This is a review and detailed measurements of the DTA-120 "class T" stereo audio amplifier. I purchased it at prompting of the membership months back. The DTA-120 for US $78. Parts Express now shows this as discontinued so not sure what availability is now.
The DTA-120 has a heftier build that other little amplifiers:
The volume control feels good. I did not play with either headphone output.
The back shows what you would expect:
Nice to see full regulatory certification in the form of FCC and CE marks.
The external power supply that feeds it is massive and probably even longer than the amp itself! It is rated at 24 volt/5 amps.
In use the unit barely got warm. This is actually good news which tells me it possibly uses the case for heatsink rather than looks.
The banana jacks, despite being tiny, managed to handle my heavy cable. And its oversized feet kept it rather planted.
Overall, decent impression for a budget product.
Amplifier Audio Measurements
As usual let's start with our dashboard view of 1 kHz tone at 5 watts into 4 ohm load:
The channel imbalance is bit more than I like to see. Shame we don't have balance controls anymore in our audio gear to compensate for such things.
THD+N and hence SINAD (signal relative to sum of distortion and noise) is dominated by strong harmonics, putting the DTA-120 near the bottom of the pile:
Frequency response has dual personality. Here it is at 8 ohm:
A bit of peaking/exaggeration of high frequencies is seen which is due to filtering used in switching amplifiers. At 4 ohm though, response radically changes:
Clearly the output filter is interacting with the load causing frequency response to vary. So what you get with your speaker of choice, will vary yet again.
That early and strong filter has some benefit in suppressing ultrasonic switching noise:
Multitone shows what we can already tell from the SINAD:
Most important test is the amount of power relative to distortion and noise. Let's see that for 8 ohm load:
Not a fan of those wiggly curves. And that fact that they start horizontally meaning distortion (rather than noise) dominates.
Situation does not improve with 4 ohm load:
Measuring power at 4 ohm again, this time opting for 1% THD we get:
So high frequencies are definitely more problematic.
We can skin that cat yet again by sweeping level at different frequencies:
Kind of messy as one would expect (ideal would be all the graphs on top of each other).
Here is the signal to noise ratio:
At full output, we barely clear the 16 bit hurdle.
Listening Tests
Watching important US news in another window so can't do the listening tests now. Will report later.
Conclusions
Measured by any kind of high fidelity standard, the Dayton Audio DTA-120 naturally is not competitive. There is way too much distortion. As a budget, low-cost amplifier goes though, it seems to work and product decent amount of power. So to the extent you want to use it in a workshop, workplace, etc., it would be fine.
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As always, questions, comments, corrections, etc. are welcome.
Having help clean up the yard because I got tired of waiting for @Thomas savage to do it. Need money to pay the guy when he is done today. So please help by donating using : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The DTA-120 has a heftier build that other little amplifiers:
The volume control feels good. I did not play with either headphone output.
The back shows what you would expect:
Nice to see full regulatory certification in the form of FCC and CE marks.
The external power supply that feeds it is massive and probably even longer than the amp itself! It is rated at 24 volt/5 amps.
In use the unit barely got warm. This is actually good news which tells me it possibly uses the case for heatsink rather than looks.
The banana jacks, despite being tiny, managed to handle my heavy cable. And its oversized feet kept it rather planted.
Overall, decent impression for a budget product.
Amplifier Audio Measurements
As usual let's start with our dashboard view of 1 kHz tone at 5 watts into 4 ohm load:
The channel imbalance is bit more than I like to see. Shame we don't have balance controls anymore in our audio gear to compensate for such things.
THD+N and hence SINAD (signal relative to sum of distortion and noise) is dominated by strong harmonics, putting the DTA-120 near the bottom of the pile:
Frequency response has dual personality. Here it is at 8 ohm:
A bit of peaking/exaggeration of high frequencies is seen which is due to filtering used in switching amplifiers. At 4 ohm though, response radically changes:
Clearly the output filter is interacting with the load causing frequency response to vary. So what you get with your speaker of choice, will vary yet again.
That early and strong filter has some benefit in suppressing ultrasonic switching noise:
Multitone shows what we can already tell from the SINAD:
Most important test is the amount of power relative to distortion and noise. Let's see that for 8 ohm load:
Not a fan of those wiggly curves. And that fact that they start horizontally meaning distortion (rather than noise) dominates.
Situation does not improve with 4 ohm load:
Measuring power at 4 ohm again, this time opting for 1% THD we get:
So high frequencies are definitely more problematic.
We can skin that cat yet again by sweeping level at different frequencies:
Kind of messy as one would expect (ideal would be all the graphs on top of each other).
Here is the signal to noise ratio:
At full output, we barely clear the 16 bit hurdle.
Listening Tests
Watching important US news in another window so can't do the listening tests now. Will report later.
Conclusions
Measured by any kind of high fidelity standard, the Dayton Audio DTA-120 naturally is not competitive. There is way too much distortion. As a budget, low-cost amplifier goes though, it seems to work and product decent amount of power. So to the extent you want to use it in a workshop, workplace, etc., it would be fine.
--------
As always, questions, comments, corrections, etc. are welcome.
Having help clean up the yard because I got tired of waiting for @Thomas savage to do it. Need money to pay the guy when he is done today. So please help by donating using : https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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