any improvement going from a virgin disc 
	to a ringed disc.  I have not heard of double blind listening 
	comparisons that have proved that people hear the difference, either.

11.10 What about CD sprays (ArmorAll et al)?
	In a nutshell, save you money.

	Current wisdom is to avoid any disc coating or spray.  Some will 
	definitely damage the disc.

	There are many theories on what ArmorAll can do to a disc.  One
	is that it reduces static which will attract the delicate head of the
	laser detector to the disc.  Another theory is that the cleaner will
	fill voids in the disc with silicone, thereby making it easier to 
	read by reducing diffraction effects.

	Scientific studies of the data coming off of the disc have failed to
	show any difference between a virgin disc and a treated disc.  I have
	not heard of double blind listening comparisons that have proved that
	there are people who can hear the difference.

	One of the strongest proponents of ArmorAll issued a "recall" on his
	advice.  He now warns that ArmorAll can damage the disc.  He also
	advises that you can clean ArmorAll off treated discs with Dawn dish
	detergent.

11.11 Are 1-bit CD players better than multi-bit players?
	In a nutshell, they are virtually the same.

	There are some excellent sounding 1-bit players and some excellent
	sounding multi-bit players.  Some feel that the 1-bit technology has
	more future because it can be improved with the rapidly improving
	digital technology, while the multi-bit players improve with slowly
	improving analog technology.  Multi-bit also has its advocates.

	All of the various D/A converters try to do the same thing, and
	try to achieve the exact same ideal performance.  How well they 
	succeed is more a function of their skill and the quality of the
	parts that they buy than the technique that they use.

11.12 Are three lasers better than one in CD players?
	Some players have one beam, some three.  All use one laser diode to
	generate the beam.  Three-beam is just a different method for doing 
	track alignment.  Neither is better than the other.  

	There are good 1-beam players and good 3-beam players.  Manufacturers 
	want advertising claims, and "More Beams Is Better" sounded good to 
	some marketing people.  Trust your ears, not hype.

11.13 Is the BMG 8-for-1 deal good?
	Yes.  You have to put up with their frequent mailings. You can elect
	the "POSITIVE OPTION" and not have to answer each mailing to avoid an
	order.  You should expect to pay approximately $2.00 per disc for
	shipping and handling in the US and more elsewhere, but even at that
	price and assuming that you will buy one of their discs for $16.00,
	you still do well.  Assuming, of course, that you want at least eight of
	the discs that they are offering for sale.  Some states requires sales
	tax on BMG sales, and some states tax "free" discs, but the tax still
	is small compared to the discount from retail.

	BMG does not have a great selection and tends to sell very common
	titles.  Some rumored that BMG discs are inferior to the discs sold
	in normal retail chains.  This has not been substantiated.  In fact,
	BMG distributes their discs through retail chains, as well as through
	the mail, so you may get a BMG disc either way.

11.14 What should I do if there is a problem dealing with BMG?
	The number to reach BMG is 1-800-926-2338.  Their people have been
	very cooperative with me and others.  It is always good policy to
	confirm any phone call with a letter, restating the problem and the
	resolution you were promised over the phone.  It is also good practice
	to write down the name of the person you speak with.

	If BMG sends you something that you didn't order, DON'T OPEN THE
	PACKAGE.  Write REFUSED on the package and place it back in the mailbox.
	They will accept the return and credit your account for any charges.

11.15 How do I get out of the BMG racket?
	If you have taken any discs from BMG, you must either return what you
	have ordered or fulfill the terms of your original agreement.  This
	often means buying one disc at full price and paying for the shipping
	on all discs you ordered and received.

	Once you have done this, you can quit the club at any time.  Take your
	next order form and mark it with a bold marker in large letters "CANCEL
	MEMBERSHIP" and mail it to: BMG COMPACT DISC CLUB, PO BOX 91413,
	INDIANAPOLIS, IN  46291 USA.  It may take a month to fully take effect,
	but they will honor your request.  While waiting for the cancel order
	to take effect, be sure to return all future order forms marked the
	same way.  Otherwise, you may wind up with unwanted discs.

