HDTenEightyP/NetNews huggingface dataset:
From: fuzzy@sage.cc.purdue.edu (Fuzzy)
Newsgroups: rec.audio.car
Subject: tapedeck ?'s
Keywords: comments?
Date: 9 Nov 92 22:35:50 GMT
Article-I.D.: mentor.BxH03r.M2A
Distribution: na
Organization: Purdue University


ok...here it is...i posted earlier about looking for a deck...haven't made 
it to any shops yet, but i've got an idea of what i'm looking at...
the specific models i'm currently considering are:
JVC KS-RX770..pull-out (8W/22 peak)
Kenwood KRC-3005...not a pull-out, but more power than the JVC (15W/25 peak)
Blaupunkt Boston ...not a pull-out (10W/25 peak)

anybody have any experience with these?  comments?
(i'm currently leaning towards the JVC, simply because it's a pull-out)
thanks for any info..

Fuzzy
--

Passion:  A feeling you feel when you feel you are about to feel a 
          feeling you've never felt before.

fuzzy@sage.cc.purdue.edu
Organization: Senior, Electrical and Computer Engineering, Carnegie Mellon, Pittsburgh, PA
Newsgroups: rec.audio.car
Date: Fri, 13 Nov 1992 00:15:25 -0500 
From: Amit Likhyani <al1x+@andrew.cmu.edu>
Subject: Re: DREAM SYSTEM...
	<1992Nov12.155556.18700@magnus.acs.ohio-state.edu>

Start with an Alipine 7909 CD tuner with changer control.   Add an
Alpine 5957 changer.  

For front sound stage, get Quart 328CX and tri amp it with a Phoenix
Gold 6 x 75 $75000 amplifier.  The 190 amp alternator comes with it.

Get Quart 215CX for the rear and bi amp that with the most expensive 4 x
50 amp you can find.  Try blade or Phoenix Gold.

For the Subs, get another $75000 Phoenix Gold amp.  Make 3 separate
chambered push pull Tecktonic woofers.

Get as much Audio Control shit for the center channel and cross overs.

Get about 30 1 Farad caps.

Motorize the amp rack.

Install a nintendo, video player, TV

Have Fun - that was a pretty pointless question
Newsgroups: rec.audio.car
From: sbourgeo@pinocchio.Berkeley.EDU (Stephen Bourgeois)
Subject: Re: FAQ? && Need pickup info
Reply-To: sbourgeo@pinocchio.Berkeley.EDU (Stephen Bourgeois)
Organization: Encore Computer Corporation
Date: Fri, 6 Nov 1992 17:56:04 GMT

In article <1992Nov2.172439.11160@ncsu.edu>, bcasper@eos.ncsu.edu (Brian
Casper) writes:
> 
> First, has this group developed a FAQ?  If so, could the keeper post it,
> or e-mail it to me.
> 
> Second, anybody with any experience installing a system into an S10 or
> similiar small-cab truck, I would be interested in hearing about your luck
> with speakers.
> 
> Vielen danke...
> -- 
> -- 
> Brian Casper                |   "I like to study psychologists.  It gives
> bcasper@eos.ncsu.edu        |    good insight into what rats are think
I just bought a Mitsubishi Mighty Max and manuvered
a stereo and pair of speakers into it...
Newsgroups: rec.audio.car
From: jpau@oracle.com
Subject: Alarm for carjacking
Organization: Oracle Corp., Redwood Shores CA
Date: Thu, 12 Nov 1992 00:54:59 GMT
X-Disclaimer: This message was written by an unauthenticated user
              at Oracle Corporation.  The opinions expressed are those
              of the user and not necessarily those of Oracle.

Does anyone has any suggestion for any addons to your existing alarm system
to take care of the now getting popular carjacking problem?
Newsgroups: rec.audio.car
From: rcrawfor@nyx.cs.du.edu (Ron Crawford)
Subject: Car Radio Installation
Organization: Nyx, Public Access Unix @ U. of Denver Math/CS dept.
Date: Wed, 11 Nov 92 17:06:37 GMT


 
   A few weeks ago I purchased a new car stereo. Nothing fancy, it's 
just a cheap digital job with a cassette. Basically, I just had to get
something to replace a factory standard 8-track in my '79 Buick.
 
