HDTenEightyP/NetNews huggingface dataset:
From: kautz@research.att.com
Subject: magnavox 6815 port cd?
Date: Tue, 29 Dec 1992 16:29:18 GMT
Distribution: rec
Reply-To: kautz@research.att.com
Organization: AT&T Bell Laboratories

Does anyone have experience with the new Magnavox 6815 portable car cd
player?  Local ads make it sound like it has electronic anti-shock,
but the price seems way too low ($229 vs > $400 for similiar Sony) for
that to be the case.
--
---- Henry Kautz

:internet: 	kautz@research.att.com
:uucp:		allegra!kautz
From: rmp@crashnburn.Eng.Sun.COM (Richard Pottorff)
Newsgroups: rec.audio
Subject: Re: quiet current sources.  Any ideas?
Date: 23 Dec 1992 18:05:49 GMT
Organization: Sun
Distribution: usa
NNTP-Posting-Host: crashnburn

In article <1992Dec21.150028.1331@porthos.cc.bellcore.com> gfl@herahera.cc.bellcore.com (lenahan,grant f) writes:
rg@kunikpok.UUCP (R.G. Keen) writes:
> gfl@herahera.cc.bellcore.com (lenahan,grant f) writes:
> 
> > I need to modify an input buffer for lower noise.
> > 
> > Can anyone suggest a method for making a _quiet_
> > 15-ish mA constant current source?  The olde zener-
> > bipolar solution is proving noisy.
> > 
> 
> Try bypassing the zener.

Oh, I've tried quite a few things.  Understand that a B-E
junction is very noisy, and that the effective impedance of a
current source is very high.  Thus voltage noise across it
is also high.

Combine this with the amplifying effect of a BJT on any
voltage reference noise, and the problem becomes significant -
and hard to fix. 

The answer will fall in one of two areas:
	1 - filter the BE junction (can't filter output or zener)
	2 - find an alternate current source

I prefer the latter, and still solicit inputs.  But about 20 hours
of various people's time have already gone into this - its become
annoying!

Thanks again, and thanks for your suggestion.  Regrettable its
not so simple as a noisy Zener.

Grant
gfl@hera.cc.bellcore.com

I suggest:

Why not use a large resistor (in relation to your impedance) in series with
a appropriately valued voltage source?

E=IR. R=E/I.  Let E=1, then R=1/15mA; R=66.67 Ohms. OK, that's not a big
enough resistor. Lets scale E and thus R by using a 20V supply.
R=1333.333... Ohms. 

What happens, is the size of R swamps any changes of resistance (if its 
quite a bit (at least an order of magnitude) smaller than R. You can keep
pushing R up if you keep pushing E up as well.

Rick
--
Stolen signature:
GILLETTE'S PRINCIPLE:
  "If you want to make people angry, lie. If you want to make
   them absolutely livid with rage, tell the truth."
From: shetline@bbn.com (Kerry Shetline)
Newsgroups: rec.audio
Subject: Re: Selecting an LD Player
Followup-To: rec.audio,rec.video
Date: 1 Jan 1993 23:09:13 GMT
Organization: BBN
Distribution: world
NNTP-Posting-Host: bbn.com

In article <1993Jan1.194240.17177@midway.uchicago.edu>,
cal@gsbux1.uchicago.edu (Cal Lott) wrote:
> 	Is that what *Theta* claims about the player, or *Video* claims?
> Theta is highly regarded company, and mechanical jitter just isn't
> something that I think they would be terribly interested in.
> 
> 	On the other hand, I could see some writer or editor at Video
> magazine coming up with a gross misunderstanding of jitter and then
> printing it.

I'd have to try to dig up the old issue, if I've still got it. I'm fairly
certain that I remember wording to the effect "the manufacturer claims...".
What botherered me was that there is much more solid ground for claiming
video improvement, but that was not emphasized as strongly.

P.S.: As an approximation of the visual experience, modern video is about
as effective as an Edison Cylinder in recreating an audio experience. Maybe
top-notch HDTV will reach the relative level of 78 RPM shellac discs.