11.16 How do I get the most out of BMG?
	Only buy one disc at full price, fulfilling your obligation.  Request
	the "POSITIVE OPTION" so that you save on postage.  Only buy from
	special fliers.  Every month, except November and December, they send
	out a "Two for half price then one free" flier.  They have almost all
	of the stuff in the regular fliers.  They even offer "Buy one get two
	free" sometimes.  Wait for those special deals.  You can even order
	a disc from an October catalog using the order form that came with
	the February catalog.

11.17 What is a 1-bit (Mash, Bitstream) D/A converter (CD player).

11.18 What is the best under-$200 CD player?
	Once, Magnavox (and the identical Philips) CD players were known for
	poor reliability.  They are much better today.  Some believe that for
	sound, an under-$200 Magnavox is as good as any in its price range.
	Still, be sure to listen for yourself before you buy.

11.19 What is the best under-$500 CD player?
	Some recommend the Rotel 855 and 955.

11.20 What's wrong with the CD longbox?
	Some CDs are sold shrink wrapped in a square plastic storage box known
	as the jewel box.  This is the ideal packaging for CDs.  The shrink
	lets you know that the disc is new and unopened.  Other than that, the
	packaging is minimal.

	Unfortunately, most CDs are sold in a cardboard box that is more than
	2X the size of the jewel box.  This "long box" is ecologically wasteful
	and useless.  It rarely contains additional information about the disc
	or the artists.  Its primary purpose is to discourage theft in retail
	stores, but it is even poor at that.  These boxes are BAD.

	A few stores use a reusable long box.  When you buy a disc in one of
	these boxes, you take the disc and jewel box with you and leave the
	long box with the cashier for reuse.  Not perfect, but a good compromise.

11.21 How can I promote better CD packaging?
	Vote with your money.  Don't buy CDs packaged in the long box.  If you
	go to a store and they have CDs in the long box, tell the owner that
	you never buy CDs in the long box.  Then find stores which don't use
	the disposable long box.

11.22 How can I clean a dirty CD?
	Use a drop of dish detergent and lots of clean water.  Do not rub.
	Never rub or wipe in a circle.  Rinse the disc in running clear water,
	shake off most remaining drops, and lightly pat dry with a soft, clean
	cloth.

11.23 Can you repair a damaged CD?
	If the disc is lightly scratched on the bottom, then you can polish 
	out the scratch and probably repair the disc perfectly. If there are 
	lots of scratches or deep scratches, or there is damage on the top,
	you may be facing a lost cause.  The music information is immediately 
	under the label.  If you scratched the reflective layer, can you never 
	recover the disk.

	Before trying any repair, try washing the disc with clear water and a 
	bit of liquid dish detergent.  Do not scrub or rub hard.  Rinse the 
	disc with clear water and shake off as much water as you can.  
	Finally, wipe the last few drops off with a soft, clean cloth, in a 
	radial direction.

	SMALL scratches can be removed with a scrufty T-shirt and toothpaste,
	such as Tom's Toothpaste.

	You may wish to try a thin coating of Johnson's Klear floor wax on the 
	data side of the CD.  Often it will cover the scratches enough to allow 
	playing.  The refractive index is pretty close to polycarbonate, so the
	filled scratch will be virtually invisible.

	Noteworthy Music (800-648-7972) sells CD repair kits (#CDR 200, $11.99, 
	one shipping unit).  They seem to work as advertised, although getting 
	the disc to the point where you can't see any sign of the scratch does 
	take real care and persistance.

	You can buy professional plastic polishing compounds at many hobby 
	shops.  The ones used for polishing acrylics, plexiglas, etc. work.
	Ordinary lapidary jeweler's polishes also work.  You'll need a rough 
	polish to remove the scratches, then tin oxide to polish to a mirror 
	finish.  Telescope lens kits also work.  Finally, T-Cut, a car 
	paintwork polish, works well for big scratches. 

11.24 Can I add digital output to a non-digital-out CD player?
	Some Magnavox CD players using the Philips chip set can be modified.
	Look for a SAA7220 IC.  If it has one, then it can be modified.  If you
	have experience modifying electronic equipment, follow this procedure:

	Take pin 14 of the SAA7220 IC and remove whatever terminating resistor
	is on it.  Connect it through a 560 ohm resistor to the input of a
	wide band pulse transformer.  Tie the other end of the primary of the
	transformer to ground.  Pulse Engineering PE65612, Schott Corp 6712540,
	and Scientific Conversions SC916-01 all will work.  Bypass the primary
	through a 620 ohm resistor.  Connect the output of the transformer to an
	RCA jack.  Do not ground either side of the RCA jack. This output is now
	S/PDIF compatible. (Thanks for the tip to Positive Feedback)

11.25 What can I get in the way of a CD test disc?
	Many use the Hi-Fi News & Record Review test discs.  So far, these have
	received only positive comments.

