Conference hips::uk_audioo

That seems pretty wierd.

I think that you can safely say that there is something in the cassette recorder
that is interfering with the blip sound.

With Cassette Recordings, the input is modulated onto a high frequency bias
signal. The voltage of the bias signal is that which is altered when you choose
Normal, Chrome or Metal.

Perhaps it is interfering with this, although I don't think it should.

The other possibility, if your cassette deck has automatic level control, is
that the blip is fooling it into lowering it's level. Does the music stay quiet
for about � a second after each blip ? That is what I'd expect if it were the
automatic level control.

If your cassette recorder has automatic level control, I'd be inclined to change
it as this can remove all the dynamics in some music.

If your cassette recorder doesn't have automatic level control, I'd be inclined
to test record onto another one, to see if you get the same effect.

Mark.

    The cassette recorder does not have ALC.  It's a Dennon DM600.  
    I've tried recording the lp on a cheap Phillips "sound machine" which
    has ALC, and the problem isn't there.  The Phillips also has very limited
    low frequency (and high frequency) response, so the blip probably doesn't 
    get through its amplifiers onto the tape.  I guess that the blip
    frequency is about 20-30 hz.
    
    I've also tried on a Sony recorder about 10 years old.  Its frequency
    response is also limited but less so than the Phillips, and the effect 
    is there but not very strong.
    
    The Dennon has 20-20k response, so the blip frequency is within the
    range.  The Dennon also determines the tape type (and bias) automatically 
    by recognizing the characteristic holes in the plastic cassette.
    
    

re .0:

I've had similar problems in the past.  What I found was that the signal
generated by the record warp was considerably higher in amplitude than the
music signal.  It was made up of the initial warp plus a nasty arm/cartridge
resonance (that not all warps excited).  If you watched the speaker cone, you
could see it going in and out rather a long way.  This is fine if the
cartridge, preamp or tape deck between them filter out this signal.  However,
if they don't, it can saturate the record amplifier, whose clipping makes
pretty disgusting noises on the tape.  Before this point, I guess this would be
where you get mixing:  the record amps are operating in a non-linear region.

I first noticed it when I changed over to using a 'real' preamplifier as
opposed to the home-built jobbie that deliberately filtered this stuff out.  My
solution was to use various silly ways of damping/moving the resonance, and to
record warped records at a lower level, so the record amps didn't approach
clipping.  Not a perfect solution but I don't have many warped records.  If
your problem can't be cured this way I imagine only a filter between preamp and
tape deck will help; but I've never seen such line-level filters commercially
available.

Nick

re .0:

ass uming you've paid the licence fee to do what you describe (and surely you
aren't breaking the law ... shame on you :-)) then contact the Mechanical
Copyright Society (their address is on your licence) - they have a technical 
advice office that can help...

/. Ian .\

re .4:

I find your comment offensive (and yes, I did see the ':-)'). Just because
someone's taping an LP doesn't mean they've got a licence to do so.  I hold no
such licence and feel perfectly justified in making copies of my own LPs to
play in my car.  I am quite happy to admit to this, and would defend my right
to make such copies.  There are valid performing-rights concerns regarding
taping records but you'll do the performers' cause no good if you adopt a
position that is clearly absurd.  Please limit snide comments to those engaged
in something that can be reasonably regarded as theft, such as those who tape
*other peoples'* LPs.

Nick

    re .5...
    
    I don't find .4 snide, just tongue in cheek. Also accurate, if somewhat
    off the point.
    
    UK laws on this aspect of copyright do *not* give you the right to tape
    your own records for your own use - yet. Although you own the plastic,
    the artistes and the record companies own the intellectual property
    represented by the music you bought the album for. The law is almost
    impossible to police, but that doesn't change the fact that in essence
    home taping is illegal. Of course you have a right to choose whether or
    not you obey the law, but declarations of intent to do break it are not
    consistent with company policy on the use of Notes.
    
    I have no wish to see this conference zapped because the users don't
    stick to the rules. Please, let's get back on to the subject.
    
    Dave (co-mod)

    Re. .4,5,6
    
    I didn't open this rathole, but I'd like to close it.
    
    I don't live in the U.K., so its laws don't apply to my situation.
    I'm trying to tape MY records for MY OWN use, since the records in
    question are rather old and haven't been reissued.  If the record
    companies marketeers choose to manage their profits by not reissuing the
    records I like, neither in the LP, cassette or CD formats, then the
    only way I have of ensuring my continuing pleasure in hearing them is
    to make my copies.  If I'm forced to choose between the profits of the
    record company and my enjoyment, there's no question of my being
    altruistic.
    
    <end_rathole>
    
    Concerning the original problem, it would appear that a sort of rumble
    filter is necessary here.  I'll build one this weekend and try it out.
    I only hope that it won't appreciably reduce the excellent frequency
    response of the cassette recorder.
    
    Thanks for your help and suggestions.
    
    David

Moderator thank you:

This is a UK audio conference so I didn't bother to check whether the noter was 
in the Uk.

The Mechanical Copyright Society is an arm of the performers and writers, not 
the record companies. The law is the law, regardless of how stupid it is.

Finally it is a fact that the Mechanical Copyright Society offers technical 
assistance to those who hold licences.

/. Ian .\

    RE: .7
    
    Why don't you use Grant's Equaliser, I don't think he'll ever let
    it back in the same room as his set-up again!
    
    Robert.

    	Hello,
    
    	I suggest you try with a filter, cutting sharply below
    	40Hz with 12/18 dB/octave. (Also known as "rumble" filter.
    
    	Here the reasons why: 	
    	Your "blip", if you could mesure it, may by far exceed the
    	average amplitude of your record, however beeing of quite 
    	low frequency (down to some Hz) you just do not "hear" it.
    	Also your VU-meters may bee to 'slow' to "show" the 'blip'. 
    	Try to remove the speakers front grill, you will see the
    	woofer's membrane moving SOME centimeters, although the
    	listening level is low. I have seen speakers go broke, 
     	amplifiers with blown fuses, and trouser's flapping 
    	because of that.
    	
    	What's happening whit your tape recorder is that he will try
    	to  put that very low frequency blip onto tape. However,
    	beeing of such short, but enormeous amplitude, it will 
    	completely saturate your recorder, and you get the feeling
    	of 'modulated' music, which is the classical behaviour of
    	extremely saturated amplifiers/tape recorders. 
    
    	Using a filter may cut your blip down to a level allowing
    	a correct recording, but your music quality will not suffer.
    	I remember many years ago, when working for STUDER, I've
    	seen recordig studios cutting everything below 40Hz and the
    	sound was still VERY good.
    
    	Wondering wheter you will now be able to record your tapes,
    
    	     Toni.
    
    	Let us know wheter a filter did help