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."
"Class-T architecture
Single Supply Operation
"Audiophile" Quality Sound
0.03% THD+N @ 10W 4ohm
0.1% THD+N @12W 4ohm
0.18% IHF-IM @ 1W 4ohm
High Power
25W @ 4ohm, 10% THD+N, VDD=14.6V
22W @ 4ohm, 10% THD+N, VDD=13.5V
13W @ 8ohm, 10% THD+N, VDD=13.5V
High Efficiency
88% @ 12W 8ohm
81% @ 20W 4ohm
Dynamic Range = 99dB
Mute and Sleep inputs
Turn-on & turn-off pop suppression
Over-current protection
Over-temperature protection
Bridged outputs
32-pin SSIP package"
"APPLICATIONS
DVD Players
Mini/Micro Component Systems
Computer / PC Multimedia
Cable Set-Top Products
Televisions
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.