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Product: Dayton Audio DTA-100a - integrated amplifier with Tripath TK2050 Class D chipset
Manufacturer: Dayton Audio - USA
Approx. price: 100$/75 €
Reviewer: Lucio Cadeddu - direttore@tnt-audio.com - TNT Italy
Reviewed: February 2011

Foreword

It's exciting to see how many new Class-D inexpensive integrated amps are hitting the market. Six years ago there was just the T-Amp: low power, no power supply, no real-world connections, cheap looks. Now, for nearly the same amount of money, we can get a lot more (see, for example, the Scythe SDA-1100). We also have other amps, with multiple inputs or higher power, albeit at higher prices. A small-sized, nicely crafted, real-world powered amplifier was missing. Up to now. Introducing you the Dayton Audio DTA-100a integrated amplifier: for just 100$ you get 30 real watts RMS of output power, a single (doubled: one in front, one in the rear) line-level input, a solid 24 volts external power supply, a headphone output and real-world connectors (gold-plated RCA's and bananas for speakers). All of this is installed into a very solid, nicely crafted black metal case, something that can be placed close to any serious HiFi component without causing visual harassment (let's admit the T-Amp was aestethically embarrassing :-)

Two words about Dayton Audio: the Company is located in Springboro, OHIO, a small city which was ranked the 41st best place to live in America by Money magazine (2009). Their catalog offers a very large variety of products, ranging from A/V components, electronics, speakers and even pro gear.

What's inside?

The DTA-100a uses Class-T Tripath technology inside, more precisely a TK2050 (TC2000 + TP2050) chipset. You can find the very same chipset on other DIY kit amplifier boards such as Sure, 41Hz and many others but, as far as I know, this is the first time this chip is used inside a finished, plug-and-play product costing less than 100$. And, of course, it is the same chipset used inside the Virtue Audio One and the Winsome Labs Mouse, both costing three times as much, at least. It should be remarked that these amps use very good and ultra-selected passive components and better PSU's, though.

If you wish to know more about the TK2050 chipset, please download the TK2050 datasheet. By TK2050 Tripath intended the combo TC2000 + TP2050, a Class D amplification system that is claimed to deliver 50 watts per channel. This isn't entirely correct (more on this later), at least as HiFi power figures are normally intended to be. The TK2050 performance is similar to the previous TK2051 but the TP2050 driver is a thermally enhanced PSOP package, which should allow for better heat removal. The Power Small Outline Package (PSOP for short) is a rectangular small outline IC package developed by Amkor that integrates a copper heat slug in its plastic body. The die is attached to this heat slug, increasing the chip's ability to dissipate heat and thus handle more power.

The TK2050 can be powered by a 30 Volts PSU but at Dayton Audio opted for a cheaper 24 volts/5 A/120 watt switching PSU, made by Ktec (HK). The umbilical cable that connects the PSU to the amp makes use of a ferrite cylinder, a protection against RFI/EMI, while it should be noted that the central pin is (+) positive, in case you wish to upgrade the PSU.

The DTA-100a offers a standard jack headphones output as well, powered via a cheap separate opamp, the HWD2108, 105mW per channel into 16 ohm load at less than 0.1% THD, see the datasheet for further details. The minijack in the front is NOT a second line input, it just gives you the option to connect a source frontally and that's all. The volume control acts as power-on switch as well. A very bright blue led glows when the amp is switched on. There's no stand-by mode and the PSU remains permanently on (a red led indicates it is connected to the mains).
The mainboard is rather crowded and the two Tripath chipsets are installed at the bottom of the PCB. In this way the TP2050 is permanently in contact, thanks to some thermal paste (see pic), with the metallic chassis that can act as heatsink. It should be remarked this is not the mainboard of the previous DTA-100 model. It has been revised at least 4 times since its first release (rev 1.4 is printed clearly on the mainboard). The PCB (and, I suspect, the whole amp) appears to be built in China by SHENZHEN G.T. ENTERPRISE LTD. The same amp can be found labelled as Incom GT-006 as well.

Availability

The Dayton DTA-100a can be purchased online directly at www.partsexpress.com (if the link doesn't work go to the Partsexpress.com website and search for the product) for 99.9$ or 89.5$ if you purchase more than 5 units at a time. A list of international distributors is also available at the Dayton Audio website.
In Europe, for example, the distributor is Intertechnik.de and sells the DTA-100a for 120 €. Some Dayton product can also be found on Amazon.com. For example, it seems the model APA-150 (see our review), a class AB amplifier with 50 watts per channel, for just 150$ (180 € at Intertechnik.de) can be found more easily. I'm pretty sure the DTA-100a will be available more easily, even on the Ebay platform.

