old TDA 2009 problem (no music)

[guitar89]

I have brought this IC long long ago, so just thought of making a simple amplifier.
I already built it based on the schematic (figure 1) gave from manufacturer. It is quiet compare to TDA7240 i built last time, also prone to radiation (radio wave), but the main problem is that it won't produce music (have some background hiss, interference, etc)

http://www.datasheetcatalog.org/data.../378193_DS.pdf

Because this is experimental, I use crocodile clip for temporary connection.
When it is alone (on board, point-to-point method), the noise is quite low.
When I connect the input (C1/C2) leg with crocodile clip, the noise produced is loud and annoying (can't withstand for few more sec) I guess that is because of interference.

So I connected an extra resistor across input (C1/C2) to ground (100k ohm). When i connect the cable to input again, the noise is reduced, but you still know it exist and louder than idle noise.

Thus I try to connect the input cable to PC soundcard output, No music is produced (weirdly), but when i crankup the volume, the momentary spike of music presented at the output as strongly distorted sound, no other sound produced. ( intermittent peak sound)

Any idea what could happen ?

[guitar89]

TDA2009 Distort.mp3 - DivShare
(connected with 100k resistor from pin1 to ground) Only test with one channel (both inhibit the same problem)

This recorded file shows that :
In the initial few seconds, the sound was idle/ambient, so ignore it.
I started to crankup the volume from the beginning, slowly from 2% to about 60%. Then the headache starts.
Loud bangs sound occur is the sound, then notice at about 27th second and onwards, the musical part is more obvious, just don't understand why is it distorted to this degree.