Dynavin alternator whine, help diagnosing

[blkxer]

Hey guys,

I just recently installed the Dynavin head unit (replaced stock nav and DSP amp).

Setup:
'03 X5 4.4i
Dynavin head unit
Alpine 5 channel amp
Passive crossovers

I currently have an alternator whine (high pitch whine with rpm rise; revving the engine or accelerating during normal driving).

I've tried everything I can think of and researched on the internet; I'm out of ideas =(

1. made sure all unused plugs taped up with electrical tape
2. toggled the "Brake" option in the Dynavin settings menu
3. grounded the "Park" wire on the Fakra cable
4. grounded the Fakra ground cable (black wire) directly to a metal piece in the vehicle (also tried grounding to the same bolt as the amp's ground wire)
5. adjusted the gain down on the aftermarket amp (helps make it less obvious, but still there)
6. pulled all the RCA cables (Streetwires twisted pair) from under the carpet floor and had it running straight through the interior cabin from the head unit to the amp
7. installed a ground loop isolator (also helps make it less obvious, but still there)
8. cut the amp ground cable to the bare minimum
9. used a dremel to sand down the contact point where I bolted the amp ground cable to a medal piece in the vehicle
10. installed a power line filter on the yellow wire of the Fakra cable closest to the plug into the head unit
11. cut all of the FL/FR/RL/RR audio cable line outs in the Fakra and taped them up individually (using RCA output only)
12. used the shorter harness to connect the head unit directly in the trunk and running a short regular RCA to the amp

I had the head unit and amp on and RCA wires disconnected = no alternator whine. Plugged the RCA cable to the amp, but disconnected from the head unit, amp and head unit turned on = no alternator whine. Plugged the RCA cable into the head unit and head unit and amp turned on = yes alternator whine.

At this point, I am pretty sure I can rule out the passive crossovers, Alpine amp, RCA wires, and Fakra cable. Unless there's anything else I can try, the only thing left is the Dynavin head unit (head unit itself, or all the RCA output plugs). Do you think it could be a problem with the Dynavin unit itself?