   I'm having a helluva time installing it, and I'm not about to pay
another $75 to have it professionally done. I bought one of those radio
kits and wireing harness and still no luck. Here are the problems I'm
having:
 
  There is a big screw coming out of the back of the radio. Is this
just for support? The manual doesn't say anything about it.
 
  With the kit, the radio does not sit flat against the bottom plate.
Would it be alright to just stick something in there propping it up
to a level height?
 
Any advice would be appreciated.
 
rcrawfor@nyx.cs.du.edu
 
"Yessir, everything's standard. It'll slide right in any car." Yeah, right.
From: jmc@reef.cis.ufl.edu (Justo Casablanca)
Newsgroups: rec.audio.car
Subject: 92 eclipse help
Date: 7 Nov 92 03:20:31 GMT
Distribution: na
Organization: Univ. of Florida CIS Dept.


HI KIDS!!

got a couple of questions for you stereo experts out there..
1. what is your opinion on putting speakers in my front factory locations
5  1/4 in the door and 3 1/2 in the dash near the window.  I want to put a 2
way component system there with the tweeter in the dash but i am concerned 
about imaging. has anyone done this to a car and seen what has happened??

2. should i put 6 1/2 or 5 1/4 in the front locations?? i am planning on 
adding a subwoofer soon .. I heard that putting to large a speaker up front
slows down the sound ??

thanks for the help
dan
.
Newsgroups: rec.audio.car
From: norcott_bill@tandem.com (Bill Norcott)
Subject: Re: add CD player to NISSAN Maximum ?
Reply-To: norcott_bill@tandem.com (Bill Norcott)
Organization: Tandem Computers, Inc.
Distribution: usa
Date: Wed, 11 Nov 1992 20:00:55 GMT

In article <1992Nov11.175328.4402@qualcomm.com>, pyuen@qualcomm.com (Patrick Yuen) writes:
|> I have a '91 240SX with the factory radio and have been watching
|> this "add a CD" thread with interest.  How much should I expect to 
|> pay for this wiring harness?  Do I just call the dealer and say

J.C. Whitney sells harness kits for Nissan and other makes, they
cost $6.95 + shipping.

-- 
---------------------------------------------------------------------|
Bill Norcott			GUARDIAN POSIX project
Tandem Computers, Inc.		
10600 N. Tantau Avenue		PHONE:  (408) 285-3253
Cupertino, CA   95014		EMAIL: norcott_bill@tandem.com
From: st1q9@rosie.uh.edu (Devine, Della M)
Newsgroups: rec.audio.car
Subject: 1 Farad Capacitor availability
Date: 11 Nov 92 17:09:00 GMT
Article-I.D.: rosie.11NOV199211095879
Organization: University of Houston
News-Software: VAX/VMS VNEWS 1.41


   Right now i'm looking in the new Pasco Scientific Physics catalog and
they have for sale a 1 farad capacitor for roughly $19.00.
The problem is is that it is a 5 volt and not a 12-20 volt as needed for
automotive use.  Does anybody have any idea how to get a 5volt to work
with 12-15 volts?  If so then these would be a lot cheaper than the
800,000 microfarad that 2000 sells for $125.00...

                                   William C. Devine, II
reply to: Devine@pvhep.pvamu.edu
From: hhtra@usho21.hou281.chevron.com (T.M.Haddock)
Newsgroups: rec.audio.car
Subject: Re: Car Stereo Competitions
Date: 5 Nov 92 23:20:24 GMT
Organization: Chevron

In article <92310.115633MMJ106@psuvm.psu.edu>, MMJ106@psuvm.psu.edu writes:
|> Hi.  I just wanted to inform everyone who is into systems that there are car
|> stereo competitions.  Anyone can enter.  For more information, contact SOUND
|> WAVES, Car Audio and Alarms.  They have participated in many of these events
|> and have received many tropies.  They are located in West Chester and
|> Norwood, PA.  Both stores are not far from Philadelphia, King of Prussia,
|> and Lancaster.  They are also not too far from New Jersey, Delaware and
|> Maryland.  They also build competition installs and have cars for you to
|> listen too.  Call--(215) 696-1447.  They will be happy to hear from you.
|> Maybe you can visit their store or even attend a stereo competition with
|> them.  It is fun.  Give them a call and let them know what equipment you
|> have or what you want.  --MJ.