TK2050, the power and the glory

I've tested the DTA-100a with two different speakers and against its natural competitors: Trends TA 10.1, Scythe SDA-1100 and an inexpensive hybrid amp which I'd like to keep top-secret at the moment :-)
Unfortunately I didn't have a Virtue Audio One amp within reach: using the very same chipset, it could have been an interesting match!
Everything was kept as stock: no special power cords, no damping feet, no upgraded PSUs etc. The listening notes you'll read below refer exactly to the amp you'll purchase. Let me remark once again that this is an improved version of the previous DTA-100 you might find reviewed elsewhere on forums: the mainboard is completely different and the volume pot, that seemed unbalanced on the previous release, now works flawlessly.

The DTA-100a is an amazing amplifier. It solves the problems of low powered Class D amplifiers in a snap: with real 30 watts per channel, it represents the answer for those who love the Tripath sound but need real World power output.
The tonal balance is slightly different from that of the TA2024 chipset some of you might have appreciated on the T-Amp (before) and on the Trends Audio TA 10.1/2 (after). It is slightly darker but it still possesses that transparency Tripath chips became famous for. Anyway, the first thing that catches the listener's attention is its bass range, irreverently powerful, fast and punchy. Forget the clean, precise yet lightweight bass of the TA2024: this TK 2050 is a woofer killer. I've tested it with some of my preferred killer bass tracks: Koyaanisqatsi (Philips Glass, orig. soundtrack), Teardrop (Massive Attack, Mezzanine) and The cost of freedom (Marlo Glen, This is Marlo Glen). Even when pushed hard this small amplifier has been able to take the woofers to their natural limits, almost effortlessly. And no, it is not the cheap boom-boom sound you'd expect from such a low-priced amp: you have power, fast response and extension. When compared to the other amps (Trends, Scythe and the hybrid one) the difference in terms of control, extension and responsiveness is outstanding and sometimes embarrassing.
Certainly the higher power output plays a key role but even with 91 dB speakers and at low listening levels, the difference is stunning. The lowest organ pedal notes in Koyaanisqatsi or the lower synthetic notes of the electronic bass in Teardrop have a weight and a depth that the other amps can't simply match. Summarizing, in terms of bass performance there's no game. The DTA-100a is a winner. Hands down.

Analyzing the mid and the high range it seems the DTA-100a does everything in a more solid way, perhaps it is not the most delicate of the amps but what you get is a realistic reproduction of voices, strings and percussions. One might desire that touch of extra finesse but this amp simply gets the job done, no quibbles.
The Trends Audio TA 10.1 might sound more delicate, less aggressive ...in a word, more audiophile sounding. Organ high notes, for example, appear more airy and, overall, smoother but when you compare male voices and male choirs you can't help but notice these possess less weight. The DTA-100a reproduces male choirs with a sense of drama the TA 10.1 fails to deliver. The hybrid amp sounds smoother as well but even a tad lighter. Perhaps this difference of weight can be less evident using small bookshelf loudspeaker but with full-range floorstanders it is not subtle. In few words, the sound produced by the DTA-100a seems bigger, perhaps not as refined as with the other low-powered competitors (traces of harshness here and there) but I've ended up preferring the real World performance of this Dayton amp.

Dynamics

The comparison here becomes unfair, considering the DTA-100a has almost 5 times the power of the Trends Audio and of the Scythe (the hybrid is a Class AB 20 watter). Even without pushing the small competitors to their limits, the difference in terms of micro and macro-dynamics is crystal clear: the sound is faster and the dynamic variations (voices, percussions, etc.) are handled with ease. This amplifier has enough muscles to drive even low-sensitivity speakers so you don't have to worry about that. I suspect it can even sound better, with increased drive, using a 30 volt PSU (I didn't have one handy, unfortunately).
PRaT scores very high in absolute terms and even a comparison with much better amplifiers doesn't put the small DTA-100a to shame. Don't be afraid to play every musical genre, this amp will not run out of steam easily: I've tried my best to embarrass it, with modest results. Be it trip-hop, metal, organ and choirs, whatever, it can handle everything with ease. Want a party? Choose the right speakers and turn up the volume!

