Features
Full range stereo.
Low pass or high pass internal crossover
Variable Bass Boost control
Jensen rates this amplifier at 180 watts x 2 or 360 watts bridged at 0.8% THD.
Test Report
Cosmetics
Jensen packaged the JPX720 amplifier in a relatively small chassis, considering its power output. The amp measures a mere 10" x 11" x 2.2". Exterior cosmetics are definitely unique, a love it or hate it design, if you will. The main portion of the amplifier is made up of an extruded aluminum heatsink anodized in a brilliant blue finish. Looking down upon the JPX720, large fins extend outward to the top and bottom. These fins are responsible for dissipating the majority of heat generated during operation. Atop the amp is a chrome wire mesh that flows over the majority of the real estate, and held in place with six, chrome-plated pan head machine screws. In the center of the amplifier, encompassed by plastic cladding, is the Jensen logo; this logo glows in a consistent cosmic blue when the amplifier is powered up. Just north of the logo are the power/protection L.E.D., and the level, crossover, and bass boost controls. Access to these controls requires the removal of a translucent blue acrylic plate mounted using a single, hand-tightened setscrew. To the sides, the charcoal gray injection molded plastic end plates are superbly finished and subtly incorporated into the JPX720's visual character.
Layout
Looking inside reveals a PCB layout that uses through-hole components and a single sided circuit board. Because of the board design, there are almost 50 printed circuit board jumpers. While this type of construction saves the consumer money, it can reduce reliability. Single sided boards lack plated-through holes, allowing components to sometimes vibrate loose.
The internal construction of the JPX720 is otherwise clean; the power and speaker connections are on one end, with audio on the opposite end. The gain and crossover controls are on the top of the unit, underneath the blue translucent cover, as mentioned. These controls are mounted to a small PCB, which is connected to the main board via a 10-pin jumper cable.
On the left side of the PCB you will find the power and speaker connections protruding through the chassis. These connections are standard gold-plated lug terminals enclosed by a plastic housing. The power terminals will accommodate #10 spade or bare stranded wire, sufficient for this power category. The manual specifies #8 gauge wire, but you may have a difficult time with this size wire. The speaker accepts a slightly smaller spade#12 wire.
For the audio connections, Jensen opted to use two sets of standard gold-plated style RCA receptacles; one set for input and another for output. These are located on the opposite side of the heatsink from the power terminals. High level inputs are also available as an input source when no low level (RCA) connections are available.
Power Supply
Jensen uses an unregulated power supply in the JPX720. This power supply employs six IRFZ46, 46 ampere MOSFETs. These are sufficient to supply the needed power. An input RF filter is included for the 12-volt power.
We give Jensen big thumbs up for the use of 105 C capacitors on the three 2,200uF filters used in the power supply section. As we have stressed many times before, capacitors can degrade over time in areas of extreme heat, so it is important to have high temperature capacitors in areas such as the power supply where temperatures may rise excessively.
Power Amp
The output of the amplifier uses four 2,200uF capacitors. Unfortunately, Jensen chose to use a lower grade 85 C caps in this section.
Powering the output are four 125 watt output devices per channel.