How to connect Discman to amplifier?

Hey there!
I recently purchased a TEAC integrated stereo amplifier.
I plan to hook it up to my Sony Discman.
The question is: should I connect the Discman through it's "line out" or through the "headphone out"?

I noticed that if I connect it to the headphone out, then I can control the bass from the bass controls on the Discman itself - this coupled with the bass control on the amplifiers results in even more bass from the speakers.
is this safe?

Does it have anything to do with this switch on the amp labelled "Source Direct"?

Please help.
Muchos Gracias.

Many manufacturers of cables make adapter cords...mine is from Straightwire.
Just trust your ears!!
Using the headphone out may cause some overdrive which might be irritating.
Good luck!
Troll ... 3 posts from Bono ... 3 different names ....
This one goes up to eleven!
Not telling!
What's happening in here?