Lepai LP-168HA 2.1 2x40W Mini Amplifier + 1x68W Sub Output

There are plenty of reviews detailing the features of this amp, so I'm going to discuss my specific setup, what worked for me, and what didn't.I purchased this amp to power the audio for my Burning Man bicycle, which is using a Tang Band W8-670C 8" 8ohm subwoofer in a ported enclosure, and two Tang Band W3-594SB 3" 8ohm drivers in sealed enclosures.MOSFET's, heat, and thermal pasteMy amp doesn't get very warm, even after an extended period of music at high volume. Several other reviewers reported poor factory application of thermal paste, so I was concerned that the heatsink wasn't getting warm due to the MOSFET's not making good contact. I opened it up to check and they looked just fine, but I went ahead and re-applied some thermal paste for good measure. After doing this I haven't noticed any difference in performance or temperature.CrossoverThe LPF crossover is a total joke. Mine "works" in that I can hear an audible change in the subwoofer output as I turn the knob, but the amp still sends the subwoofer nearly full-range input. Using only the included crossover, the overall audio quality is mediocre, and both the subwoofer and drivers were clipping well below the volume I had hoped for.I ended up purchasing a 225hz LPF crossover (http://www.amazon.com/gp/product/B00FNI3N4Y/), and it made a world of difference. The overall volume can now get much louder without clipping, the subwoofer hits harder, and the drivers sound great. With the crossover installed, this no longer sounds like a cheap ~$30 amplifier. If you are using this to power a subwoofer, do yourself a favor and get a crossover! You won't regret it!Power SourceThe included 12V 3A power supply works acceptably, but prevents the amp from reaching full volume. I've had the best luck with either a 12V 5A power supply, or a 12V SLA battery. Checking with an ammeter, the highest current I saw at full volume (with a bass-heavy track) was just over 4A @ 12V.RattlingI have this amp mounted on the subwoofer enclosure, and I quickly discovered that it likes to rattle. All of the knobs rattle, as does the case. The case rattling can be solved by putting some hot glue on the inside of the seams where the case pieces attach, but I'm still grappling with the rattling knobs. My "best" solution so far is a piece of electrical tape stretched across the tops of all of the knobs, but I'm sure there is a better way to do it.Audio Input LevelsOne unexpected problem is that a high input voltage is required for the amp to reach maximum volume. I first used a second generation iPod Shuffle. This worked in that sound came out of the speakers, but it just didn't get particularly loud. I then tried two modern Android phones (an LG G2 and an HTC One M8). The HTC produced the highest volume and clearest sound, but both it and the LG worked pretty well. You should try a variety of input sources if you're not happy with the volume.Final ThoughtsBuy this amp (and a crossover)! I wasn't expecting much from a sub $30 amp, but it's a surprisingly cool little device.

First off, Me I have 14 years experience working on military electronics, and 18 years personal experience working with, building, and repairing audio equipment...So we have a little 2.1 Amp, listed as a 2x40Watt and 1x68W... so ok I automatically assume that those are max peak numbers, normally peak is listed as 1.5 - 2 times the RMS output so I expect to get an inexpensive 2x20Watt 1x34w amp.... NOPE...THE SHORT:this is a Very poorly build and very misrepresented product...Real SPECS: 2 Channels @ 7 Watts RMS and 1 Channel @ 28 Watts RMS @ 10% THD2 Channels @ 2 Watts RMS and 1 Channel @ 12 Watts RMS @ 1% THDHonestly don't waste your money.THE LONG:Testing Setup:I tested using 3 different power supply's :#1 : The stock 12V 3A (36W) it comes with.#2 : A switchable 12,15,16,18,19,20V 4.5A (90W) universal laptop supply.#3 : A 15V 40A (600W) Meanwell Switching power supply.Two different loads:#1: 2x 4ohm 50W Boston acoustic 4" drivers, and a pair of HiVi F10's (10" 100W driver) in parallel for a 4ohm load#2: 4ohm 3600W dummy loads.test equipment:ATTEN ADS 1062 60Mhz oscilloscopeFluke FM27 Digital multimeterAudio tool App on a android based phone (signal gen and basic RTA) using a Dayton iMM calibrated Mic.So I unpack the amp and check its Power supply... no problems, 56mv RMS of ripple, max I could pull out of it was 3.2A @ 11.6V, so it meets its specs...I hook it up and connect the 4" speakers.then i connect the source to it and run a 1KHz test tone at 320mV RMS into the RCA Jacks:Max output was 5.6V RMS, or 7.8Watts per channel... and there is a LOT of distortion compared to the input signal, and an odd pulsing fuzz on the o-scope... Hmmmnext I test the sub output... using a 100Hz test tone this time, still 320mV input, at max I got 9.6V RMS or about 21.6Watt. Again there is a LOT of distortion and that pulsing Fuzz on the O-scope...next I use the 15V setting on the 90W laptop supply:32mV RMS ripple on the PSU, and it will put out 5.8A...The Amp still maxes out at about 8W for the 2 main channels but I get 10.6V RMS or about 28W from the sub output now...Still have the distortion and the fuzz on the O-scope...finally I switch to the 4ohm dummy loads and the 600W Meanwell power supply.15mV RMS ripple and WAY more amperage than this little amp could ever use...Still 8W per channel, and 28W for the sub...no change in distortion or that odd fuzz...so next I test the amp with no signal, that fuzz is still there independent of the volume controls, it looks somewhat like ringing noise discharging thru a capacitor...so I tear the amp down... the preamp and tone controls use a 4558D dual op amp, not Bad, but far from good.the main amplifiers are a TDA7266 and a TDA7256...the TDA7266 is a 7 W + 7 W dual bridge amplifier, you can look up its data sheet.... it's RATED at 7W @ 10% THD per channelor 2W @ 1% THD (100Hz to 15KHz)...The TDA7256 is a 30W Bridge Amplifier rated for 30W @ 10% THD or 12W @ 1% THD...next I look over the layout, and I notice that the entire power load is going thru a single 20AWG jumper wire... there is a set of holes for there to be a Pair of jumpers but only one was used... then I see on the Ground side it's the same way, only it's only 22AWG!there is No inductor on the main power line just a 2700uf 16V cap. and a 3A protection diode.And as others mentioned there was almost no heatsink compound on the main amplifier chips.AT this point I stopped testing, I had intended to test its output response curve, and see what was wrong with the "crossover" it includes. But really I have no use for a 7 watt amp... I have built Pre-amps that could put out that at less than 0.03% THD... let alone 10%...so really don't waste your money, for the cost of this amp you can go down to Walmart, K-mart, Biglots, or whatever and buy a 2.1 computer speaker set and strip the amp from it, and be better off...