[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference hips::uk_audioo

Title:You get surface noise in real life too
Notice:Let's be conformist
Moderator:GOVT02::BARKER
Created:Thu Jul 28 1988
Last Modified:Mon Jun 02 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:550
Total number of notes:3847

236.0. "CD to car cassette problems" by ELIS::KEW (Jerry Kew @JGO 889-9327) Fri Nov 30 1990 13:01


I recently bought one of those dummy cassetes which takes a feed from the 
headphone outlet on a CD player, and fools your car cassette player into 
thinking it's playing a cassette.

The hum is awful, even if I just plug the cassette into the car player and 
don't plug in the headphone jack.  Has anyone else encountered this?

Jerry
PS it's hard to go back to the shop to complain as I bought it in another 
country.
T.RTitleUserPersonal
Name
DateLines
236.1Try thisLEMAN::ZILIOTTISat Dec 01 1990 17:5637
    Hello Jerry,              
    
    	Having installed different systems in my car, I did have 
    	similar problems, particularilyy when trying to match
    	different brands of HI-FI together.
    
    1-	Usually, the major problem is grounding. Have you used REALLY
    	the same ground to connect your CD-Player? The ground of the 
    	Cigarette lighter is NOT the same. Connect the player ground
    	onto the SAME wire which connects the radio ground. Also, the
    	"+" wire of the cigarette lighter may be more noisy then the
    	one of the radio.
    
    2-  If your CD player is not connected through the cigarrette 
    	lighter, connecting the CD ground with the radio ground may 
    	help. The reason for that is that the cassette magnetic head
    	has a very low signal output, and the preamplifier is very
    	sensitive. 
    	Introducing your dummy cassette, is like connecting an antenna
    	to the preamd/head, picking up noise.
    
    3-  If your CD-Player is connected through the cigarette lighter, 
    	this may bring car noise (ex: ignition) to your CD player. To 
    	identify the problem, power your CD with batteries. If now the 
    	problem disappears, you need a filter between your CD and 
    	lighter (It might be expensive (~20$) has 3 wires and is heavy.
    	Filters with 2 wires are light and less expensive (~5$), but
    	most of the time not enough efficient. You may experience the 
    	same problem although you did following advice 1-. 
    
    4)	Sell your dummy cassette (it may work very well with another car
    	and/or Radio, indipendently of the $ paid for one of these) and
    	connect the CD player directly to radio/amp.
    
    
    I hope it helps, 
    	     Toni.
236.2Supressers?RUTILE::BISHOPTue Dec 11 1990 14:276
    Are you sure its not the supresers ? (sp?)
    
    Does the sound go up and down with the engine tone?
    
    
    				Lewis.
236.3that happened to me !HAMPS::IVES_JI've got a bad feeling, Mr Tracey!Wed Dec 12 1990 19:4320
    Ahhhhh
    
    Have you tried the cassette both ways around ??????
    
    I had exactly the same problem but found that by "dressing" the cable
    such that I put the cassette in the other way around (confused ? what I
    mean is imagine the cassette you are playing ends and you turn it over
    - like that). Mine is a sony and the plastin insert in the top can be
    removed, the cable trailed the other way, then the whole thing inserted
    again. 
    
    Also try the line and or headphone socket, which ever you are'nt
    currently using. I think line gives better results, but you may find
    that using the headphone socket you can maximise the CD player volume,
    whilst minimising the cassette deck volume, thus hopefully reducing the
    noticable hum level. Watch it though as the CD player will CLIP if you
    go too loud.
    
    My main problem is where to place the player that minimises the jumping