-Kerry
From: shetline@bbn.com (Kerry Shetline)
Newsgroups: rec.audio
Subject: Was: Re: Please excuse-just a test
Followup-To: rec.audio
Date: 28 Dec 1992 02:11:18 GMT
Organization: BBN
Distribution: world
NNTP-Posting-Host: bbn.com

In article <24491@alice.att.com>, ark@alice.att.com (Andrew Koenig) wrote:
> 
> > I getting some strange problems with the way my news software is handling
> > word-wrap.
> 
> Perhaps you should upgrade the cable you use to connect your keyboard
> to the rest of your system.

Gee, I dunno whether that would fix the word wrap, but it might sharpen the
text pixels, improve the imaging of my writing, and give it that tight
consonant response that retains a good airy quality about the vowels that
you can only get from a keyboard cable that costs a few months salary ;-)

-Kerry
Newsgroups: rec.audio
From: gmw1@cunixa.cc.columbia.edu (Gabe M Wiener)
Subject: Re: Recorded using B&W speakers
Reply-To: gmw1@cunixa.cc.columbia.edu (Gabe M Wiener)
Organization: Columbia University
Date: Wed, 23 Dec 1992 20:51:54 GMT

In article <BzptF8.DD5@dcs.glasgow.ac.uk> jack@dcs.glasgow.ac.uk (Jack Campin) writes:
>> The advantage of using B&W speakers (or another fine brand) for monitoring
>> is that you bring out all the flaws in your recording right then and there.
>> Recordings monitored and judged through transducers of less-than-ideal 
>> quality often have flaws that are audible through high-end audiophile grade
>> systems.  Many feel that these problems can be avoided by monitoring on
>> such a system in the first place.
>
>Somewhere I read that recording companies in the 60s took the exactly
>opposite approach when mixing-down pop tracks: the last stage in the chain
>was the sort of speaker you'd find in a cheap trannie on the beach.  Since
>that was where their product was aimed, that was what they balanced it for.

Well, that's how popular music is mixed today.  You mix for your
audience.  If you go into J. Randon Recording Studio, you'll usually
find three pairs of speakers:

	1.  A large pair of speakers mounted on the front wall facing the
	    engineer's position ("The overheads")
	2.  A somewhat smaller set of speakers, usually (Yuck) Yamaha NS-10M's
	    or Tannoy PB8's (better), placed right on top of the console
	    overbridge ("The near-fields")
	3.  In some studios, you'll find a cheap pair of speakers, such as
	    the Radio Shack Minimus 7's, the Auratones ("Awfultones"), 
	    any cheap boombox, etc. ("The little speakers")

Not all studios have #3, but most studios that mix for pop music do.
If you are mixing, say, rap music, you will mix it to sound best
through a walkman or a boombox.  You always mix for your intended
audience.

However, popular music recording is a very different game from
classical.  In pop music, you try to *create* a certain sound.  In
classical, you try to *re-create* a certain sound.  To that end, you
always want to use the highest quality monitor system when recording
classical.  It would be pointless not to.  Classical recordings are
mixed with the highest standards in mind, whereas most pop music is
mixed to sound good for the majority of its listeners.


--
Gabe Wiener - Columbia Univ.     "This 'telephone' has too many shortcomings 
gmw1@cunixa.cc.columbia.edu       to be seriously considered as a means of 
N2GPZ in ham radio circles        communication. The device is inherently of
72355,1226 on CI$                 no value to us." -Western Union memo, 1877
From: chrisc@gold.gvg.tek.com (Chris Christensen)
Newsgroups: rec.audio
Subject: Re: Question about rear speakers for surround sound
Date: 23 Dec 92 01:09:01 GMT
Organization: Grass Valley Group, Grass Valley, CA

In article <541@bit.UUCP> grego@bit.UUCP (Grego Sanguinetti) writes:

>Chris, have you looked at the surround line outs on a spectrum analyzer?
>I have not. I'ld be interested to know what actually is there. I tried
>using my BA-150's for surround. They have good bass. It seemed that enough
>bass was comming their way to make them work.