	Chesky produces another test disc which contains some excellent imaging
	test signals (called LEDR), some well-recorded acoustic jazz, and other
	test signals.

	Stereophile produced a test disc which seems of limited value. 

12.0 High Fidelity Systems
	People frequently use the term "Stereo" to refer to a sound reproduction
	system.  To be more accurate, we will use the term High Fidelity System
	to refer to a pile of equipment including at least one source, at least
	one amplifier, and at least one speaker.  Common sources are turntables,
	CD players, tape players, tuners, and receivers.

12.1 What is a receiver?
	A receiver is a tuner, power amplifier, and preamp combined.  A common
	receiver has inputs for a turntable, a CD player, a tape deck, and
	perhaps one or two other sources.  It has selector switch(s), tone
	controls, and a volume control.  A receiver may have outputs for two
	speakers, or for more.

12.2 What is a tuner?
	A tuner is a radio receiver which can not directly connect to speakers.
	Sometimes, the radio in a tuner is higher quality than the radio in a
	receiver.  A tuner may or may not receive the AM broadcast band, but
	99.999% will receive the FM broadcast band.  Some also receive short
	wave bands, frequencies used principally by non-US stations.

12.3 How should I go about selecting a system?
	If you're looking to buy something, the first step is to figure out
	what you can spend.  If you're looking for a whole system, this gets
	tricky, because you have to allocate amounts for the different
	components.  The most popular current rule-of-thumb for a single source
	system (speakers, amp, 1 something-player) is to divide the money about
	equally among the three parts.  If you want several players, you'll
	have to decide whether they are all equally important, and so deserve
	the same amount of money; or whether some are less important, in which
	case you can spend less on them and put the savings elsewhere.

	This rule isn't hard-and-fast.  It's just meant as a starting point so
	you don't have to listen to every possible combination of equipment.
	If you are building around a CD player, you might spend a bit less on
	the player and a bit more on the speakers.  If you are buying turntable
	(or something else which plays by physical contact) on the other hand,
	it might be good idea to put a bit extra into the player.  The reason
	for this is that if you skimp on the turntable, then when you come to
	buy a better one you may find that your records have been worn out by
	the cheap player.  If you skimp on the speakers, on the other hand,
	then when you can afford better speakers the music will still be there
	on your records.

	See also 9.1, 9.2, and 11.1 for information on what to listen
	to and what to listen for when evaluating speakers, turntables, CD
	players, tape recorders, and systems in general.

12.4 How can I improve the sound of my stereo?
	The cheapest improvement you can make, and perhaps the most effective,
	is to position your speakers carefully and correctly.  See 9.4, above.
	This will improve the frequency response flatness, making it easier to
	hear every instrument and voice.  Setting speaker position correctly
	can also improve the three-dimensional recreation of a stereo image.

12.5 Do I want a combo system or separate components?
	Combo systems used to be cheap jokes; that's not always true now.  Some
	sound very nice; there are even some made by "audiophile" companies, 
	and they sound even nicer.  They've got lots of advantages.  They take 
	up less space.  The controls tend to be well-integrated, especially if 
	they are remote-controlled.  Therefore, they are easy to operate; this 
	can be a major plus if some of the people who'll use it are afraid of, 
	or not very good at, technology.  Also easy to set up, and don't leave
	millions of wires dangling all over everywhere.

	If you do go for a combo, get a brand name -- either an audiophile 
	company, or a good "consumer electronics" company.  Brand-X combos are 
	generally overpriced, and unpleasant.  If possible, buy it somewhere 
	you can listen to it first, such as a "real" hi-fi shop.  Mid-range hi-fi
	shops sell combos, as a way of introducing beginners to quality sound.

	In most good combos, the speakers are the weak link.  If you do
	go for a combo, you can almost always improve the sound drastically by
	buying a set of better speakers.  Better speakers start in the 
	$100-$200 price range.  (Some of the best combos come without speakers, 
	forcing you to do this.) A good combo (probably with replacement 
	speakers) can give you a very pleasant musical experience.