3D soundstage

The sensation of big sound is confirmed by the analysis of the soundstaging capabilities of this amplifier: the virtual image is large, way larger than the one created by the TA 10.1, the Scythe and the hybrid amp. Only the TA 10.1 does better in terms of height of the image, everything else (width and depth) is worse.
The TA 10.1 does better even in terms of detail retrieval: singers and players appear more clearly separated one from the other while the DTA-100a seems to prefer to focus its attention on the big picture, forgetting tiny details here and there. Again, I don't think the typical customer of this amplifier will care a lot about 3D soundstage, which is mainly an audiophile/audiophool thing. In any case, the DTA-100a images well, much better than one might expect, confirming, once more, that Class D amps - even the cheapest ones - perform nicely in this department.

Some advice & tweak

The owner's manual recommends to avoid speakers with a <4 ohm load. This is exactly what the TK2050 datasheet recommends. The only problem, actually, is heat build-up when driving low loads at high listening levels. I've used this amp with 4 ohm speakers without experimenting any trouble or fault. Your mileage may vary depending on speakers (impedance is never constant and varies with frequency as well).
If you wish, you can try a beefier 30 Volts PSU, just to extract every ounce of power from the Tripath chipset :-) I'm afraid this tweak will void the warranty, though.
You can even think to change the speakers binding posts, so to be able to use bare wire or forks. Be careful choosing the new posts since the space available between posts might be an annoying issue. Have a look at the rear panel of the amp to get an idea...
Headphones maniacs could plan to replace the cheap HWD2108 opamp with something of more audiophile heritage (sorry, no hints on this).

Complaints

Manufacturing & finish.
This small amp is nicely crafted, both inside and outside. The DTA-100a version solves some issues of questionable internal wiring and components installation on the PCB. There's still a large use of thermo-glue inside but, on the other hand, there's little room to keep everything together otherwise. One major complaint is the lack of multi-purpose speaker binding posts: you are forced to use bananas (supplied), no forks, no bare wire. Since the rear panel is actually very small there's little room for bulky connectors either.
The power-on blue led is definitely too bright. Some might like it, I've found it pretty annoying. The outboard PSU uses a figure-8 socket for the mains cable so installing a better cable might be more than a nuisance.
The internal Tripath chipset can be be powered with a +30V power supply, this way it can deliver 50 watts @ 8 ohm with < 3% THD. Realistically, the TK2050, with a 30V power supply, can deliver 30 watts at reasonably low (0.01%) THD figures on a 8 ohm load. Dayton Audio power supply delivers just 24 volts (24.1 on my tester), so the TK2050 produces 30 watt, at 0.05%, on a 6 ohm load. This means we're talking or real undistorted 20-25 watts of power on a standard 8 ohm load. Perhaps Dayton Audio can consider using a 30 volts PSU instead. The reason why a 24 volt PSU has been chosen is because this is easy to find, cheap, puts out 120W and is CE and U.L. approved. In any case, despite the undersized PSU, we still get 4-5 times the continuous power of a T-Amp/Trends TA 10.1/2 etc. Not a small difference.
The DTA-100a has just one line level input. Don't be fooled by the front jack input, it is NOT a second one: it is jut a duplicate of what's in the rear. I'd love to see the same amp with, at least, two, switchable real line-level inputs.
Sound.
When all's been said and done, it is difficult to write something against this small amplifier. Does it have traces of harshness in the mid-high range? Yes, a little bit. Is the height of its soundstage a bit constrained? Yes. Can the bass sound excessive with some full-sized speaker? Yes. At the end of it all, do you know another amp that can deliver such a good sound (and power!) at this low price? No.

Conclusions

If you love the Tripath Class-D sound but find the various 2024 (and similar) chipsets too underpowered for your needs, you should consider something with the TK2050 inside. It is THAT good, it has plenty of power, drive, right pace, powerful bass and the like. Purchasing a TK2050 finished amp was pretty expensive (300$ at least, expensive compared to the original T-Amp, of course). You could follow the DIY route, purchasing various TK2050 kits, adding a PSU, a cabinet, a volume pot etc. Now you can have everything for just 99$. It is not a bargain, it's a no-brainer steal. Loving your Trends TA.10.X or your Scythe SDA-1100 but feeling sad for their low power output? This is the amp for you, the real deal.

Copyright © 2011 Lucio Cadeddu - direttore@tnt-audio.com - www.tnt-audio.com

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