Alpine PDX1.600

All of the Alpine Power Density amplifiers are offered in the the same chassis and made to stack up on supplied extra feet. You get two Allen keys supplied with the amplifier to tighten and undo the speaker and power connections. The speaker connection is a new Alpine design and uses a removable plug system so you can disconnect the speakers easily when you want to and the pluggy thing is idiot-proofed against being plugged in the wrong way around by dint of concentric, rather than side-by-side conductors in the plug and the use of some sort of shaped hole system. If you can reach it, you can plug it in and you will always be correctly connected. The power terminals are a meaty 8Ga size and the angled Allen headed grub screw connectors are positive and easy to use. There are four RCA plugholes, two for input and two for full range passing-on of the signal for neatness of install or those with few line outs to use.
You remove another small Allen headed screw to access the adjustments and then presumably lock them away behind it afterwards again so no-one (including you) can mess idly with the settings you have to mean it and remove the screw. Underneath this metal panel is found the input gain adjuster and a switch to choose between two ranges of orders of magnitude of voltages of signal input and a lowpass filter frequency selector sweep control. There is also a subsonic filter switch you can leave at ‘off’ or select from either 30Hz or a very low 15Hz, which is creditable and proves the real power is in there for this to be relevant.
– Class D ‘Power Density’ design for more watts for footprint and volume occupied
– 1 x 600w RMS @ 4 Ohms
– 1 x 600w RMS @ 2 Ohms
– Actual test certificate with amp serial R70310422 tested 16/3/07 at 716w @ 14.4V
– Aluminium panel heatsink with stack system for amplifier stacks up to three deep
– RCA input and RCA full range pass through outputs
– Adjustment controls hidden under a metal plate with Allen headed retainer bolt
– 8Ga. Power Terminals with Allen headed grub screw bare wire socket connection
– High cable diameter speaker connection plug and socket system
– Square blue illuminated power-on indicator on top plus two other status indicators
– 4Ga. Power Terminals with Allen headed grub screw bare wire socket connection
– Subsonic Filter switch choice of Off, 15Hz or 30Hz
– Adjustable dual input sensitivity ranges: 0.1V to 1.0V and 1.0V to 8.0V
– Frequency response 20Hz (+/-1dB) to 200Hz (-3dB)
– Signal to Noise Ratio 110dBA
– Low Pass Filter 24dB per Octave variable from 50Hz to 200Hz
– Fuse Rating 20A x 4
– HxWxD(mm) 62 x 257 x 192mm
Review by Adam Rayner
All the Alpine Power Density amplifiers are real pocket rockets. They are designed to take up less space than regular amps and with each one you get a set of four feet studs that can be fitted to the amp’s corners so as to act as spacers (or hifi feet) as you stack up to three in a neat heap. I saw plenty of this actual amplifier in use at the recent show big gallery) except that instead of making them hide away, each was given pride of place on the build they were driving. I like the look of the product, although it isn’t like an old school Aluminium surfboard that bespake of it’s power by sheer size. No, this a new concept in compact wellie and this small box came with an individual test certificate (something I have never seen in a Japanese amplifier carton before) showing it well over 15% more than specification, which is nice. I love the neat look and the deep blue illumination panel on the top and either end of the control cover. This really is a dense small spud and feels nicely solid when you heft it out of the carton.
I used it to power up a small eight inch driver from Alpine’s Type E series and despite it being rated for 120w, it was a good match and left a nice slice of headroom for the louder bits. The subwoofer got a good score for sound quality and indeed, the signal to noise ratio of this class D amplifier is years better than this sort of product used to muster at 110dB and really does deliver clean power. As I ran a Bass CD (an old dB Drag test disc as it happens) the subwoofer was fed a signal that varied with power and pitch very well without any signs of it running out of muscle. It isn’t cheap and you are going to be paying some of the miniaturisation costs involved in making something this clever, so the PDX series is about quality and compactness rather than trying to be most bang for the buck. It sounds clean and will allow audiophile quality bass to shine through if your woofer is good enough.
The features are relatively clever but lack any adjustable phase control, which would be nice and that panel has so much space underneath, it’d be nice to see some sexy EQ creep into the options but that would put the price up further. This does prove that the concept is no gimmick and that should you say stack a 2.150 with a 4.100 and one of these 1.600s, you really will have enough channels to run a hectic 5.1ch. surround system with dts or whatever you want to drive the amps with. The only thing I disliked was the lack of a retainer on the back of the shiny screw that holds the panel in place over the controls. It’s so easy to lose in a car and just falls out once the panel is removed. A spare one of these screws in the bits bag would be thoughtful if not re-specifying the fixing itself.
Small and clever.
Overall 8.4
Sound Quality 9
Power Output 9
Features 8
Build Quality 10
Value For Money 7