on August 14, 2013
SOUND & LONGEVITY
The sound and longevity of the Lepai is only as good as what you connect to it. The LP-2020A+ is not a $24 miracle worker. It is very cheaply made but still an incredible buy for the price. The Lepai does thin and muddy the sound of whatever you connect to it so it is advantageous to start with quality speakers that have a good frequency response. In the Amazon reviews for the main listing of the Lepai if you type in Bose, B&W, Definitive, Infinity, JBL, Carvin and Boston there are well over 100 reviews that come up. People that connect this amp to good speakers have more positive reviews of the amp. Taking it a step further, people that connect the Lepai to large bookshelf or floor standing speakers, perhaps unsurprisingly, achieve the best sound and have the least complaints. Looking at those reviews the Lepai is a 4 1/2 star product. I know sites like CNET suggest grabbing some old speakers in the garage gathering dust or a cheap pair of surround speakers or a an inexpensive pair of small bookshelf speakers with the Lepai to create a very affordable desktop setup. However, the reality is if you connect inexpensive speakers to this amp you will get mediocre sound
Looking at those reviews, people that connect this amp to quality speakers, large bookshelf or floorstanding speakers, along with having better sound have less failures with the amp. Less efficiency speakers can be more taxing on the amp and when listening to large full sounding speakers compared to small surround speakers you likely will not turn the volume up as high in order to fill the room with sound. If looking to connect the Lepai to a pair of 4 ohm speakers know that a 4 ohm load has less resistance, therefore the amp has to provide more current than with an 8 ohm load. This means that the output transistors have to be more robust with 4 ohm speakers than 8 ohm speakers. It's the cheap parts and circuitry, like the transistors, of the LP-2020A+ that are often failing and not Tripath's TA2020 chip because Topping uses the same chip but with better circuitry and other parts and doesn't have nearly the failures you see happening with the Lepai. Basically, you want the Lepai to do the least amount of work as possible. There are obviously some big quality control issues with the Lepai but it can't be coincidence that people connecting quality speakers to the amp have less failures and complaints.
VOLUME AND NOISE
The LP-2020A+ is rated at 20W per channel into 4 ohm speakers. 20W per channel is unachievable though. Taking into account the THD+N with 8 ohm speakers you can only achieve about 5-6W per channel of clean sound. It may not sound like much but it is enough to fill a room with music. When turning the power on and off my speakers pop. This is not surprising of an amp that is this inexpensive. I'm using the amp with Boston Acoustics HS60 speakers in an open 10' x 10' area. The speakers are on opposite sides of the area. The Boston's are 150 watt speakers, are 8 ohms, have a 6 1/2" woofer and 1" tweeter, and have a sensitivity of 89dB. With the volume turned up to 1 1/2 the amp provides adequate listening. With the volume turned to 3 1/2 the area is full of sound. At 5, the Lepai is surprisingly loud however distortion is clearly creeping in at the midway point. Beyond the midway point, the distortion just gets worse and worse.
With the volume turned to 4 and no sound coming through noise is audible with my ear next to the speaker. At 5, noise is audible a foot away from the speaker. At 6, I can hear noise from a couple feet away. At 7, noise is clear coming through the speaker from several feet away. The LP-2020A+ produces significantly more noise than my Pioneer AV receiver. I feel no problem turning the LP-2020A+ up to 4 (11 o'clock) but don't recommend turning it past that considering the noise and distortion produced past that point.
This amp clearly doesn't sound as good as the Denon it is replacing or the Pioneer AV Receiver running my home theater system. I wasn't expecting it to, I just wanted a much, much smaller footprint! That doesn't mean the Lepai sounds bad. Not at all, it sounds good when using large bookshelf speakers! Doing a comparison with my Pioneer running a pair of Boston speakers which are the floor standing equivalent of the ones in my computer setup and playing the same music at the same time over both amps, the sound from the Lepai does sound thinner, not as crisp, doesn't have the separation, and doesn't have the bass. A small amount of that can be explained by the difference in bookshelf and floor standing speakers even though they have identical tweeters and woofers.
