Hi audio peeps! I need advice. I just received my 900W PA D5000.5 amp from Amazon and installed it yesterday. Before the installation of the PA D 5-channel amp, I had our temp amp (an old 300W Fenton 4-channel to power my MM6501 seps (front) and DB651 coaxials (rear) - no sub yet. With the temp amp, I had no noise besides the high-pitched powering off sound when amp is turned off

But with the PA D5000.5 amp, I'm getting some hiss/whine even if:

1) Radio is OFF (same scenario if my volume is set to 0 or fader/balance set to extremes)
2) RCA inputs are NOT plugged to the amp
3) Engine is OFF (I get engine whine in addition when engine is on).

Here's the thing: when I turn on the radio and adjust the radio volume/fader/balance so a speaker plays a sound. The hiss from that particular speaker is gone even I turn the radio off (and on again) afterwards or just the particular speaker "off" using fader/balance controls. This is true even when I start the engine.

But any speaker that hasn't played a sound since initially switching the car from OFF to ACC will have the hiss/whine

The hiss doesn't increase with the volume.

NOTE: My remote on wire is connected to the car's ACC so the amp turns on immediately even when my radio is OFF. Unfortunately, my factory head unit doesn't have a remote out.

But then again, with the temp amp, this doesn't matter, I don't have this noise at all.

What to do?

We're thinking of the following possibilities:
  • Static
  • Amplifier Ground Cable placement (Gauge 4 na as it is) - With the Fenton it's OK but with the more powerful Polk hindi siguro?
  • Other Ground? - Kaso hiss is there even when the RCAs are unplugged
  • Defective Amp - Huwag naman siguro, I had this shipped from the US