This is a review and detailed measurements of the Ampapa/Douk Audio D1 stereo class D amplifier. It was sent to me by the company and costs US $199.99.
The D1 implements one of the best graphic emulation of VU meters I have seen! The OLED display looks nicer in person than the above picture. We even have some ballistics in there with slow decay. There are other visualizations but this one looked so nice that I stuck with it. Input selection and such is performed through the clickable volume control.
Turning the volume control causes the current value to be displayed.
The high pass filter control on the left with off click put a smile on my face yet again. Now you can properly roll off the lows so a subwoofer can take over, or avoid pushing your speakers too hard in low frequencies.
I was even more surprised to see the 1/4 inch balanced connectors as well as trigger for automatic powering of the unit. Company was seriously listening to feedback from ASR members!
The included power supply opts for higher voltage than current so ups the capability in 8 ohm more than 4 ohm. In use, the power supply temperature did not even rise above room temp --- remarkable efficiency.
As you see, there is tone control buttons on the remote. I did not bother to test them.
As I was testing the unit, by accident I shorted out the positive terminal of the left channel to the chassis. I saw a spark and that channel shut down. Worried that I had damaged the unit, I power cycled the amp using front panel and it came back to life. So pretty robust protection circuit.
By the end of the testing, the amp was warm but nothing concerning. There is plexiglass on top that allows you to swap op-amps (don't!).
Ampapa D1 Amplifier Measurements
I was yet again pleasantly surprised by the high SINAD produced by the D1 in both RCA or Balanced inputs:
Ranking is up there, nearly getting into upper tier of performance:
Dynamic range is excellent as well, especially for this price and class category:
Channel separation likewise, turns in good numbers:
Company advertises PFFB implementation which means it should have little load dependency. Alas, we see more than that:
EDIT: 8 ohm label should say Ampapa D1 8 ohm, not SMSL.
Since you have tone controls, you may be able to crudely compensate a bit for treble rise/fall due to impedance of your speakers.
Typical of this architecture, there is some rise in distortion in upper treble as indicated in multitone and 19+20 KHz intermodulation distortion tests:
Power delivery was healthy for such a small and low cost amplifier:
As you see, distortion rises more in one channel than the other. No matter what I did to my cabling and connections, I could not dial that out. While it could still be a wiring issue, it looks like a minor problem with the amp itself. Since even at highest level, SINAD is near 90 dB, I would not be concerned about it.
Sweeps of frequency vs power and distortion shows what we expect:
20 Hz was too much though but I suspect none of you would be driving speakers capable of going this low with this amplifier. As I showed earlier, 40 Hz power is quite good at over 120 watts.
The "weaker" channel improved negligible amount after warm up:
There is a rather high spike on power on so depending on how sensitive your speakers are, you may hear that:
Conclusions
The D1 nails the functionality I look for that doesn't frequently exist in amps at multiples of its price points. The amp while compact, is quite attractive with that nice OLED display. I did not comment on packaging but it comes as if you bought an iPhone or something! No sign of cost cutting anywhere. Measured performance is very good to excellent. The one exception is the weak implementation of PFFB to reduce load dependency.
Pricing is ridiculously low for an amp that produces whopping 170 watts times two into 4 ohm with the bevy of features we see here.
I am happy to highly recommend the Ampapa D1 amplifier. Yes, normally the frequency response load dependency would get a grade lower. But with all the other features and design, I upped my rating. You can disagree in the poll!
------------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
The D1 implements one of the best graphic emulation of VU meters I have seen! The OLED display looks nicer in person than the above picture. We even have some ballistics in there with slow decay. There are other visualizations but this one looked so nice that I stuck with it. Input selection and such is performed through the clickable volume control.
Turning the volume control causes the current value to be displayed.
The high pass filter control on the left with off click put a smile on my face yet again. Now you can properly roll off the lows so a subwoofer can take over, or avoid pushing your speakers too hard in low frequencies.
I was even more surprised to see the 1/4 inch balanced connectors as well as trigger for automatic powering of the unit. Company was seriously listening to feedback from ASR members!
The included power supply opts for higher voltage than current so ups the capability in 8 ohm more than 4 ohm. In use, the power supply temperature did not even rise above room temp --- remarkable efficiency.
As you see, there is tone control buttons on the remote. I did not bother to test them.
As I was testing the unit, by accident I shorted out the positive terminal of the left channel to the chassis. I saw a spark and that channel shut down. Worried that I had damaged the unit, I power cycled the amp using front panel and it came back to life. So pretty robust protection circuit.
By the end of the testing, the amp was warm but nothing concerning. There is plexiglass on top that allows you to swap op-amps (don't!).
Ampapa D1 Amplifier Measurements
I was yet again pleasantly surprised by the high SINAD produced by the D1 in both RCA or Balanced inputs:
Ranking is up there, nearly getting into upper tier of performance:
Dynamic range is excellent as well, especially for this price and class category:
Channel separation likewise, turns in good numbers:
Company advertises PFFB implementation which means it should have little load dependency. Alas, we see more than that:
EDIT: 8 ohm label should say Ampapa D1 8 ohm, not SMSL.
Since you have tone controls, you may be able to crudely compensate a bit for treble rise/fall due to impedance of your speakers.
Typical of this architecture, there is some rise in distortion in upper treble as indicated in multitone and 19+20 KHz intermodulation distortion tests:
Power delivery was healthy for such a small and low cost amplifier:
As you see, distortion rises more in one channel than the other. No matter what I did to my cabling and connections, I could not dial that out. While it could still be a wiring issue, it looks like a minor problem with the amp itself. Since even at highest level, SINAD is near 90 dB, I would not be concerned about it.
Sweeps of frequency vs power and distortion shows what we expect:
20 Hz was too much though but I suspect none of you would be driving speakers capable of going this low with this amplifier. As I showed earlier, 40 Hz power is quite good at over 120 watts.
The "weaker" channel improved negligible amount after warm up:
There is a rather high spike on power on so depending on how sensitive your speakers are, you may hear that:
Conclusions
The D1 nails the functionality I look for that doesn't frequently exist in amps at multiples of its price points. The amp while compact, is quite attractive with that nice OLED display. I did not comment on packaging but it comes as if you bought an iPhone or something! No sign of cost cutting anywhere. Measured performance is very good to excellent. The one exception is the weak implementation of PFFB to reduce load dependency.
Pricing is ridiculously low for an amp that produces whopping 170 watts times two into 4 ohm with the bevy of features we see here.
I am happy to highly recommend the Ampapa D1 amplifier. Yes, normally the frequency response load dependency would get a grade lower. But with all the other features and design, I upped my rating. You can disagree in the poll!
------------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
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