Connecting a pair of Polk OWM3 surround speakers to the Lepai the sound unsurprisingly becomes noticeably thinner and more muted than when listening to the much larger Boston HS60's. As mentioned earlier, the Lepai does thin and muddy whatever you connect to it. Overall, the sound from the Lepai is good. Taking into account the price and size, it's downright impressive! Considering most people will use the Lepai in place of multimedia speakers or a portable speaker setup for a smartphone, the sound from the LP-2020A+ with the Bostons blows away the sound from sub $200 multimedia speakers or portable speaker setups I've heard.
SUMMARY & OTHER OPTIONS
I've read countless reviews from the original posting of the Lepai, was one of the early ones to purchase and post in the 2013 model product listing, and have continued to read reviews for the 2013 model as they've come in. While the LP-2020A+ has been a 5 star product for me there remains to be quality control issues as evident in the negative reviews. For that reason I feel the amp only deserves 4 stars. Even if you stack the deck in your favor by connecting quality 8 ohm speakers to the LP-2020A+ and keep the volume at manageable levels, there is no guarantee that it won't fail. Even with the quality control issues, the LP-2020A+ I feel is a gamble worth taking as it has an unbeatable bang for your buck.
If you don't feel like gambling, the more expensive Topping TP30 and FiiO A1 Mini are worth considering. Perhaps if you have inefficient speakers or 4 ohm speakers the Topping or FiiO are the way to go anyway because each amp, being a much better build, will better be able to handle the demand from those speakers. People that have used both the TP30 and LP-2020A+ say the sound quality is the same unless you use the USB connection on the TP30. In that case the sound is tighter and has better bass. At $90 the TP30 is significantly more. The $80 FiiO with 14W per channel into 4 ohm speakers isn't as powerful as the Topping or Lepai. The FiiO A1 Mini has overwhelmingly positive reviews stating audiophile quality sound. The lower watt output of the A1 Mini isn't a huge deal since you get nowhere near the stated 20W per channel with the Lepai. After running the Lepai I'm glad I purchased it over the others. The Lepai is plenty good for a desktop system and best of all is very affordable.
According to CNET, the Audioengine N22 and Nuforce Dia, which both retail for $200, sound the best of the bunch when looking at affordable desktop amps. I recently purchased a used Nuforce Dia. The Dia is vastly superior to the LP-2020A+ in every regard. Whether it is worth 8x the price is debatable and depends on the individual. If you are looking to use an amp regularly, have a sub to plug in to a desktop amp, are seeking something with multiple inputs, and consider sound quality and build quality to be a major consideration, than yes, it is worth it. The Dia does offer audiophile sound quality, the Lepai does not. Just be aware that the Dia only accepts digital audio inputs.
I thought that the sound quality and power output from the LP-2020A+ paired with the Bukang power supply that shipped with it was good but thought if I could improve sound, power output, and reduce noise by getting a higher amp power supply, why not! I therefore purchased a 6a 12v power supply through Amazon. Having both power supplies plugged and then switching then back and forth on the amp a few dozen times I can confidently say that there is zero difference in sound quality between the 6a supply and the Bukang supply that shipped with the Lepai. I played music from a few different genres while switching the power supplies and not once was there an increase in sound quality or power output from the 6a supply. Pausing the music and then turning the volume up all the way the 6a power supply had no less noise than the Bukang supply.
I don't doubt that the LP-2020A+ has shipped with some bad power supplies. At one time the Lepai shipped with what sounded like a very suspect power supply from Vonage. A part of me wonders if there is now a placebo effect going on. I wanted to believe that buying a higher amp power supply would boost sound quality, power output, and reduce noise. Who wouldn't want those things! When I first played music with this 6a supply I thought, "Wow that sounds good!" Then when I switched to the Bukang supply I thought, "Mmm, that actually sounds the same!" Going back and forth a few dozen times confirmed it. Another option is that with the 2013 model the LP-2020A+ is finally shipping with an adequate power supply. Either way I bet many people have unnecessarily purchased a new power supply for their LP-2020A+.