Precision Power A100.2 owner manual Differential Inputs, Fusing

The advanced protection circuit

was developed to prevent shut-	Watts
	100
off due to the fluctuating imped-
ance loads presented by today's
complex speaker systems. The
adaptive circuit optimizes output 50
power to maintain uninterrupted
operation whenever the amplifi-
er senses an impedance load of 25
less than 2 ohms. A low imped-
ance indicator (Diagnostic						Ohms
L.E.D. ) is provided to let you	8	4	2	1	0.5
		Figure A:	AM II Protection	Circuitry
know when the amplifier is oper-
			Output Power vs. Impedance

ating in this mode. It is important

to note that there is no increase in output power below the 2 Ohm threshold. Maximum power is achieved at 2 Ohms. AM III provides you the satisfaction of know- ing that your ArtSeries amplifier will continue to play when momentary impedance dips occur. (Refer to figure A)

In the case of a short circuit, AM III will engage to protect the shorted channel but will continue to play the unaffected channel. When this occurs, audible distortion will be heard. Turn off the system and repair this short. Once the problem has been repaired, the amplifier will return to normal operation.

Differential Inputs

One of the obstacles that must be overcome when designing a mobile audio system is that of external interference caused by alternators, generators, and other electrical subsystems. In other amplifiers, all input grounds are wired directly into the speaker ground, as shown in Figure B. The ArtSeries amplifiers, on the other hand, have iso- lation resistors between the input grounds and the speaker ground. This helps to pre- vent alternator noise from interfering with the signal between this unit and any prior "upstream" units.

Discrete Power Amp Circuitry

Exclusive use of discrete output transistors results in increased sonic transparency, outstanding dynamic range, and high instantaneous current capability. We've designed the power bandwidth to be from 10Hz to 50,000Hz +/- 1dB. This ability to produce full power with linear frequency response well beyond the threshold of human hearing insures that the amplifier's performance over the musical spectrum will be flawless.

The ArtSeries amplifiers are capable of operation into a two Ohm load in a stereo configuration and a four Ohm load in a bridge mono configuration. However, for optimum performance a four Ohm load in stereo and an eight Ohm load in mono are recommended. Refer to the Section on System Design for more information.

PPI's Exclusive Wire Connection System

Over the years, advances in mobile audio electronics have changed the demands placed on the type and size of wire needed to create a high-performance mobile audio system. To meet this need, PPI has created an exclusive wire connection system. This unique, removable connection system offers the versatility of terminal strips, the convenience of quick connect / disconnect style connectors, and the reliability afforded by direct connection to the circuit board. The power and ground connector will accept cable up to 6 gauge in size. The speaker/ remote tum-on connector will accept cables up to 10 gauge in size. Refer to the Section on Installation for more information.

Fusing

The Art Series amplifier is protected from current over-load situations by a blade fuse (Maxi - Fuse ). This type of fuse has a number of advantages. First it's available in higher values, and its single element design is more effective than using two fuses of lower value. Second, we could board mount it. This eliminates the use of ‘jumperwires’ (from the end-panel to the circuit board) which improves reliability. Finally, they are readily available from any auto-supply store and are easy to service. The A100 & A200 use a 20 Amp fuse, the A300 - a 30 Amp fuse, the A600 - a 50 Amp fuse and the A1200 - 2 - 60 Amp fuses.

For safety reasons, PPI recommends that the power cable be fused at the positive terminal of the battery. If this fuse (not-supplied) is not installed, and the power wire shorts to ground (between the battery and the amplifier), a fire can result. The fuse at the battery should be of the same value as the fuse supplied with the amplifier. Consult your Authorized PPI Dealer for an appropriate in-line fuse that meets the needs of your installation.

Installation

PRIOR TO INSTALLATION of your new ArtSeries Amplifier it is important to consider the following: In your profession, your abilities and expertise insure a job well done. This is also true of professional car audio installers. It is their chosen profession, and why they do best. PPI believes so strongly in it's responsibility to you, that we invest heavily in hands-on training of professional installers. Our comprehensive system design and installation seminar provides our authorized dealers with the latest tech- niques to deal with the complexities of car audio today. There is more than meets the eye to insure that a car stereo reaches it's fullest potential. The trained professional, through experience, can approach, recognize, and address all the needs of the mobile audio environment. PPI highly recommends that this amplifier and/or any other mobile audio equipment be installed by a trained professional.