No I haven't.  The surround decoder I use has a filter in the surround
channel.  

Be aware that the surround channel LF spec is -6 dB @100 Hz.  That
spec will still allow a lot of audible bass but not the deep bass of
the front speakers.

Chris sez:

>>I have said it before and I will say it now,  the selection criteria
>>for the surround speakers is: smooth amplitude and phase response will make
>>the surround "sound" at it's best! 

Grego responds:

>Also agree with this, but add dispersion to the list. Still my favorite for
>surrounds are plannars. I do however dissagree with Chris on the placement
>as I prefer them on the side and he prefers the rear wall. My rear wall is
>not an option due to ergonomic reasons (it's my kitchen!) so it's a good thing
>I like the sides eh?

Yes sir! it's a good thing to like the side in your situation!  And
dispersion is a good trait for surround speakers,  basically anything
that will reduce the localization of the surround speaker system as a
sound source.

And just in case anuone is thinking if that new "omnidirectional"
outdoor speaker that Radio Shack has.....I don't think it's a good
choice for a surround speaker.  It's fine for a patio speaker  if
you aren't an audiophile who can't except anything but the best!
-- 
Chris Christensen                  The opinions I express are my own,
chrisc@gold.gvg.tek.com            and sometimes they are wrong!
916-478-3419 FAX 916-478-3887      After all, I *AM* only human.
Newsgroups: rec.audio
From: Mike_Benna@mindlink.bc.ca (Mike Benna)
Subject: Re: Velodyne ULD-12 hums - why, and can it be fixed?
Organization: MIND LINK! - British Columbia, Canada
Date: Tue, 29 Dec 1992 18:56:22 GMT

> Cal Lott writes:
>
>         Is the sound coming from the woofer itself? If so, it is
> possible that the active servo circuit of the Velodyne thinks that it
> is receiving an input signal.

Yes, it is. From what you say it sounds like this is an abnormal "feature"
and I should get it repaired.
--
Mike_Benna@mindlink.bc.ca      Vancouver B.C., Canada
MindSpan Technologies          Video Game Design and Development
HardBall III, Summer/Winter Challenge, Joe Montana Football, Face Off!, etc
Newsgroups: rec.audio
From: bill@bilver.uucp (Bill Vermillion)
Subject: Re: Analog CDs (was: CD Sound Quality)
Organization: W. J. Vermillion - Winter Park, FL
Date: Sat, 26 Dec 1992 15:52:49 GMT

In article <PHR.92Dec25153015@napa.telebit.com> phr@telebit.com (Paul Rubin) writes:

>    You're too pessimistic.  Analog recording on a 12cm disc could hold as
>    much as 26 hours of CX encoded sound.  

>Something like this would probably send record company executives
>through the roof, especially if it were consumer recordable.  :-(

Well - it's been thought of.  When Sony was doing their first
digital disc research they figured that you could easily put a
days worth of music on a 12" disk.
 
 They could envinsion no scenarios where consumers would wan't
to buy something that long, so they scrapped that idea.  It
took Philips to reduce the size of the disc.  And then with the
joint Sony/Philips venture the current CD size was finally
standardized on - legend has it was that it was to a length of
a favorite piece of music for one of the Sony executives - or
something like that.     Sony just couldn't see the forest
because of the trees.



-- 
Bill Vermillion - bill@bilver.oau.org  bill@bilver.uucp
                - ..!{peora|tous|tarpit}!bilver!bill
From: allana@hpmwtd.sr.hp.com (Allan Armstrong)
Date: Thu, 24 Dec 1992 16:40:46 GMT
Subject: Re: Carver and the FAQ
Organization: HP Santa Rosa Site (SRSD MWTD)
Newsgroups: rec.audio

steve@endgame.gsfc.nasa.gov (Steve Rezsutek) writes:

>Well, I won't even pretend to give a definitive answer (ask the
>guys in sci.electronics?), but "magnetic field power
>amplifiers" are "real" things.  They use an element, called a
>"reactor" I believe, which I recall being something like a
>cross between a tube and a transformer (not really, but bear
>with me).  A little bit of current flux in one winding can
>*control* (not induce) a much larger current flux in another
>winding.  In their cruder forms they often find use as dimmers
>for stage lights.