 Man, what a great idea!  Wish I'd thought of that!  :)

 If I did, I'd probably call it...  IASCA!

 Yeah, that's the ticket!  :)

 Thanks, guy.
From: kmr4@po.CWRU.edu (Keith M. Ryan)
Newsgroups: rec.audio.car
Subject: Re: Alarm for carjacking
Date: Thu, 12 Nov 1992 15:44:16 GMT
Organization: Case Western Reserve University
NNTP-Posting-Host: b64746.student.cwru.edu

In article <1992Nov12.005459.24362@oracle.us.oracle.com> jpau@oracle.com writes:

>Does anyone has any suggestion for any addons to your existing alarm system
>to take care of the now getting popular carjacking problem?

	I forgot one more method, but the individual has to decide how '
brave/stupid' they are.
	If you are at an intersection, it's called flooring it. Most car 
theives do not want to kill someone, and they may hesistate on firing. A
car theft is now common, and for the most part, loosely investigated. But, 
a murder brings more attention. However, it's a risk one must take. Nothing 
is certain.
From: jphillip@comanche.ess.harris.com (John Phillips)
Newsgroups: rec.audio.car
Subject: Re: Amp problem (I think)...
Summary: troubleshoot
Date: 11 Nov 92 02:16:04 GMT
Reply-To: jphillip@comanche.ess.harris.com
Organization: Harris Corporation, Government Aerospace Systems Division

>For the last week, my right rear 6x9 has been barking during
>all mid-bass hits, so, I isolated all the speakers on that channel
>of the amp and found that not only did my 6x9 distort but also
>my 5 1/4's and my tweeter.  So, it has to be the amp.  My question
>is what does it sound like and how much can I expect to be robbed
>of to fix it.  It is a Punch45.  Thanks.

Sounds like a problem in the amp, but just to be sure you should
troubleshoot by switching the RCA inputs.
From: jeh@cmkrnl.com
Newsgroups: rec.audio.car
Subject: Re: Capacitors, etc... CALMLY
Date: 10 Nov 92 19:32:16 PST
Organization: Kernel Mode Consulting, San Diego, CA

In article <gilchr.721386805@ee.ualberta.ca>, gilchr@ee.ualberta.ca (Andrew Gilchrist) writes:
> Now, if the series inductance of the capacitor is large, as it is with
> large electrolytics, due to the nature of their construction (rather like
> two big flat coils), the capacitor will also tend to resist sharp current
> changes through is.  [...]  So, we stick in a smaller capacitor with a much smaller
> series inductance to supply current for overly sharp current demand
> changes (high frequency demands).  Obviously, this requirement depends
> largely on the inductance of the large capacitor, and the nature of the
> load.  i.e. your mileage may vary.

Yup.  All of this exactly corresponds to the practice of using small bypass
caps (typically 0.1 uF) near TTL chips, with a few uF worth of tantalum
capacitor for each circuit board.  When TTL outputs switch they cause a very
brief (but easily visible on a scope) noise spike in the power supply rail. The
big capacitor in the power supply has too much inductance to deal with these
high-frequency spikes.  (In physically large systems involving many circuit
boards, etc., the power supply cap will also be separated from the load by a
non-trivial length of wire, which adds inductance of its own.) 

However, I am dubious about the application to car power amps, especially 
high-power ones.  

The reason I'm dubious is that these power amps do not run directly from the
12V (oh, all right, 13.6V) input.  Instead they have a DC-to-DC converter.
Without this you can't get more than about 18 W RMS continuous through a 4-ohm
load without distortion. 

	(A bridged amp running directly from the 13.6 V supply has a peak-to-
	peak output of about 24 V, assuming very low-resistance devices in the
	output stage.  This equates to about 8.4 V RMS, or about 18 Watts RMS
	into 4 ohms.)

So these add-on capacitors are not really filtering (or removing HF noise from)
the voltage that's supplying the amp's output devices.  They're separated from
the output devices by the amp's power supply.  Also, it is worth mentioning
that the amp's power supply has its own filter caps.  These will tend to be
smaller capacitances (hence lower inductance) than we'd typically see on the
output of a linear power supply, since the amp's DC upverter typically runs at
supersonic frequencies rather than 60 Hz. 

