on December 27, 2013
I have been using the Lepai amp for almost 2 years. There are good and bad things that I noticed. Below is my summary of the Lepai mini amp:
1) This amp is really inexpensive. If you cannot spend more than 20 bucks then you may want to take a close look at this amp.
2) The sound quality albeit at low volume is pretty decent. This amp uses the TA2020 chip set which does offer quite low distortion at low volume.
3) The amp has tone controls so you can fiddle with the sound to some degree.
1) You'll be hard pressed to drive a pair of low-sensitivity or 8-Ohm speakers to decent volume with this amp. With an 8 Ohm speaker, you get clean sound to around 5 Watts only. If you crank the amp up to 10 Watts you'll already hit 10% distortion. With 4 Ohm speakers you can get up to 10 Watts per speaker. In fact, the wattage rating of this amp (2 x 20 Watts rms) is truly false. The power supply that comes with this amp gives 2 Amps at 12 Volts. At a power efficiency of 90% you'll get 2 x 10 Watts rms at the most. However, if you have some fairly small speakers then you may be fine. Otherwise, spend a little more and buy another amp.
2) This amp DOES NOT connect to many newer TVs which often no longer have analog RCA outs. Instead you'll either need to get an SPDIF-to-RCA converter or an amplifier such as the Amphony 250 or similar model that has an optical input which is compatible with TVs. My TV luckily does have RCA outs but be sure to check if your TV does.
3) The enclosure of this amp is fairly bulky and not exactly high quality. I opened up the enclosure and found that most of the interior is empty. What a waste of space! Also, there are some gaps and areas where Lepai could have spent a little more attention to detail in terms of quality. The knobs are fairly basic too and tend to come loose.
4) The rear speaker connector easily snaps out of its socket and doesn't accept thicker speaker wire easily. So you'll have to stick to fairly thin speaker wire.
To summarize, if you really cannot afford more than $20 on an amp then the Lepai is a decent choice. But don't expect the amp to drive larger speakers.
This is a clean sounding amplifier with only the controls one really needs. So its great for my parents who don't have the frame of mind to fiddle with too many controls. However, be aware of power supply issues.
1) I bought two of these at different times from Amazon. Both did not ship with power supply - even though they claimed to include them. Amazon has not corrected the product description even after I told them about it.
2) The shipped power supplies were to be a 2 amp one and a 6 amp one in the second case.
3) If you run this amplifier from a 2 amp power supply - here is some news for you. The theoretical max watts your system can deliver would be 12X2 = 24 watts - However, since the amp is running around 80% efficiency - you can get approx 24X0.8 = 18 watts max from this amplifier (best case scenario) or around 9 watts per channel. The problem comes as you drive the amplifier harder. The power supply voltages will start dipping, and as it does so, the amplifier will distort. So your clean sounding amplifier, won't sound so clean after all once you drive it past 7 - 8 watts.
4) To really use this amplifier with low distortion at high volumes, you should use a switching powersupply that delivers 12 to 13.5 volts at 4 amperes. 6 amps is a bit of an overkill, but recommended if you will be using 4 ohm speakers.
5) You cannot use this amplifer with an un-regulated transformer type powersupply rated at 12 volt. Their no-load voltage can be anywhere from 15 - 20 volt and can even be dangerous if connected to this amp - since the supply capacitor is rated at 16 volt.
6) Don't forget the log relationship between perceived loudness and watts - a 100 watt amplifier is only double the loudness of a 10 watt amplifier. So this amplifer does fine to fill up a room with sound using reasonably high efficiency speakers (I am using Bose 301's). Just don't expect to pump your subwoofer with it!
7) There are two LED's inside. Not sure why only one of them lights up (in both the amplifiers I purchased).
8) Its tone control implementation can do with a bit of improvement.
on January 19, 2013
This is a fine little amp for the price, but there are still quality control issues that need to be resolved; thus, buyers should be aware that getting a lemon now and then is a distinct possibility.
I have read some reviews stating that this unit was shipped without a power supply, and I've read of other QC problems. My unit is mislabeled on the back (or is wired backwards), so that the LEFT speaker channel is really the RIGHT, and vice versa. In addition, as you can see in one of my pictures, the power supply is mislabeled. Actually, the company misspelled its own name -- Asian Power DECICES Inc. instead of Asian Power DEVICES -- not a deal breaker, but a heads-up to buyers to be wary. I wonder what the Chinese expression for CAVEAT EMPTOR would be.