If you look at the schematic of a Carver amp (I'm assuming that the one
"magnetic field power amplifier" I've looked at is representative of the
others he makes.) you'll see that the amplifier does not operate off of
the principle stated above. Thus, Carver's name is a misnomer -- in my
mind a sleazy lie made strictly for marketing benefit.

There's enough snake oil in this business without this kind of crap.

Allan
Newsgroups: rec.audio
From: rviswana@bagpipe.cis.ohio-state.edu (r viswanathan)
Subject: Information capacity of a CD
Organization: The Ohio State University Dept. of Computer and Info. Science
Distribution: usa
Date: Tue, 29 Dec 1992 03:56:21 GMT

 Can someone tell me how many minutes of music can be stored on a CD.(Theoretically). I have seen some CDs which store nearly 80 minutes. And some  store
just 35 mins or so. 

 Does reproduction suffer if more music is crammed into a CD (like an LP)?

 How do the new formats i.e MD and DCC compare with the CD as far as 
 information storage goes?

 Please post all replies to the newsgroup.

 Thanks.

 --Ram.
From: cal@gsbux1.uchicago.edu (Cal Lott)
Newsgroups: rec.audio
Subject: Re: Question about rear speakers for surround sound
Date: 28 Dec 92 03:34:13 GMT
Organization: University of Chicago Computing Organizations

chrisc@gold.gvg.tek.com (Chris Christensen) writes:

>In article <541@bit.UUCP> grego@bit.UUCP (Grego Sanguinetti) writes:
>
>>Chris, have you looked at the surround line outs on a spectrum analyzer?
>>I have not. I'ld be interested to know what actually is there. I tried
>>using my BA-150's for surround. They have good bass. It seemed that enough
>>bass was comming their way to make them work.
>
>No I haven't.  The surround decoder I use has a filter in the surround
>channel.  
>
>Be aware that the surround channel LF spec is -6 dB @100 Hz.  That
>spec will still allow a lot of audible bass but not the deep bass of
>the front speakers.

	True. And also keep in mind that the subwoofer output gets a
signifigant portion of the surround bass, as well. (For those people
lucky enough to enjoy a subwoofer in their setup.)

>Chris sez:
>
>>>I have said it before and I will say it now,  the selection criteria
>>>for the surround speakers is: smooth amplitude and phase response will make
>>>the surround "sound" at it's best! 
>
>Grego responds:
>
>>Also agree with this, but add dispersion to the list. Still my favorite for
>>surrounds are plannars. I do however dissagree with Chris on the placement
>>as I prefer them on the side and he prefers the rear wall. My rear wall is
>>not an option due to ergonomic reasons (it's my kitchen!) so it's a good thing
>>I like the sides eh?
>
>Yes sir! it's a good thing to like the side in your situation!  And
>dispersion is a good trait for surround speakers,  basically anything
>that will reduce the localization of the surround speaker system as a
>sound source.

	Dispersion is precisely the reason that manufacturers such as
Cambridge Soundworks make speakers with divers that fire parallel to the
intended audience location instead of directly at them. In fact, this may
be a requirement for a THX-certified surround speaker, but I'm not sure.

>And just in case anuone is thinking if that new "omnidirectional"
>outdoor speaker that Radio Shack has.....I don't think it's a good
>choice for a surround speaker.  It's fine for a patio speaker  if
>you aren't an audiophile who can't except anything but the best!

	Well, you don't have to be an "audiophile" to want better
speakers than the ones that Radio Shack makes. 8-O

	8-)  Seriously, though, I haven't heard them, so I probably
shouldn't judge a book by its cover or a speaker by its manufacturer.

