Conference napalm::commusic_v1

	I use a Radio Shack Demagnetizer wand. About $15.

	It looks similar to a soldering iron. You plug it into the
	wall, and carefully move the long magnetized tip over the heads 
	a few times. Complete instructions were included.

	I've used it on a fostex X14 4 trk, an Onkyo, 2track cassette,
	and even on sony walkman type decks..

	Very simple, unless the heads are hidden by out of the ordinary
	doors or other such obstructions. The number of tracks makes 
	no difference, 	so as long as you can get the tip within a 
	millimeter of so of the head, it will work fine.
	I'd guess I could probably even get it into my car deck.
	
	Since it is magnetized, you have to turn off the deck, and
	must keep it away from any tape you want to keep.

	Can't comment on the (in the cassette) demagnetizers, since
	I've never used one. Obviously you could not use it to demagnetize 
	your 1/4" four or 8 track, as you could with the radio shack variety.
	
	Buy the way, I've noticed dramatic improvements after using it.
	Well worth $15 or so.

Rick

    
    	What are the symptoms you see when you need a tape player 
    demagnetized?
    
    ED

    < Note 2012.2 by MUDDIN::DEBARROS >
>What are the symptoms you see when you need a tape player 
>demagnetized?
>    ED

    The highs on your tapes start to go away.
    
    karl

    Yo, Eric.
    
    I've got a de-magger. (nothing worse than losing your highs, ya know?)
    
    Takes quite a while to do. Probably blow the best part of 15 seconds.
    
    Stop by and get it....
    
    Edd

    Paper clips stick to it.
    
    len.
    

    it starts to act like a saturable reactor

    the stuff you recorded a year ago starts sounding good again ...

    
    	the magic wand even works from a distance of 1" or so too if
    you can't get in real close. And a fast way to erase that bad track
    also ;-)

>    the stuff you recorded a year ago starts sounding good again ...
    
    In that case, I may never demag my heads.

    > I may never de-mag my heads.
    
    You may never have to!
    
    ;^)
    
    Edd (Appreciative of "Lo-Cal Blues")

>>>    the stuff you recorded a year ago starts sounding good again ...
    
>> In that case, I may never de-mag my heads.
    
>    You may never have to!
>    Edd (Appreciative of "Lo-Cal Blues")
    
    Well, if you were wondering why the LC blues haven't shown up on
    a Commusic tape, it must be because I recorded that less than a year
    ago.  ;-)

    I think I messed up royally. After cleaning and demagatizing the
    heads of my Porta One, I plugged the the headphones in turn the unit
    on and I could not believe the hissing noise that was coming from the
    machine. This ithw the headphone volume turned all the way down.
    
    It does'nt matter if a cassette is in the machine or not. Anyone
    out there have any idea what I did wrong?  Did I pass the demagnetizer
    over the heads too fast? Did sc#?w up the heads? I made sure I turned
    the demag. (which is a $49 unit) on and off at least two feet from the
    machine. I did not even let the plastic tips touch the heads.
    
    Any and all help appreciated.
    
    Errol(who_is_new_to this_conference)
     

    Are you sure the recorder was off when you demagged the heads?  If
    it wasn't, you could easily have fried just about everything in
    the playback electronics.
    
    len.
    

	Hope it's still under warranty!  If you had the deck powered off
	when you demagged it it may just be a coincidence that your
	preamps mutated into white noise generators...  all four of 'em
	at once...  Yeah... 

	Do you know how to solder?

	It "snows" even when the volume is turned all the way down?  Do
	the line outputs show the same symptoms?

    On the bright side, it may be coincidental. Unlikely, but possible.
    
    I've demagged heads before on powered machines. Not smart, but not
    necessarily fatal....
    
    Edd the Lucky

    
    Thanks for the reply Len.
    
    The power cord was not connected to the machine.  I called one of
    TASCAM repair centers and the person there did not know if
    the symptoms I described necessarily meant the heads were ruined.
    SO the big question is there some way of knowing definitely besides 
    taking it to the repair?
    I can still record on all the tracks. 
    
    Errol (who_can't_afford_to_shell_out_$200_for_repairs)
    

It sounds to me like your demagnetizing backfired, and you ended up 
*magnetizing* your heads even more than they were before. If the power was 
off, you couldn't have fried anything. Evidence to support this is that you 
can still record on all tracks. Perhaps you didn't use a proper procedure 
when attempting to demagnetize the heads. Or maybe your demagnetizer was/is
defective. I'd say try it again using a different demag unit (if you can).

Mike D

    
RE: .14
    
Yes,it snows when the volume is turned all the way down, this is with 
no tape in the machine. 

The line outputs show the same symptoms. Engaging and dis-engaging
DBX has no effect with headphones volume on zero, but does at 
higher settings. 

Yes ,I know how to solder. But what did I break that needs soldering?
Resistor? Capacitor? I know absolutely nothing about that stuff.

RE: 18
Demagnetizer backfired?
A possibility. I will try with another demagnetizer. 

Thanks for all the help guys.

Errol

Yes,it snows when the volume is turned all the way down, this is with 
no tape in the machine. 

	OK, this really limits the scope of the problem to points in
	the signal path before the headphone amp: heads, wires, &
	pre-amps.

