ads P850.2

Price Paid:  $300.00 from auction

Year / Model Reviewed:
 a/d/s p 850.2

Strengths:
pure clean power no need for multple RCAs one set does it all just a nice amp......

Weaknesses:
none

Summary:
more than what i expected 1 amp does it all even running a sub gona purchase a second one for the ultimate system

Similar Products Used:
sound stream mtx xtant altec lancing ppi ect.

Price Paid:  $700.00 from ebay

Year / Model Reviewed:
2004 a/d/s p850.2

Strengths:
Pure power, functionality, low profile design, beefy components

Weaknesses:
Voltage bleed issue, tuning amp can be difficult with the screwdriver controls

Summary:
I have to say that a/d/s is a phenominal electronics manufaturer. The 850 has lots of headroom and many onboard controls that save the space in your car that would be left to xovers. This is a wonderful amp to run an entire system with a sub.

Here are a few of the issues that I had with this amp before I gave up on it.

1. The set screw terminals for the power and other wire connections need to be checked constantly. I found that the power and ground connections would come loose and easily pull out of the amp after a week of driving from road vibrations.

2. Most importantly. After a month of conversations with the techs and one engineer at Directed Electronics (they own a/d/s and are the authorized servicer) I finally had to give the amp up. The problem I had was simple and apparently a function of the amps normal operation. In my 04 BMW M3 Cabrio with nav and the premium Harmon Kardon system the head unit would go into protection mode after about 20 minutes of operation. To make a long story short, there was 4.6 volts between ground and the jackets of the input RCA jacks even with the amp off. This voltage travelled through the cables connected to the LOC and then to the radio tripping the internal protection circuit.

a/d/s says this is normal and is common on the amp that they have at their shop. The options were; find the common ground on the circuit board for the jacks and insert a diode coupling, get a new head unit (retrofitting the nav system), or get rid of it. I chose the latter and decided to use a JL 500/5. If anyone experiences this problem within their systems this will most likely be the culprit.

Similar Products Used:
JL Audio 500/5