Has anyone actually measured the output of a high-power car audio amp, with and
without various additional capacitors on the 12V supply, to see if they make a
difference?  How about putting a scope on the amp's internal supply rails?  Or
even the 12 V supply to the amp?  The "high frequency noise" that we're looking
for is limited to audio bandwidths, so it shouldn't be THAT hard to see...

	--- Jamie Hanrahan, Kernel Mode Consulting, San Diego CA
Internet:  jeh@cmkrnl.com, hanrahan@eisner.decus.org, or jeh@crash.cts.com
Uucp:  ...{crash,eisner,uunet}!cmkrnl!jeh
Newsgroups: rec.audio.car
From: trw@spl1.spl.loral.com (Tim R Witort)
Subject: Re: Suitable Capacitor?
Organization: Loral Software Productivity Laboratory
Date: Fri, 6 Nov 1992 17:12:16 GMT

In article <gilchr.721043941@ee.ualberta.ca>, gilchr@ee.ualberta.ca (Andrew Gilchrist) writes:
|> kmr4@po.CWRU.edu (Keith M Ryan) writes:
|> 
|> >	I thought the topic was external capacitors, e.g. on the 12 volts DC 
|> >line. In that case, having an higher frequency impedence would actually help 
|> >keep alternator whine and the like out. I can fully understand the need for 
|> >such on the internal capacitors for the switching supplies, but for pure DC?
|> 
|> AAAAAAAAAARRRRGGGGGGGHHHHH!
|> YOU PUT THE CAPACITOR ACROSS THE POWER RAILS.  FROM +12V to GROUND.
|> Got it?
|> If you have a large series inductance with the capacitor, the high
|> frequency components will NOT be absorbed by it.
|> 
|> If you put a cap in series with the 12V line, it will not pass anything
|> BUT high prequencies. i.e. NO POWER.
|> 
|> You people.

   Pardon me, your majesty, but if I may be so bold as to
intrude on your most justified tirade against us lowly stupid
peons... lighten up.

-- Tim
From: walkerr@bigwpi.WPI.EDU (Robert A Walker)
Newsgroups: rec.audio.car
Subject: capacitors
Date: 9 Nov 1992 15:08:04 GMT
Organization: Worcester Polytechnic Institute
NNTP-Posting-Host: bigwpi.wpi.edu

Does anyone out there know what size capacitor i should use to cut out 
the frequencies below about 100 or 200 htz?
From: milo@dorm.rutgers.edu (james mielo)
Newsgroups: rec.audio.car
Subject: subs with specific specs
Date: 6 Nov 92 00:42:13 GMT
Followup-To: rec.audio.car
Organization: rutgers university

I'm looking for a subwoofer. It can be either an 8",10" or 12" with the
following general specs. 	
              1- a low Vas
              2- high Qts
										    3- free air frequency response of about 30 Hz
I know these are very general parameters. However, I'm not certain what my
box design will be or for that matter what my set up will be (ie four 8"s
two 10's or one 12)  I'm looking for somewhat high end stuff for possible
competition at a later date but not too expensive. If you know any speakers
with these parameters please send me your suggestions 

																						Jim
From: kmr4@po.CWRU.edu (Keith M. Ryan)
Newsgroups: rec.audio.car
Subject: Re: Capacitors, etc... CALMLY
Date: Fri, 13 Nov 1992 19:10:00 GMT
Organization: Case Western Reserve University
NNTP-Posting-Host: b64746.student.cwru.edu

In article <83060002@hpsgrt1.sgp.hp.com> philip@hpsgrt1.sgp.hp.com (Philip LOH) writes:
>I used to have those Infinity Kappa CSI component speakers in my
>car and the instruction given by the manufacturer is :"Never
>connect the mid and high direct to the amp output."   You
>have to connect the passive crossover between the amp and the
>speakers.  I am now adding an active cross-over (electronic
>crossover SONY XEC700) to the system.  Reason being that I 
>am adding in more amps and speakers.  I am planning to use
>dedicated amp for each of those speakers.  Do I still need
>to obey the manufacturer's instruction of putting the 
>passive crossover in ? What's going to happen if I do not ?
>am adding in more amps and speakers.  I am planning to use
>Please advise.