	Sounds good, you say, so why do people bother with components?  Well,
	you can get better sound with a component system -- but usually at the
	expense of convenience and size.  A good component system will normally
	require a mixture of boxes from different makers to get the best
	results, so you've got to spend more time listening to things.
	However, if you listen to your music seriously, then the performance 
	of a component system is the reward for that extra work.

	Components are harder to set up and operate.  However, as noted, you
	can get better sound.  You also get more flexibility.  If, for example,
	you decide you want a better CD player, you just replace the CD
	player.  With a combo system, you've got to replace the whole system.
	If your component tape deck breaks, you can remove it from the system 
	and take it in for repair or replacement. With a combo, the whole 
	system has to go in for repair or be replaced.  

	When you want to add some new recording medium to your system 
	(laserdisc, VCR, DAT, DCC, MD, ...), if you've got components you 
	just go buy the appropriate box.  Many combo systems do not have 
	places (or many places) to attach extra bits, so again you could be 
	looking at replacing the whole thing.  With a component system, you 
	can add a turntable; most modern combos can't cope with turntables 
	any more.  Do you have a record collection?

	If you're really not sure, components are the safer bet; if
	you're going to make a mistake, that's probably the better way to be
	wrong.  But, if you're sure that a combo would be best for your
	needs, it can be a totally reasonable choice.

	Now, some people may be tempted by one-maker 'component sets',
	particularly the modern, miniature ones.  They tend to be equivalent 
	to combos.  Most of them use non-standard connections, rather than 
	the normal twin phono plug, so that it's likely you can't swap or add 
	components anyway.  Even where they use standard interconnects, they 
	may rely on non-standard interconnections for control purposes.  In 
	a few cases, they also rely on sharing power, with a power supply 
	in only one of the boxes and the rest taking low-voltage connections 
	from that.  And, no one maker makes the best everything.  By default, 
	assume that they will have the same disadvantages (and most of the 
	same advantages) as combos.  If it's important for it to work with 
	"standard" components from other makers, be sure to ask before you buy.

	And, if you're in doubt, go for separate components.

12.6 How can I get better FM radio reception?
	A. Use a (better) antenna. (See 12.7 and 12.8 below)
	B. Use a (more) directional antenna. (See 12.7 and 12.8 below)
	C. Aim your directional antenna.  Rhombics are ungainly to move,
		but Yagis and dipoles are small enough to point right at the
		station.  With the dipole, to tune in a station to the East,
		run the antenna North-South.  With a Yagi, point the individual
		elements North-South with the smallest element on the East end.

12.7 How good are these compact FM antennas?
	For receiving, small is ugly.  The bigger the antenna (all else equal)
	the better.  Of course, all else is never equal, but these fancy,
	expensive mini antennas tend to be awful.  Some compensate for their
	small receiving structure with a small antenna signal amplifier.
	However, the quality of that amplifier is often no better than the
	quality of the amplifier in your tuner or receiver, so the antenna
	just gives you a stronger signal, complete with noise.

	All of that said, some compact FM antennas can work better than a simple
	dipole in some situations.  They tend to have an internal amplifier,
	which helps with weak signals.  Some are directional.  Some aren't.
	If possible, be sure that whatever you buy can be returned for a refund
	if it doesn't work out well for you.

12.8 What makes the best FM radio antenna?
	Although there is no "best" antenna for everyone, one of the most
	directional is the "rhombic".  Being very directional, this antenna can
	select one weak station out of many strong ones, or one group of
	stations originating from a general direction.  This antenna is very
	long, and made up of four pieces of wire with feedline at one end for
	antenna connections and a resistor at the other for termination.
	Rhombics for FM broadcast band use are at least 15 feet (4.5 meters)
	long, but can be made fairly narrow, less than 3 feet (1 meter) wide.
	A more narrow antenna will be more directional. A longer antenna will
	give a stronger signal.

	Another very directional antenna is the "yagi", which looks just like
	a common TV antenna.  You can even use a common TV antenna as a very
	good FM antenna.  The FM and TV bands are very close together.  It has
	the advantages of being cheap, directional, and easy to rotate.

	One of the simplest and easiest to make antennas is the folded dipole,
	made from 300 ohm twin lead.  It is approx. 58" long.  This antenna is
	surprisingly good for receiving signals in a moderately strong signal
	area.  Folded dipoles come with many tuners and receivers as a standard
	accessory.  They are also available for approximately $2.00 at audio
	and department stores.
	
