K2020A+ Class T

Update - the amp performance still bothered me, too many positive reviews here so I did more testing. I tried yet another set of speakers, some Paradigm Atoms that seemed to be sized well for the T2020. I also dragged out my AudioSource Model 2 so I could baseline the Atoms. Turns out the Atoms sound fine with the Kinter. So why didn't the Klipsch sound fine? I expect the two 6" woofers were just a bit much for the Kinter and the 12V factory supply and that's why the bass suffered. Also the tweeter in the Klipsch is way louder than the Atoms - I didn't not hear the switching noise as loudly with the Atoms but clearly heard it with the Klipsch. How does the T2020 compare with the AudioSource on the Atoms? It's probably 90% as good according to my tin ears. Bass was fine, treble was fine, nothing fuzzy or distorted sounding; totally acceptable for the price of the T2020. What about the switching noise? Well turns out I was probably hearing some inter-mods aliasing down in the audio range. With the volume all the way down and the audio input cable disconnected from the source you can see an 870KHz oscillation on the speaker outputs from the class D driver. I tried to get a scope shot of the aliased lower frequency noise but the best I could do was a 32KHz-ish scope shot. My hearing rolls off sharply above 13KHz but you can definitely hear idle "hiss" if your tweeters are any good. Is it a problem? Well I will leave that up to you to decide, as a studio monitor this is probably not your amp but to fill a room with sound, you will probably never hear the hiss. How well did it do with bass and high frequency? Well I did some scope shots to get you some data. These were taken in parallel with the speaker acting as a load and you can see the switching hash at high frequencies to be sure but you can't really perceive it. The 40Hz looks fine on the scope and the 20KHz looks a little hashy but hey - that's how class D works, not much you can do about it. I included some shots of the AudioSource so you can see the difference. The sine wave was from a function generator app on an iPhone for both amps. The AudioSource has the higher p-p voltages and the cleaner output obviously. What about the minimus 7s? Well they stink compared to the Paradigms of course but that's kinda apples and oranges. When I put the minimus 7s on the AudioSource they sounded similar to the Kinter so I began to suspect there was a speaker problem. The woofer surround looked fine when it was mounted in the speaker but when I removed the drivers I could see a crack at the base of the foam, which is why the bass suffered so badly in these units. So I put in some generic 4" woofers and the minimus 7s sound ok now on both the AudioSource and the Kinter. To be honest the Kinter sounded slightly better as you could boost the bass with the tone controls to match the tiny speakers. Bottom line - buy this amp if you have reasonable expectations and reasonable speakers, it sounds fine and it is worth the money. If you are pushing too big a driver you might be sad, but for a modest system the T2020 does just fine. Oh and this is not a paid review, I bought this thing. Also bought a DAMGOO bluetooth amp with the TPA3116D2 part in it. That amp sounds fine as well given the cost, same comment on the hiss, but no scope shots of it yet. ================= original review below =================== Wanted to like this amp based on the many reviews but they didn't deliver at all on sound quality. Initially I hooked it up to a pair of Minimus-7s figuring they should be well matched and used my iPod as the source. Started with the tone knobs both on mid range. The high end was super bright and clear but bass was muted. Fine, cut back on the treble knob and cranked up the bass and the amp delivered a fuzzy and muted thump for every bass drum kick. Ok - maybe the surrounds on these speakers are bad? Nope - the drivers had been replaced and the foam was all good. Ok maybe the crossover is bad, I'll try a different speaker. So I hooked up a known good Klipsch RC3 center channel speaker which has 6" woofers in it. Cranked the bass up again and it started to come through but still felt very thin. For something like a cello or standup bass notes you can probably get away with it, but for any music with a backbeat and some punch this amp falls flat on its face. Also there is a continuous 13KHz hiss coming out of the speakers, either with or without an audio source - regardless of volume level. Very noticeable, not acceptable. The final straw was when I plugged the iPod back into the Cambridge Soundworks model 88 radio I was trying to replace. Night and day difference, the model 88 has tons of bass punch compared to this amp, and my model 88 has had a long and hard life in the shop and has been rode hard and put away wet. It has a tiny 4" driver and it put our more bass than the alleged 20W into the RC3. If you own Klipsch speakers you know how loud they get and how efficient they are, it's kinda their "thing". If this amp can't drive a Klipsch, what the heck can it drive? Maybe I got a dud, or maybe all the hype was too good to be true, don't really care. Don't buy this amp unless you long for the sounds of a paper dash speaker with a whizzer cone in your clapped out Chevy II, and a photo flash unit charging up next to your head.