	I have also heard that one would want speakers that are all
constructed by the same manufacturer, as such models would share
similar characteristics sonically. This idea is probably just 
manufacturer propaganda, but I submit it for your consideration.

					-Cal
--
----------------------------------------------------------------------
Cal Lott          "Oh, I see-- I thought 'no' meant 'spoon'!" --Dan
Email me, baby!   cal@gsbux1.uchicago.edu   cjl1@midway.uchicago.edu
----------------------------------------------------------------------
From: jj@alice.att.com (jj, curmudgeon and really disguted scientist)
Newsgroups: rec.audio
Subject: Re: CD SOund QUality
Date: 23 Dec 92 03:25:11 GMT
Article-I.D.: alice.24473
Reply-To: jj@alice.UUCP (jj, curmudgeon and really disguted scientist)
Organization: NJ State Home for Bewildered Terminals

In article <Jonas.Palm-221292205230@fastpath-37.orgk2.lth.se> Jonas.Palm@orgk3.lu.se (Jonas Palm) writes:

>Could you please make the above statement absolutely clear.
>Do you mean that the recording engineer should have (say)
>18 bits at his disposal, for instance in order to be able to 
>maintain a reasonable safety margin when recording, but that
>16 bits should then be sufficient in the actual CD-medium?
Well, as some fellow name of Johnston said a few years ago
(He didn't write a paper for his talk, so there's only the
tapes, I'm sorry to say) said in a talk on the future
of digital and compression at an AES meeting
in Toronto, if we had 24 bits we could
reference all of our stuff from below threshold of hearing to
above the threshold of pain, and if we made all our recordings
that way, we could use the recording as a DOCUMENT as well
as a recording, i.e. we could go back and reestablish conditions
given a little simple calibration.

How does this relate to 18 bits?  I'm looking at a piano recording
right now, the largest absolute value any sample on it is about 2400.
This is somewhere like 4 bits down TO START.  Perhaps if we had two
more bits, I wouldn't have to listen to the miserable quatization
noise and also have to handle such stuff in encoding/decoding
algorithms.

I've seen albums with clipping on them, I've seen albums that
just ignore the 4 MSB's, and I've got one or two that I'd
SWEAR were only 12 bits to start with.

It's this loss of resolution that I suspect is brought on by
non-normalized digital transfers in the recording chain that
annoy me.  Two bits would make it disproportionally better,
if you do some simple math.  As far as the recording engineer
is concerned, that's not what seems to be the problem.
The problems seem to come later, in what I can only
describe as bizzare levels present on the final CD, for
the most part.  The few that seem to have 12 bits (MSB used)
might be recording level problems that somebody tried to fix,
of course.

(18 bits)
>in the recording-playback chain would seem to imply this, but
>you may not agree.

Why would anyone care if I agree? After all, as the article
I orginally replied to in this thread suggests, I'm only
a crank audiophile, or so my e-mail tells me.

As another matter, I can argue that in the best listening room
I've seen, 18 bits would have been nicer than 16 bits if 
somebody had made the perfect digital recording, but of course
until somebody invents the mike, preamp, mix and such to take care
of such range, ...
-- 
Extremism *Copyright alice!jj 1992, all rights reserved, except transmission
   in the    *by USENET and like facilities granted.      Said permission is
  defense of     *granted only for complete copies that include this notice.
 liberty is no vice.  *Use on pay-for-read services specifically disallowed.
Xref: sparky rec.audio:17649 rec.video:15313
Newsgroups: rec.audio,rec.video
Subject: Re: Selecting an LD Player
From: cal@gsbux1.uchicago.edu (Cal Lott)
Date: Fri, 1 Jan 1993 19:42:40 GMT
 <1992Dec30.073038.14692@uhura.neoucom.edu> 
 <shetline-301292233743@128.89.19.85> <1993Jan1.014230.19891@midway.uchicago.edu> <shetline-311292221957@128.89.19.85>
Organization: University of Chicago Computing Organizations