	The main reason why you need to have the passive crossover was to 
block the bass from the speakers, so they would not blow. The tweeter would 
easily fry, and the power handling of the midrange would be greatly 
diminished.
	If you have appropriate active crossover frequncies, there ought not 
to be any problem. Try to use a similar COF for the tweeter and midrange, if 
possible

	Note: I believe the CS1's used a low impedence Emit-n ribbon 
tweeter. I would check the impedence of the tweeters, as if they are the low 
impedence variety, the crossover module may have additional resistors to 
increase the impedence, and you may need an appropriate amplifer able to 
drive the lower impedence. [ note: I am not sure about this, as I've never 
actually used the CS1's myself]
Newsgroups: rec.audio.car
From: gilchr@ee.ualberta.ca (Andrew Gilchrist)
Subject: Re: capacitors
Organization: University Of Alberta, Edmonton Canada
Date: Fri, 13 Nov 1992 06:58:29 GMT

genocide@hale.cts.com (Gary Danko) writes:

>walkerr@bigwpi.WPI.EDU (Robert A Walker) writes:
>> In article <gilchr.721389283@ee.ualberta.ca> gilchr@ee.ualberta.ca (Andrew Gi
>> 
>> >That gives your -3dB points at 100Hz and 200Hz respectively (approx.)
>> 
>> 	Please excuse my ignorance, but what exactly does -3db mean, what does
>> -12db mean, which one is better, or is it a matter of personal preference,
>> I know what a db is but i though that the more decibles (sp?) the louder it
>> was,  am i lost or what?  

>i missed the original message but 100hz is a low freq range for speakers. 
>db gain is better if higher. my fosgates get about 91db.

You should read the original post before publicly uttering things like
this.  It is clear you have NO idea what we're talking about.

The 91dB (dB damnit!) you are referring to is dB/W@1m, meaning the
on-axis SPL generated by the speaker at 1meter distance with a 1 watt
input in a anechoic chamber. The frequency of the input is usually specified
as well.

Andrew
Organization: University of Illinois at Chicago
Date: Friday, 13 Nov 1992 11:20:08 CST
From: <U60535@uicvm.uic.edu>
Newsgroups: rec.audio.car
Subject: Re: DREAM SYSTEM...
 <1992Nov12.155556.18700@magnus.acs.ohio-state.edu>
 <Uf0nbha00Vpc0Ds0wB@andrew.cmu.edu>

DREAM SYSTEM?  SOUNDS LIKE A NIGHTMARE.  GO TO KRELL IDUSTRIES AND TELL THEM
WHAT YOU WANT.  THAT WOULD BE A DREAM SYSTEM! THEY WOULD DESIGN SOME KILLER SHI
T!
From: jkaegi@gmuvax2.gmu.edu (John Kaegi)
Newsgroups: rec.audio.car
Subject: Recommandations: 5 channel amps
Keywords: Setup with 1 amp w/ built-in x-over.
Date: 12 Nov 92 23:38:14 GMT
Organization: George Mason University, Fairfax, Virginia, USA


	I want to upgrade add rear speakers to my car and figured
I'd get an amp with a crossover.  I would to keep it simple so
I figured something like a Soundstream MC245 to power everything
I'd "eventually" put in it.  The problem is that no one around
here carries it, Circuit city has the MC120, so I'm debating
if I want to go with a 4 channel amp and loose my fader.  I'm
leaning toward a Sedona (sp?) 4 channel w/ x-over.  Any ideas/opinions
are appreciated.
thanks,
 john
jkaegi@gmuvax2.gmu.edu
From: gt0869a@prism.gatech.EDU (WATERS,CLYDE GORDON)
Newsgroups: rec.audio.car
Subject: Re: Solobaric Subs: Anyone using them?
Keywords: solobaric
Date: 9 Nov 92 14:49:24 GMT
Organization: Georgia Institute of Technology

In article <bublitz.721165233@sfu.ca> bublitz@fraser.sfu.ca (Martin Bublitz) writes:
>So with all this talk about the Kicker Solobaric subs, is anyone out there using
>them??  What do you think of them??  Even though they take up minimal space, how

MAN what a WOOFER!!! I just put in a set of S-10's in a 300zx turbo using a
HiFonics Hercules as power- they seriously threw down! HOWEVER--- totally
disregard the trash Kicker sends with the Solobarics about using them in
only sealed enclosures (under .66 ft^3 for the 10's, etc)! The pair I used 
are in a box designed on a computer, which came out .86 ft^3 ported @ 29
Hz, with boost of 6 dB at 29. I can clip the Hercules (375 watts !!!)
into the S-10's at any frequency tried without audible protest; they 
don't even move much near port frequency, so mechanical damage is not
going to be a factor either. As for the sound, they put out bass comparable
to a good pair of 15's in a BIG box, only as tight as some of the best 10's.
I would say that in the configuration I used, the S-10's can put out more
and lower frequency bass on the same power than C-12xl's currently available.