Summary: Great sounding little amp for the price. More detail: Is it audiophile quality? Hmmm. Compared to what? Certainly I have not heard anything in this low price range that is this good and I've heard more expensive sound much, much worse. But spend more, get more - SURE! Definition on the same set of speakers (I tried a set of Klipsh bookshelf speakers as they were handy...) isn't as good as expensive amps I own, but this wasn't an expensive amp so that's not fair. For the money, average user will probably be blown away by the great sound from this little guy. Audiophines less so, but will still probably admit it is a great sound for the money and dollar-for-results are pretty impressive. It is only rated at 20W per channel, so you can't expect to be driving crazy big speakers, but small-ish and relatively efficient bookshelf speakers should work fine in a small room. I don't think they are fibbing on 20W x2 ... it's not a monster, but it's not anemic at all either. fit and feel: power switch is fine, doesn't feel mushy or cheap. Adapter appears good quality. Connections fine though I'd rather have had banana plugs for speakers ... but spring-retention thingies are working okay. Bass and treble pots are smooth and do their thing. Tone-defeat button does it's thing too, nothing exciting here. Volume pot turns very smoothly and very easily, but feels stable, no wobbling around or such. Could use better marking on volume dial to see setting as it has only a small detente, BUT a dab of fingernail polish or mark from a sharpie marker will fix this. Case looks good, no defects, mars or blemishes in finish. I found the sound to be fairly neutral at baseline. Definition seemed very good. I felt it would be good for classical, jazz, pop, etc.. For metal, R&B ... maybe not. Tone pots adjusts it as expected, but I felt if you moved things more than a little touch up or down, the sound got too "monkeyed with" sounding, but that's what I usually think of such heavy adjustments. For little tweaks, such as to match speakers, small Bass/Treble adjustments are fine and don't degrade sound. Just don't think you can spin up the bass pot all the way and turn it into some sort of bass-blasting monster that still sounds good across the rest of the frequency range. I didn't find it overly loud, but its 40W total seemed to have plenty of power for small applications / smaller spaces and most important to me, it seemed to stay CLEAN as I cranked it up a bit. This would be a great amp for a small space where you want decent sound but don't want do spend a lot. Think dorm room, office, kid's room, home gym, workshop, maybe even driving outdoor speakers for the deck (but put the amp indoors and run wires out through walls/doors/etc - it doesn't look at all weatherproof). However, while it >can< be the heart of a budget system, you are probably going to drop at least $100, probably over $150, on speakers to reach it's potential. Sure, it will drive cheaper speakers and you can certainly do so for that just-mentioned budget system or to get started. Just realize then your speakers will be the weak link and NOT this amp, so don't blame it. Overall, for what it is (a small and inexpensive 20W x2 class T amp), it performs amazingly well and exceeds my expectations in the quality of sound it pumps out.

Excelente equipo de audio! Los componentes internos Texas Instruments son digitales producion un audio HI FI único para audiofilos!

The sound is pretty amazing. The interface is simple, easy to setup, and operate. The unit is very light, so it's best if it can be mounted somewhere, otherwise every time you try to push a button or rotate a dial, it moves. The markup was a bit steep though (reason for docking a star), still a great purchase.

I bought this amp to replace an older Lepai that had given up the ghost, since the current Lepai or Lepy models don't use a tripath anymore and as a clone of those amps it fits the mounting holes I already had on my desk. It made my speakers buzz and whine softly from the moment I plugged it in, even without a source connected. Unfortunately I procrastinated a few months before setting it up and was well past the return period so I had to live with it. Tonight I woke up to the kind of popping and crackling noises that sounded like a bonfire and panicked thinking my apartment was about to burn down. Turns out there was no fire, I had just forgotten to turn this piece of junk off before going to bed and it was feeding loud static through my speakers. Since I won't be falling back asleep any time soon after that adrenaline surge, I'm instead writing this to warn other buyers: spend your money on something else.

Was working fine and now no sound. Switch with another amp and sound works fine. Kinter has not responded to request for replacement? Buyer Beware!!!!