Precision Poweri640.5 640-Watt 5-Channel iON Series Class D Full-Range Digital Stereo Bridgeable Amplifier

GREAT amp. When got this I was taken back by the size of it, of lack of size to be more accurate. This thing is tiny, think loaf of bread but 1.5" tall. This little thing cranks out the power. I am running 4 6x8's and a 6 inch Bazooka tube and it is more power then I need. This is in a Ford Ranger so there is not much space so this amp could not have been more perfect. It is also really solid and weighs a lot for such a little amplifier. I had my expectation set and they were blown away. This is a great amp. No noise or anything just clean power. Awesome.

I have this hooked up to stock speakers now using stock wiring plus an aftermarket JBL GTO 12" subwoofer at 2-ohms. Source is a Clarion CZ702. Shortly I'll have Polk dB speakers installed in the car but I figure now is a good time as any to give a quick review of this amp. The specifications, especially the S/N ratio, aren't spectacular. Nevertheless, it sounds fine enough and it is indeed tiny. I don't have any noise or hiss and it reaches clipping with the 5V pre-amp signal from my HU at approximately 1/4" plus a teensy bit turn on the gain, which is expected. Due to space requirements, it has to have RCA dongles vs. direct RCA ports on the amp. This was kind of annoying to deal with and make look presentable (even though it will reside under a seat) but it actually saved my but because the location I chose wouldn't have allowed for RCAs directly plugged into the amplifier anyway. Just be prepared to hide and secure six RCA connections somewhere. It is putting out at least more power than my Clarion HU - the stock speakers are not having fun with this amp. I have tuned the amp using a SMD DD-1 so no clipped signals, it's just that the stock speakers get maxed out pretty easily - it's a little funny, actually. The sub channel, for some reason, came with the Bass Boost 100% turned on and the crossover at its lowest Hz setting... I forgot to check this and thought at first the sub channel sucked. But once I fixed that I was surprised. It's not the strongest sub channel on earth, let's be honest. Is it putting out an actual 350 watts? Pff.. I've heard louder at 350 watts but could just be the JBL sub. It does get loud, though. And it's nice it comes with a bass knob - although, like ever other bass knob except JL Audio's, it pretty much is just an on/off switch more or less. Figure I'll come back and report on how it fairs with aftermarket speakers.

Compact size and excellent quality.

OK, let's note the requirements. This install is a basic audio upgrade in a daily driver vehicle that gets loaded down with people and gear. Minimal room for extra audio equipment. So, compact and able to be connected to high level inputs.System: upgrade door speakers and dash pods for highs and mids, maintain the stock head unit (for functionality), single 10" sub, and single 5 channel PPI 640.5 amp under the passenger seat (I have realistic expectations for a single amp). Amp to be connected via high level inputs.Initial visual impression of PPI i640.5, positive. Very compact, appeared to have a quality build with some weight behind it.Before connecting any speakers, I set the input levels of the amp up with a multimeter and test disc.Initial audio impression, the head unit turned on with the vehicle not running. At volume level "1", aweful. Incredible amount of audible static (hiss), static was overcome when the HU was turned up (above listening level). With the vehicle running, alternator whine and other electronic noise was being passed through and amplified. Not acceptable when connected to high level inputs (as advertised).I immediately ordered (yet to receive) an Audio Control LOC for filtering and conversion to RCA level inputs. I will post an update.Update.I received the Audio Control unit (another $120), dialed it in, and spoke with Audio Control 2 times for any other tricks and tips.Set up of the Audio Control (AC) unit was straight forward. Running a test disc with HU at 80%, my voltage out of the AC unit was only 1.4v rms (this is pretty low). Certainly did not exceed the 6v max input of the PPI i640.5. Then connected the amp. Turned the amp gain all the way down as instructed by AC. First audio impression, all the noise was gone! Unfortuneately, the music was very quiet. I disconnected the speakers, re-ran the test disc, and measure my speaker voltages (way lower than my calculated values, to no surprise). When I adjusted up the gain to the ideal level, the static was back but all alternator and other electronic vehicle noise was still absent. Music level was now proper at the expense of static (hiss).Resolution, I set voltages at less than half of ideal voltage level. This yielded no audible hiss and a moderate (not really acceptable) level of amplification (less than half ~25w). The music does sound quite nice now but amplification level is lacking. I'm on the fence for returning the amp as it does not handle speaker level inputs (of low voltage) very well, as advertised.The amp should perform better for those with aftermarket HU's with high voltage outputs. But then again it does have a S/N of 70dB, so be cautious of the attractive size and price tag.

Excellent amp! Still getting the highs and lows tuned just right, but this thing puts out some power! Using to power two 6x9 jbl stage speakers, with a Rockford sub. My only complaint is the placement of the input RCA dongles blocking the tuning dials, and the placement of the power ports.. they are directly over one another and it's extremely difficult to connect and the wires must be clean of any burrs or lose wire frays to prevent arching. But I suppose this is expected of an amp of this size which is less than half of my 300watt pioneer amp.

HIGH LEVEL INPUTS, IF YOUR USING THEM MAKE SURE YOU WIRE ALL OF THE GROUNDS TOGETHER AND DON'T GROUND THEM TO ANYTHING ELSE. When I first wired the amp up I grounded the high level input to the radio ground and got engine noise. I then tried other grounding methods and still got engine noise, and a lot of frustration. Finally I found a review on another brand of this same amp saying to do the above and the engine noise went away. I was very happy and am now happy with the amp.

You get what you pay for. Right side output are reversed polarity. Too bad because size is great. Returning this amp.

This little guy packs one hell of a punch! I used PPI back in the 90's. They were always top end. For some reason they have really fallen off the radar but I must say they are just as amazing and for a fraction of the price now. By far best value on the market today. No distortion once dialed in. No road or engine noise just dead silence. Vocals sound amazing using Polk Audio DB series. And tons if f solid clean bass from the sub also Polk Audio DB series.

Lots of clean power for such a small amp. Tucked up under the dash of my 04 Jeep TJ. Hid nicely under the steering column. Definitely happy I bought this unit as it powers all 4 speakers and the 10" sub too.

Muy buena potencia, muy buena calidad de sonido y muy pequeño, ideal para instalarlo debajo del asiento. 1 2 3

Produits ok pour le prix

Excellent power, low draw, great fidelity. Mount it and forget it!