Sounds good, amp it up3 min read . Updated: 15 Oct 2013, 07:44 PM IST
A non-audiophile's guide to understanding amplifiers
I had never heard of a Lepai amplifier (amp) until a small package arrived at the doorstep of my son’s new apartment in the US last month. He was looking forward to setting up an audio system. The bookshelf speakers were already in place; only the amp was awaited.
The device that came out of the package was slightly thicker than a hardcover book and weighed approximately as much. It didn’t look impressive; in fact it looked a bit unfinished. It had volume, bass and treble knobs, came with a 12-volt DC adaptor and a promise to deliver 20 watts per channel. When I asked him the price, he said, “just $25" (around ₹ 1,500). That, I thought, perhaps explains the look. What more do you expect for that kind of money?
In 5 minutes the amp was connected to the speakers. He plugged in his iPhone, played a track, looked at me and smiled, and I said to myself, “I’ll be damned. This is not bad at all." In fact, for that kind of money, the sound was nice and smooth.
The Lepai amp is not a new product; it’s been around for nearly a decade. At one point it had quite a fan following. Earlier this year, the company launched an upgraded version: “LP-2020A+ Lepai Tripath Class-T Hi-Fi Audio Mini Amplifier (upgraded 2013 new version)." That “Tripath" in the name is for Adya S. Tripathi who designed the “Class-T chip amp" several years ago, and has since moved on. There’s an earlier model on Amazon that’s even cheaper by $5.
So how can an amp that delivers decent sound be so ridiculously cheap?
Sound is all about subtleties and perception; how you hear it is subjective. What’s decent for me can be dismal for someone else. My friend Viren Bakhshi, an audiophile who makes sophisticated tube amps under the brand name Lyrita Audio, says: “This subjective element is very important in audio."
When audiophiles discuss amps, they talk about classification. Bakhshi explained that all amplifiers are classified into four or five specific categories depending on their technology. In a normal amp (Class-A and Class-AB), the sound wave is not disturbed, it’s just amplified. While these amps produce top-class sound, they are very inefficient in terms of the power they consume and the output they deliver. For every watt of power output, they waste a lot of energy as heat.
Then there are Class-D amps in which the sound wave is altered and then reconstituted as close to the original as possible. These amps, developed about 10 years ago, are more efficient and also lighter (the components are miniaturized). They waste very little energy and, therefore, produce very little heat.
Tripathi took this a step further: He developed his own “chip amp" and patented it as Class-T. These are even more efficient than Class-D and require very little power (Lepai uses just 12 volts).
But “efficient" does not translate into better sound. The “inefficient" Class-A remains the first preferred choice of audiophiles because it gives superb sound, followed by Class-AB. There are high-end and relatively inexpensive amps in both Class-AB as well as Class-D. But Bakhshi feels that Class-D amps “haven’t lived up to the promise of sound quality...they don’t deliver richness of sound".
He didn’t say in as many words, but it’s fairly obvious that he doesn’t think much of Class-T. In fact, I’m quite certain that people who are serious about quality of sound will dismiss the Lepai as a toy.
It’s been about six or seven weeks since my son set up his amp. He says he is very happy with it: “It doesn’t pump up the bass or add any oomph to the music, so for rock it can feel a little underwhelming. But on quieter music it really shines."
That suits me fine. I have asked him to bring one for me when he comes home for Christmas. I am not an audiophile; so long as the treble is sharp and I can feel the bass, I am quite happy with the system.
Shekhar Bhatia is a former editor, Hindustan Times, a science buff and a geek at heart.