Line level volume control

What is line level volume control? Is it controlling the volume from line out port?

I have a dvd player.I have built a lm3886 based GC but the player cannot control the volume and GC has a fixed gain.So the music level is quite high.Can I connect a pot from line out of the dvd player to input of the GC to reduce this level. Is this good idea??
I want to keep it as simple as possible without a preamp.

Think of a pot as a voltage divider. One part of the
signal goes through a resistive value. Then it's
weakened by connecting it to ground.

What I'm proposing is to use a 5k fixed resistor
for the signal and a variable 100k resistor to shunt
to ground. The actual impedance your sources
see would vary between 5 k and whatever your
input impedance is.

In fact it may look like this :

In ----> 5k resistor ----> stepped attenuator -----> amplifier
??????????????????????????????????ground impedance resistor

or this ? :

In ----> 5k resistor -------------------------------------> amplifier
????????????stepped attenuator ground impedance resistor

You may try lower but may get in trouble with some sources.
I heard these low impedances may cause problems with
some tube output stages.

I think the noise level of a 5kOhm resistolr is much better
then a 50 or 100kOhm resistor. I feel that this is one
of the reasons why amps do not sound as good at low
volume. I'm using the Visky s102k ($15 a piece). If you
do not wnat to spend that much I would recommend
Holco H8.

I'm switching 15 resistors from signal to ground. I'm using
relays switched by a micro controller. This gives me
60 dB attenuation in 1 dB steps.

Then I've added Carlos's Opamp amplifier.

I've heard many pre-amps but this is one of the most detailed
ones possible. Switching from a Alps 100k pot to this
volume control made a hugh improvement.