	Whatever antenna you have, you can often get it to work better for
	specific stations by moving it to the best position.  In the case of
	the folded dipole, sometimes it works better vertically, and other times
	it works best horizontally.  Sometimes, you can get that one elusive
	station to come in perfectly if you bend the two ends of it at funny
	angles.  Don't be afraid to experiment.  One warning.  As atmospheric
	conditions change, the best antenna placement may also change.

	An excellent reference book on antennas is printed by the American
	Radio Relay League (ARRL).  It is called the Antenna Handbook.  It has
	fairly complete antenna theory, practical information such as charts,
	drawings, comparisons, and tips on construction and adjustment.  The
	ARRL is founded and chartered as a non-profit organization to better
	amateur radio, and antennas are a vital part of amateur radio.
		American Radio Relay League
		225 Main Street
		Newington CT 06111 USA

	Also useful:
		Practical Antenna Handbook by Joseph J. Carr
		Tab Books #3270/McGraw Hill - ISBN 0-8306-3270-3

12.9 What about power line conditioners?
	Each home and each outlet has slightly different power line impedance 
	and power line noise.  Each amplifier is effected by power line 
	impedance and power line noise differently.  Power line conditioners
	try to reduce this line noise.  Some also change the power line
	impedance in a way which is supposed to be better.  We will leave it to 
	your ears to decide if these devices help the sound of your system
	enough to justify their expense.

12.10 How can I reduce vibration sensitivity?

12.11 What equipment can I buy that is 100% made in the USA?  Europe?
	There are many lines of equipment that are carefully handcrafted in the
	USA.  Unfortunately, these systems are usually the high-end ones.  If 
	you are looking for a bargain, you won't find it in any US manufacturer.
	Notable American manufacturers that make excellent (though expensive)
	equipment include Levinson, Krell, Jeff Rowland, and Audio Research.

13.0 Listening Rooms and Houses

13.1 How should I place speakers in my room?  What size room is best?
	Although nothing is ever ideal, there are a few room dimension ratios
	that are good for listening rooms:
		Height		Width		Length
		1		1.14		1.39
		1		1.28		1.54
		1		1.6		2.33
	If your room isn't shaped like that, don't worry.  The differences are
	minor.  However, if your room is asymmetrical, then you may have very
	poor imaging.  You might consider a different room or some room
	treatment if you have these problems.

	An excellent starting point for speaker placement is to get stands which
	put the tweeters at ear level.  Then measure the listening room diagonal
	dimensions.  Divide that measurement by three.  Place each speaker that
	distance from a corner, on the room diagonals.

			----------------------------------------
			|                                      |
			|                    L                 |
			|                                      |
			|           S                 S        |
			|                                      |
			----------------------------------------

	Place your listening position midway between the two speakers and
	approximately half way from the speakers to the wall.  Be sure that
	there is nothing in the "triangle" formed by the listening position
	and the speakers.

	Try this and then move things 12" at a time and see if you can improve
	the sound.

13.2 How do I wire a house for sound?
	A fundamental principal of physics is that the farther a signal
	travels, the more the signal will be degraded.  Translate this to
	mean that the shorter the wire, the better.  Understanding this,
	the idea of running speaker cable between  every room of the house
	isn't as attractive as it first seems.	

	If you still decide to wire your house for sound, you should do it
	at the same time you're wiring for telephone and electricity.  It is 
	possible to wire a house after the walls are closed, but it becomes 
	very difficult.

	It is economical to use common house wire (Romex, UF, NM, etc) for 
	speaker wire in the walls, but this may violate building codes.  Check
	with an electrician or inspector first.  It will also confuse future 
	electricians, so label the wire clearly, all along its length.  

	If you want to make your house like a recording studio, it is best 
	to use the techniques of recording studios.  When studios run long 
	lengths of sound cable from one room to another, they drive the cable 
	with 600 ohm line amplifiers.  They also use shielded, twisted-pair 
	cable.  They only connect the shield at one end of the cable.  
	Finally, they use balanced inputs at the other end of the cable.