I bought this amp for its kitsch value, but I have to say that it is probably the best amp ever produced in this price range (small flaws aside). It pumps decent sound at reasonable volume, and the unit seldom even gets warm to the touch... certainly never hot.
Some have complained that this unit is so light that it slides around the tabletop or desktop when one tries to adjust the volume or tone... I'm not sure how that's a manufacturing issue, or how this can be considered a negative. Should the manufacturer add a steel plate to the bottom of this unit just to make it heavier so that it doesn't slide around? I merely attached four Velcro dots to the bottom and stuck it to my desk (see my pictures). Voila! Problem solved. Or, you can use the four slots in the amp's ample frame to screw it down if you're using this amp in a shop setting.
I'm running two 8-ohm two-way bookshelf speakers from this amp and I find that I get all the volume I need, with truly clean mids and highs. If you try to pump too much bass from this puppy, however, you will get distortion... better to add a powered sub if deep bass is your goal.
Overall, this little amp rocks and is an excellent value for money. If it hadn't been for the mislabeling issues, I would have given this unit five stars.
on August 11, 2012
UPDATED REVIEW 2/8/13:
Both of the original Lepai amps that I bought are working perfectly. I decided to buy another for the living room, but instead of buying it from Parts Express, my original seller, I decided to buy directly from Amazon. BIG MISTAKE ! It arrived a day late (ONTRAC shipping SUCKS !) it came in a different amp box that didn't even match the item and to make things worst it did not come with a power supply. Then when I plugged it in with another power supply, it didn't even work !! I returned it instead and now waiting to get my money back.
Ok let me just start out by saying that this little amp is powerful for its size weight and cost, but one suggestion...get a better power supply. This thing is LOUD!! Nothing wall shaking or anything of that sort, but for a patio or pool, it's more than enough.
Forget about the power supply / adapter it comes with, it's garbage! After turning it up too loud, the power supply can't take it, the blue light on the amp dims and the amp cuts off if turned up too loud. Now this isn't the amps fault, its the lack of power the supply pumps out. I bought a 12v 5amp power adapter for $9.99 that was meant for a computer monitor and it sounds so much louder and pumps out more watts. Now remember this amp does distort if turned up too loud, but that's expected with something that only cost twenty $20 dollars.
Problem solved, after the new power supply, no more cutting out, no more blue dimming light, everything is working perfectly!
on August 30, 2013
I can't help but be amazed at how small this amp is, how loud it can get, and how little it cost!. Bought this to mount in my car, because the stock head unit doesn't have an audio input, and it's functioning beautifully. It runs on 12v DC, so I was able to wire it directly to the car's ignition switched radio line. Set up a couple of 4PDT toggle switches to select between the stock head unit and this amp driving the speakers. Made a small hole in my dash and mounted the amp in there (the black case is held on by 3 philips screws and 4 torx screws, the size of which I no longer remember). The metal faceplate looks really nice in-dash. Got a cheap RCA cable, hooked it up to the amp, and passed it out through a small hole in the dash. Now I can be using my stock head unit, then hook up my cell phone and toggle a pair of switches to enjoy my own tunes.
Overall, with the front and rear speakers in serial totaling 8 ohms of impedance per channel, the sound quality is pretty good and it can get as loud as I want it to be. However, if I were to do it all over again, I think I'd get 2 of these amps instead of 1 and wire up one amp for the back speakers and the other for the front, thus giving each variable volume control.
This is a sweet little stereo amp based on T-amp chip technology. It is clean and powerful for its size. It comes with a wall wart power supply, but could also be battery powered if one desired. There are input connections in stereo RCA jacks and a 1/8 inch (3.5mm) stereo plug for mp3 players, CD players, video players, etc.
There is an actual power switch instead of a pot-based switch as on similar models previously offered by Sonic. There are also Bass and Treble controls, which can be quite handy in tailoring the sound a bit to the speakers and space.
I am using these for small PA applications and for desktop computer sound. I have plans to create a small guitar amp setup as well. I have used 6 of these in my "day job" and was so impressed I started buying them for home.
I have driven spot monitors like Carvin PM5-Bs and even JBL 10 inch 3-way studio monitors with these and similar amps, and they work very well, especially for small areas. One of these and a pair of Carvin monitors make for some pretty great desktop computer sound. (Until your cubicle neighbors complain, anyway.)
I haven't done any actual power measurements, but they are claimed to put out 20-25 watts per channel into 4 ohms, and my ears agree that those figures are probably accurate. I have only run them at 8 ohms, and have been pleased with the sound. I currently use one of these and JBL 10 inch 3-way studio monitors to provide computer sound for a 42 person classroom, and the sound is pretty amazing for a $20 dollar amp.
