Description

This article is from the Car Audio FAQ, by Ian D. Bjorhovde (ianbjor@mobileaudio.com) with numerous contributions by others.

3.21 What's that weird motor noise I get with my portable CD player? [JSC]

Many people report problems while playing CDs from a portable CD player
into their car audio systems. The problem, stated very simply, has to
do with the stepping of the motor requiring a varying amount of current
and non-isolated power and audio signal grounds. Using a liberal
application of capacitors and inductors, this voltage variance can be
restricted to a window of 8.990 to 9.005V for a 9V CD player, yet even
the swing between these two levels is enough to cause annoyingly loud
noise on the outputs. It has been reported that this entire problem
can be solved by using a true DC-DC inverter at the power input to the
CD player.

Continue to:

• prev: 3.20 Can I use my portable CD player in my car? Won't it skip a lot? [JSC]
• Index
• next: 3.22 What are some good (and bad) brands of portable CD players?