The line outputs show the same symptoms. Engaging and dis-engaging
DBX has no effect with headphones volume on zero, but does at 
higher settings. 

	The change with DBX is most likely a red herring.  Probably
	you're just better able to hear the effect better at higher
	levels (Fletcher-Munson, etc...)

Yes ,I know how to solder. But what did I break that needs soldering?
Resistor? Capacitor? I know absolutely nothing about that stuff.

	On the off-chance that the machine was powered during the
	procedure I was prepared to suggest replacing the pre-amp ICs
	and re-aligning the deck.

RE: 18
Demagnetizer backfired?
A possibility. I will try with another demagnetizer. 

	This is a good idea!  It doesn't cost anything and it can't
	make things any worse.  Even using the same demagnetizer again
	(assuming it works, can you move a screwdriver with it?) on a
	different path might help.

	I know it's tough to do, but maybe you could describe in detail
	the way you demagged this deck, including when you powered on the
	demagnetizer and the path you made through the transport?

    Regarding trying to demag again - I recall reading someplace that
    once a head's been magnetized inadvertantly, it's just about impossible
    to get the residual magnetic level down to an acceptable level.
    I know this is a really depressing prognosis, but I just thought
    I ought to warn you.  *If* that's in fact what went wrong.
    
    Does anybody know for sure what a magnetized head sounds like?
    
    len.
    

	It's not so much what "magnetized" heads sound like but what
    they DO that's the problem.  A tape head which has built up too
    much residual magnetism will basically erase the highs from any
    tape passing over it.  In effect, you have a kind of low-pass filter
    which permanently ruins anything that is run through (or past) it.
    
    	I've had this happen to me in the past, and it has made me very
    scrupulous about keeping heads clean and de-magnetized.  Along those
    lines, I was not aware that you could damage the CIRCUITRY by having
    your machine ON while de-magnetizing.  Many manufacturers caution
    that you could damage VU METERS and of course your speakers because
    of transients.  However, many cassette-type demags REQUIRE your
    machine to be ON to activate the mechanism. (I am thinking of TDK's
    unit, in particular.  To use this in a car stereo, you can't get
    the unit to "eat the demagnetizing cassette" unless it IS on).  I
    routinely demag my home and car cassette players, and have usually
    had them on when I did so, although always with the precautions
    mentioned above.
    
    	Erroll, I'm not an electrician, but it sounds like you may have
    some other kind of problem which may only tangentially be related
    to your demagnetizing your 4-track.  
    
    Wish I could offer you more help,
    Bill Allen     

    It's funny that this should happen to me. Because before attempting to do
    any maintenance, I read notes #2012 and #2063, a Keyboard article
    on maintenance and the Porta One user manual. I was well aware what 
    could happen if I screwed up so this is what I did.
    
    I unplugged the tape and took it to an area where I has a work light,
    I turned on the  the demagnetizer aprox. 2 1/2 feet from the tape
    and move it slowly towards the tape recorder. I then made about four
    vertical strokes (relatively slow) on each head and the capstan shaff,
    then I slowly removed the demagnetizer from the tape recorder and
    turned it off, again  approximately 2 1/2 feet from  the tape recorder.
    The whole process probably lasted about half a minute. The demagnetizer
    was was in the area of the head for about 10 to 15 seconds.
    
    That is the procedure I followed. Prior to that I cleaned the heads
    with TEAC head cleaning fluid and Q-tips.
    
    Errol
     
    made sure I turned the demagnetizer

	Your procedure reads flawlessly.  Soooo, I'm willing to bet that
	your demagnetization efforts are not the cause of your current
	problem.

	If you put a tape (nothing valuable, though) in this deck and play
	it back do you hear anything?  Is it at the normal playback level
	or is it very soft?  Is there any chance this deck got subjected
	to a static discharge while you were moving it?

    If you get noise from the outputs even with the volume *down*,
    then the problem is *after* the volume control circuits, not
    before.  Therefore the heads have nothing to do with it.
    
    The problem is more likely a fried amplifier later in the chain.
    Do you have the service manual for this thing?

    Is the noise only in the headphone output?  Or does it also appear
    at the stereo output?

Ogg !  I just bought a demagnetizer and was going to attack my beloved
Porta-1 tonight !  Someone please tell me they've done this without
problems..
						-Jeff

    Did you physically touch the heads with the demagnitizer?  I've heard
    that doing so will damage (magnetize) the heads.  But I've never
    touched heads when demagging them, so I can't verify the correctness
    of the assertion.

    -jim

    This operation is completely safe as long as you follow the directions
    religously. NEVER turn thr degausser on or off within range of the
    heads (usually 4 to 6 feet). Move the degausser tward and away from
    the heads slowly (it should take you 10 to 15 seconds to go the
    safe distance. Degaussing only takes a few seconds and all metal
    patrs in the head area should be degaussed. Do NOT touch the head
    with the degausser as it MAY damage the heads. Usually they have
    a rubberized coating on them to prevent actual contact thus to 
    prevent damage. Safe, simple, done in under a minute! 
    
    Jim
    

    
      I have demagged my PortaOne with a Shack demagger with no problems.
    As long as you do it right, it should be a piece of cake.
    
       Bob

Thx.