13.3 Where can I read more about listening room construction and tuning?
	"Building a Recording Studio" by Jeff Cooper
		Mix Bookshelf
	"Handbook for Sound Engineers"
	"The Master Handbook of Acoustics" by F Alton Everest
	"Sound Engineering 2nd Edition" by Don and Carolyn Davis;
		Howard W. Sams & Co. (C) 1990
	"Good Sound" by Laura Dearborn
		Introductory, but clear and accurate
	"Sound Recording Handbook" by John M. Woram
		Howard W. Sams & Co. #22583
		Excellent General Reference
	"Audio Technology Fundamentals" by Alan A. Cohen
		Howard W. Sams & Co. #22678
		Overview of Audio Theory
	"Introduction to Professional Recording Techniques"
		by Bruce Bartlett
		Howard W. Sams & Co. #22574
	"Modern Recording Techniques" by Hubar and Runstein
		Howard W. Sams & Co. #22682
	"Sound Studio Production Techniques"
		by Dennis N. Nardantonio
		Tab Books

14.0 Recording
	There are more different recording systems available today than ever
	before.  Digital and analog are both available to the consumer.  With
	the advent of consumer digital recorders, used pro analog recorders are
	becoming available for surprisingly low prices.  Now may be the time
	for you to buy a microphone and recorder and make your first!

14.1 What is DAT?  What is its status today?
	DAT (Digital Audio Tape) is currently the standard professional
	digital format for 2-track digital recording.  DAT had a short-lived
	consumer presence, but never "made it".  As digital recorders have no
	tolerance for clipping, using a DAT recorder takes a slightly different
	knack.  The results can be worth it, however, as DAT format offers the
	same resolution and dynamic range as CDs.  DATs record for up to 2 
	hours on a tape, and can  run at three different sampling rates:  
	32 kHz, 44.1 kHz (for CD), and 48 kHz (the DAT standard).

14.2 What is DCC?  What is its status today?
	DCC is Philips' attempt to modernize the regular cassette.  DCC decks
	can play analog cassettes, and can record new Digital Compact
	Cassettes.  They use stationary heads (DATs use rotary heads as do
	VCR's), and although they are digital, they use lossy compression to
	fit all the data on the cassette.  Although DCC sound quality is far 
	better than the 1960 standard cassette, the DCC does not have the sound 
	quality present in DAT or CD.  DCC may be a good choice for consumers 
	who want to assemble mix tapes for cars or walkmans, but is not suitable 
	for any professional applications.  As of December 1992, DCC is very
	new, DCC equipment is very expensive, and the ultimate future of DCC
	is not assured.

14.3 What about writable compact discs?  What is the status today?
	Recordable CD's are available, but are very expensive.  Blank discs 
	sell for approximately $35 each, and the recorders start at around
	$6,000.  These units are mostly used by recording studios and other
	audio professionals.

14.4 What is the best cassette deck under $200?

14.5 What is the best cassette deck under $400?

14.6 What is PASC?  Can I hear the effects?

14.7 What is SCMS?  Can I hear the effects?
	SCMS (Serial Copy Management System) is a copy-protection system 
	intended to stop rampant piracy of commercial recordings to digital 
	tape.  SCMS allows the home taper to copy from a CD to a digital tape, 
	but prevents anyone from digitally copying that new digital tape.

	You CANNOT hear SCMS.

14.8 How can I bypass SCMS?
	There are professional devices used by engineers to manipulate the 
	digital bitstream, but they cost several hundred dollars and are not
	cost effective for consumers.  If you need to make perfect digital
	copies of digital copies, buy a professional digital recorder.  Pro 
	models do not have SCMS, are more durable than consumer recorders,
	and may have better quality electronics than consumer models.

14.9 What's this about a tax on DAT?
	Every digital audio tape recorder and every blank digital tape sold
	in the USA is priced to include a "premium" or "tax".  This tax is
	collected by the US Copyright Office and distributed to the recording
	artists and record companies that own the copyrights to commercial
	music.  These fees are suposed to repay them for lost royalties.

	Many believe that this "tax" is illegal, because it represents an
	assumption that the buyer will use the recorder and tape to violate
	a copyright, and not to record their own works.  A founding principal
	of the USA legal system is that everyone is assumed innocent until
	proven guilty.

	If you believe that this law is unjust, write your elected 
	representatives.