If you are looking for a small power amp that is light weight, takes up very little space, and sounds really good, look no further. Give these a try, I think you'll be impressed, too.
Oh, Parts Express is also great to do business with.
UPDATE: August 2011
In the interest of clarifying the power output capability of this amp (which has caused some contention - see comments), I am re-producing the stats for the TA2020-20 chip from Lepai's own spec sheet, which is freely available on the web.
"The TA2020-020 is a 20W (4ohm) continuous average per channel Class-T Digital Audio Power Amplifier IC
using Tripath's proprietary Digital Power Processing (DPPTM) technology. Class-T amplifiers offer both the
audio fidelity of Class-AB and the power efficiency of Class-D amplifiers."
Single Supply Operation
"Audiophile" Quality Sound
0.03% THD+N @ 10W 4ohm
0.1% THD+N @12W 4ohm
0.18% IHF-IM @ 1W 4ohm
25W @ 4ohm, 10% THD+N, VDD=14.6V
22W @ 4ohm, 10% THD+N, VDD=13.5V
13W @ 8ohm, 10% THD+N, VDD=13.5V
88% @ 12W 8ohm
81% @ 20W 4ohm
Dynamic Range = 99dB
Mute and Sleep inputs
Turn-on & turn-off pop suppression
32-pin SSIP package"
Mini/Micro Component Systems
Computer / PC Multimedia
Cable Set-Top Products
Battery Powered Systems"
The diagram with power to distortion curves is even more instructive, and I will try and add a jpeg of that so people can judge for themselves if Lepai is lying about the specs.
Are they fudging a bit calling this a 20 watt per channel amp? You could certainly make that case, given that they are quoting those specs at 4 ohms and 10 percent distortion, which is more distortion than most people would find acceptable in an audiophile application. Is Lepai pushing it a bit? Yes, but no more so than most consumer amp companies, or virtually ALL computer speaker makers, none of whom quote accurate specs for their systems.
I have been told by tech support for a well-known, widely sold PA amp manufacturer that they considerably over-spec their amps - their 120 watt amp can only be driven to 80 watts; if you go beyond that they WILL fail (which ours had done). Yet, they still sell the amp as a 120 watt amp and no one sues them. Lepai is not fudging anywhere near that badly, and they publish the actual specs for all to see. Carvin is the only company I have found to be truly honest about amp specs (although there may be others). Lepai at least gives one the specs so one can see how much they are fudging.
Are there applications where 10 percent distortion IS acceptable? Certainly. Some small PA and background ambient systems would be fine with that level. Obviously, listening to pristine recordings of orchestral music would NOT. A great deal depends on program material, speaker quality, and application. For most applications, 10 percent is not acceptable.
Again, I run these amps at 8 ohms through efficient speakers (Carvin PM-5B and JBL studio monitors), and find them to be very good performers FOR THE PRICE. I would not recommend running them into 4 ohms, unless you intend to keep the power level down.
At 8 ohms, per their device curves, you can hit 10 watts per channel and stay near or under 1 percent distortion - which is the definition of "High Fidelity" by international standards, and beyond which the normal human ear cannot discern any further lowering of distortion, according to some. At 4 ohms, you can get close to 18 watts per channel and still remain under 1 percent. Is it fudging to call an amp that produces 18 watts per channel at 1 percent distortion a "20 watt amp?" Not by much, and certainly not by the usual standards of most manufacturers. NOTE that with the stock power supply, 12 volts at 2 amps, you could not possibly get more than 12 watts per channel, if it were a perfect world (which it is not). A beefier supply would be required to get closer to those rated specs for the chip in this amp. Personally, I would call this a 10 watt amp, not 20. More and more vendors are adding the channel outputs together, rather than giving the per channel output, which has been standard practice in the stereo world.
Even so, I find these to be very useful little amps, and will continue to buy and use them as long as they are available. If you cannot afford the rather modest price to find out, then don't risk your money. If you want a good performing amp for the price of a few lattes, then go for it. I think you will be happy with these. If you are looking for an amp for your Home Entertainment system, I think you will want something with a lot more power. These are small amps for small jobs.
Also, if you have a power supply failure, which I did have with one of these amps, Parts Express has very good replacements for a very good price. Parts Express is a very good vendor, and I have bought from them for many years. I bought all 7 of the amps I have used from Parts Express.
Still highly recommended.