Moral of story: they are expensive, but they are better.

Regards,
Gordon.

-- 
WATERS,CLYDE GORDON-Class of '93-Georgia Institute of Technology Atlanta Ga. 
"Out of the mountain of despair, we can hew the stone of hope"- MLK Jr. 
uucp:	  ...!{decvax,hplabs,ncar,purdue,rutgers}!gatech!prism!gt0869a
Internet: gt0869a@prism.gatech.edu
From: kmr4@po.CWRU.edu (Keith M. Ryan)
Newsgroups: rec.audio.car
Subject: Re: Alarm for carjacking
Date: Thu, 12 Nov 1992 15:40:10 GMT
Organization: Case Western Reserve University
NNTP-Posting-Host: b64746.student.cwru.edu

In article <1992Nov12.005459.24362@oracle.us.oracle.com> jpau@oracle.com writes:
>Does anyone has any suggestion for any addons to your existing alarm system
>to take care of the now getting popular carjacking problem?

	Currently, there are not many safe methods of protecting oneself. 
Carjackers usually strike while the car is running, and any alarms 
deactivated by the owner. In the age of more and more sophisticated alarms, 
it makes sense, from the robber, to steal the car after the alarm is off. 
Here are some ideas that I have heard of, but all are potentially dangerious 
to the owner. I doubt that many people want to get into a gunfight with the 
theif...

	Install a peircing siren inside the cab, maybe under the dash. The 
on/off switch can then be a remote one carries in one's pockets ( not on the 
key chain ). That way, when you're thrown out, and the guy is driving away, 
you can then activate the siren. However, if it is loud enough to cause 
physical pain, rather than mild discomfort, he may end up totalling your car.
And, it can easily backfire, and go off when you are driving.

	Install a electrical kill system, with a remote on/off. After the 
theif begins to drive away, you push your remote button. You can have a 
delay, as you want to arm it while the car is still  close, but you don't 
want the car stopping 20 feet away from you! However, if the car suddenly 
shuts off, it may be uncontrollable, and the theif may total it. This can 
also backfire against the driver.

	The above may be illegal in some states. I believe it is illegal to 
have an ignition kill switch in FL, but may be wrong.

	Hey, what about the car alarm in Robocop? :-) fry sucker, fry!

	You can always arm the regular alarm, so the car will have its 
lights blinking, and siren blaring away. Hopefully, a nearby cop car will 
see it.

	Other than that, you may get a lo-jack system. In any event, you'll 
just have to pray that when they find your car, that it is recognizable.
From: kmr4@po.CWRU.edu (Keith M. Ryan)
Newsgroups: rec.audio.car
Subject: Re: DREAM SYSTEM...
Date: Fri, 13 Nov 1992 17:35:53 GMT
Organization: Case Western Reserve University
NNTP-Posting-Host: b64746.student.cwru.edu

In article <92318.112008U60535@uicvm.uic.edu> <U60535@uicvm.uic.edu> writes:
>DREAM SYSTEM?  SOUNDS LIKE A NIGHTMARE.  GO TO KRELL IDUSTRIES AND TELL THEM
>WHAT YOU WANT.  THAT WOULD BE A DREAM SYSTEM! THEY WOULD DESIGN SOME KILLER SHI
>T!

	Seriously, how would you ever practially use any Krell products in 
the car ( unless you want a LONG extension cable )? I would absolutely love 
to put one Mc1000 as a subwoofer amp ( I'll love being able to afford doing 
that even more! ) 1000 watts mimimun RMS/ch into 8 ohms! { as Mc is so 
conservative in their ratings, it probably is closer to 1200 or so. }
And, we arn't talking about limited dynamics or imprecise soundstaging here, 
common to most of the large car audio amplifiers. And, it's big, very very 
big. But, where are you going to find a DC to AC converter which can supply
50 A at 120 V ac?