14.10 Is it legal to copy an LP, CD, or pre-recorded tape?
	It is legal to copy LP's, CD's, etc. for your own private use (such as
	to copy a CD to play on your walkman).  It is not legal to copy these
	sources for commercial purposes, or to give the copies to others.

	It is as of yet unclear whether you own the rights to sell or give away
	a copy of a recording if you made the copy on media which was sold with
	an included digital audio tax.

14.11 How do I clean and demagnetize tape heads?
	To clean tape heads, use pure isopropyl alcohol and lint-free swabs.
	wipe the metal parts of the transport with alcohol (DON'T wipe the 
	rollers!) and allow them to dry.  Throw the swab away after use.
	Be exceedingly careful when cleaning the heads on a DAT.  DAT heads
	are notoriously easy to misalign by incorrect cleaning.

	Practical tape head demagnetizers are available for under $10.  Try
	to find one with a plastic coated tip.  If you can't find one which
	is plastic coated. you can slip a drinking straw or plastic tube
	over the tip for the same effect.  This plastic will prevent the
	demagnetizer from scratching the head.

	Before plugging in the demagnetizer, remove all tapes from your
	working area and unplug the recorder.  Hold the demagnetizer away
	from the recorder as you plug it in.  Slowly bring the tip of the
	demagnetizer up to the tape head and slide it back and forth across
	each tape head for five one-second strokes.  Then pull it away from
	the head slowly and go on to the next.  After demagnetizing the heads,
	use the tip on each metal tape guide with a similar five strokes.
	Last, slowly pull the demagnetizer far away from the recorder and
	unplug it.  Recording engineers use a demagnetizer before each
	recording session.

14.12 How do I adjust a tape recorder for best results?
	Adjusting a tape machine for best results usually requires special
	equipment and test tapes.  Unless you know what you're doing, leave it
	for a pro.  If you are serious about doing it, buy the service manual
	for your particular tape recorder.  It will list a detailed procedure,
	as well as describe the correct test tape and tools.

	As for setting of record levels, it is best to experiment with 
	different levels on different tape brands.  Different formulation 
	will reach saturation for different levels.  Generally speaking, the
	transients on a Chrome tape should peak at about +6 dB above 0, though
	some formulations can take significantly hotter signals.

14.13 Where can I get new pinch rollers or drive belts?
		Projector-Recorder Belt Company
		Whitewater WI USA
		800-558-9572

14.14 What is a good rubber (pinch) roller cleaner?
	Teac RC-1 available from 
		J&R Music World
		59-50 Queens-Midtown Expressway
		Maspeth NY 11378-9896 USA 
		800-221-8180 or 718-417-3737
	Tascam Rubber Cleaner RC-2 available from:
		Tape Warehouse
		Chamblee GA
		1-404-458-1679

14.15 How can I program a recorder to tape a radio broadcast?
	Radio Shack and Panasonic make a clock/radio/cassette that can be set
	to record at a specific time.  Radio Shack also sells 120 minute
	cassettes, which can be used for 60 minutes per side.  The recorders are
	not high quality, and the long tapes are fragile, but it works.

	You can buy "appliance timers" at hardware stores that will start and
	stop an appliance at a specific time.  Radio Shack sells fancier
	versions of the same thing for more money. Gadget freaks love "X-10"
	control systems. These can be configured to do the same thing. All
	require a recorder that can be left in RECORD mode.  Such recorders are
	identified by a "TIMER" switch on the front panel.  Many cassette decks
	have a TIMER switch for use with timers.

	Memorex sells a "CP-8 Universal Remote" with a built-in timer.  $93 from
	Crutchfield or $90 from J&R Music, 59-50 Queens-Midtown Expressway,
	Maspeth NY 11378-9896 USA, 800-221-8180 or 718-417-3737.  This can be 
	set to start a recorder at a particular time.  As the recorder will be
	started from a remote control rather than by the power line voltage, no
	timer switch is required. Others similar universal remotes with timers
	may exist.

	Use a VCR for audio-only recording.  Hook the audio in to the output of
	a radio, tuner, or receiver.  You may also have to connect some video
	signal to the VCR so that the sync circuits work correctly.


-- 
Bob Neidorff; Unitrode I. C. Corp.  |  Internet: neidorff@uicc.com
7 Continental Blvd.                 |  Voice   : (US) 603-424-2410
Merrimack, NH  03054-0399 USA       |  FAX     : (US) 603-424-3460