shetline@bbn.com (Kerry Shetline) writes:
>cal@gsbux1.uchicago.edu (Cal Lott) wrote:
>  ...
>> 	Kerry, my understanding of the term "jitter" as used in "high-
>> end hype" has nothing to do with mechanical thumping and shaking.
>
>That is my understanding, too. Which is why I find claims of improved
>mechanical stability resulting in reduced jitter in a digital signal
>absurd. The Theta people want you to believe that gross mechanical
>vibration (well short of causing mistracking) will somehow manifest in the
>data stream, or the analog signal produced thereof. Only in something so
>badly designed that in would have to be done on purpose!

	Is that what *Theta* claims about the player, or *Video* claims?
Theta is highly regarded company, and mechanical jitter just isn't
something that I think they would be terribly interested in.

	On the other hand, I could see some writer or editor at Video
magazine coming up with a gross misunderstanding of jitter and then
printing it.

						-Cal
--
----------------------------------------------------------------------
Cal Lott          "Oh, I see-- I thought 'no' meant 'spoon'!" --Dan
Email me, baby!   cal@gsbux1.uchicago.edu   cjl1@midway.uchicago.edu
----------------------------------------------------------------------
From: rmp@crashnburn.Eng.Sun.COM (Richard Pottorff)
Newsgroups: rec.audio
Subject: Re: FM reception
Date: 23 Dec 1992 23:42:23 GMT
Organization: Sun
Distribution: usa
NNTP-Posting-Host: crashnburn

In article <1h4vtrINNb0j@uwm.edu> glenne@csd4.csd.uwm.edu (Neuromancer ) writes:
I am looking for a setup that will allow me to get the best
FM radio reception for a reasonably low cost.
 
Also, my stereo system along with my CD player recently died, so
I will have to buy everything _but_ speakers.  I am looking to spend
maybe only $300 for the whole setup.  I don't want anything fancy.
I just want a reliable 3 beam CD player, along with a reciever/
tuner/pre/post amp.  I don't want a tape deck or turn-table.
 
I am looking for something that will last and give me awesome FM radio
reception.  Is there anyone who can make any brand name or model
suggestions?  I am looking for CHEAP, and extremely LONG-LIFESPAN,
equipment with reasonably OK sound.    For the FM reception, should
I just buy the mushroom shaped signal booster from radio shack?
Should I run a cable to my TV antenna on my roof?  What kind 'O cable?
Are there any other nifty tricks for boosting FM reception?
 
Thanks in advance,
Glenn                       glenne@csd4.csd.uwm.edu

I jump in:

I don't know if you can meet all your criteria, and won't even attempt
to try to suggest components.

However, I will make a stab at your FM reception.  I've had really good 
luck with my TV/FM set up. I have a TV antenna on my house's roof, with
a 300 Ohm to 75 Ohm transformer. (75 Ohm cable is a little more lossy 
than 300 Ohm, but its self shielding, so proximity to metal doesn't
unbalance it (as would happen to 300 Ohm cable), and as it doesn't get 
unbalanced, it doesn't pick up stray radiation, etc.

At the end of the 75 Ohm coax, I have a 1 to 4 antenna 
splitter/amplifier, with one output going to an FM amplifier, with a FM
filter, then to my stereo, and the other 3 outputs to my TV and VCRs.  
The receiver has a 75 Ohm input, so I use that.

I get much better reception than I ever did with just the indoor 'T'
antenna hanging from my walls, and the room looks better without the
indoor antenna hanging around, too. (Of course, the exposed back of my
stereo rack looks like an electrician's nightmare, even tho I have 
dressed the power cords, and audio patch cables (in separate bundles,
of course) ).  The 4 to 1 and FM booster are from Radio Shack. I got
them several years ago, so I don't know if they are still in stock.

Rick

--
Stolen signature:
GILLETTE'S PRINCIPLE:
  "If you want to make people angry, lie. If you want to make
   them absolutely livid with rage, tell the truth."
Newsgroups: rec.audio