Ampapa D1 Stereo Amplifier Review

[delta76]

If time is not a factor, then what is measured is a peak (i.e. unsustainable) power. This amp is rated at 120W+120W into 4Ω (see the Parameters section). If you think it is capable of producing more, leave it on with both channels driven to 1% THD for 24 hours and then we will see if the PS or the amp goes into overload/thermal protection.

The argument is getting pointless now. Amir applies same test protocol for every amp he tests, which I believe follows CEA-490A standard.
You can see the chart that it goes a bit further but 136w is when 1% THD is reached.

 

[john61ct]

It seems to have a better PFFB filter right? But you also lose EQ, BT and remote

I prefer Power Amp to not have those latter features anyway, whereas IF better PFFB is better in my use case (unsure about that) that is a core performance factor.

The power output gap compared to 3e A7 even more likely to be relevant for me.

But I have to say the dancing VU meters are unreasonably attractive to me, lots of added value there

 

[CD2]

It would be beneficial!

Aha! Beyond room correction, listener correction!

 

[phoenixdogfan]

At long last, huh? A cool looking, performant $200 power amp. Perfect pairing for Asci F6b's, or even C6b's.

As always, great review Amir. As a fan of Vu meters, I know you enjoyed this one. I'm sure this amp will make a lot of cash strapped audiophiles very happy, as well it should.

 

[amirm]

And now, a question for Amir :
Why the peak power of a lot of class D amps measures lower than their continuous power ?

Most of the time, I get the same power due to power supply being regulated. In most class AB amps, the power supply is not regulated so sags under load. As such it produces more power for short period of time.

The instances of it showing less power is puzzling indeed. It is some kind of interaction between how the test runs as it hunts for 1% distortion and the amp and power supply. In other words, I can't explain it. I do run it a couple of times to make sure it is the right number and it is.

 

[JRowland]

It seems to have a better PFFB filter right? But you also lose EQ, BT and remote

You lose TRS too, least expensive with least features. I run towers off of mine in my garage so I don’t use the high pass filter either. Hard to beat $69 if you have a power supply, what an awesome time for electronics and speakers we are in.

 

[PristineSound]

But why is this frequency dependent amp recommended and not the G7?

Oh, I know making fun of someone's name is juvenile, but I don't care. . .am-papa

 

[JSmith]

But why is this frequency dependent amp recommended and not the G7?

Likely due to;

JSmith

 

[Mort]

But why is this frequency dependent amp recommended and not the G7?

Oh, I know making fun of someone's name is juvenile, but I don't care. . .am-papa

It's the final sentence.

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!

 

[Bleib]

You lose TRS too, least expensive with least features. I run towers off of mine in my garage so I don’t use the high pass filter either. Hard to beat $69 if you have a power supply, what an awesome time for electronics and speakers we are in.

I don't see the point of balanced if the performance is still poorer..

 

[StivVid]

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.
View attachment 512719
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.
View attachment 512720
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:
View attachment 512721
View attachment 512722

Ranking is up there, nearly getting into upper tier of performance:
View attachment 512723
View attachment 512724

Dynamic range is excellent as well, especially for this price and class category:
View attachment 512725

Channel separation likewise, turns in good numbers:
View attachment 512727
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.
View attachment 512728

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:
View attachment 512730
View attachment 512731

Power delivery was healthy for such a small and low cost amplifier:
View attachment 512733
View attachment 512734
View attachment 512735
View attachment 512736

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:
View attachment 512737

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:
View attachment 512738

There is a rather high spike on power on so depending on how sensitive your speakers are, you may hear that:
View attachment 512739

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/

Another nice review. Thanks for all the work you do to analyze and recommend (or not) both new and vintage audio products.

One new trend has been bothering me a little though, and that's the digital VU meters that are being implemented on so many pieces of new gear. I don't really understand their purpose. Is it just for show, or is there a practical reason for their inclusion? I really only find them useful when calibrating recording levels between source and recording components. Am I missing something?

 

[amirm]

But why is this frequency dependent amp recommended and not the G7?

They both have the same frequency dependence. The G7 adds to it with much more distortion in low frequencies and one channel producing much less power. And little about its VU meter compensated for these things.

 

[DWPress]

But it's so tiny! Are those VU meters the size of postage stamps? Certainly only useful (?) for desktops.

 

[amirm]

But it's so tiny! Are those VU meters the size of postage stamps? Certainly only useful (?) for desktops.

They are the size of typical low to mid-priced hi-fi of 1980s. Definitely good enough for desktop use.

 

[Tovarich007]

Most of the time, I get the same power due to power supply being regulated. In most class AB amps, the power supply is not regulated so sags under load. As such it produces more power for short period of time.

The instances of it showing less power is puzzling indeed. It is some kind of interaction between how the test runs as it hunts for 1% distortion and the amp and power supply. In other words, I can't explain it. I do run it a couple of times to make sure it is the right number and it is.

Thanks a lot Amir for your explanation.
Do you think another power test equipment could change the result a bit ?
Anyway, the difference is puzzling yes, but in any case such a little power shift isn't audible.
It's only for the Ampapa D1 that a more important (not so much pratically) shift down in power can be seen for short term peak. Maybe their power supply ?

 

[HelloHell]

Sometimes I wonder: let’s imagine companies send out “special” units for reviews who can guarantee that the rest of the production will be the same?
It would be good to test a unit that was simply taken off the shelf or bought online, just to verify the accuracy and honesty of the results.
This isn’t about this specific brand — it applies to all brands in this product category.

 

[JSmith]

It would be good to test a unit that was simply taken off the shelf or bought online

Amir tests what he is sent, by the public and companies.

Probably half the items tested here were sent in by members.

Feel free to dropship one to Amir for secondary testing.


JSmith

 

[delta76]

Sometimes I wonder: let’s imagine companies send out “special” units for reviews who can guarantee that the rest of the production will be the same?
It would be good to test a unit that was simply taken off the shelf or bought online, just to verify the accuracy and honesty of the results.
This isn’t about this specific brand — it applies to all brands in this product category.

Amir did address this concern a while back, and while I can't find his exact post, I believe that he said he gives the manufacturers the benefit of the doubts. If they cherry pick the products to be sent and his results do not align with other measurements then things will be falling apart quickly.

 

[HelloHell]

Amir tests what he is sent, by the public and companies.

Probably half the items tested here were sent in by members.

Feel free to dropship one to Amir for secondary testing.


JSmith

I know, thank you. I live in Portugal, and the shipping cost plus receiving fees would end up being almost double the price of the product itself. But considering the “symbolic” cost of these products, it was something worth trying in favor of the consumer.

 

[JSmith]

I know, thank you. I live in Portugal, and the shipping cost plus receiving fees would end up being almost double the price of the product itself.

Sure, I understand.

To be honest, the discussion about "golden samples" is bandied around often and usually with no evidence of impropriety. Most of the companies that send things to Amir for testing really don't have any reason to play such games and would be easily caught out by members of ASR and other forums that do their own testing and teardowns.

One manufacturer was accused of using fake opamps, then actually produced legit invoices here from a proper supplier. Some customers checked their own units and found nothing untoward. Many companies now include parts as part of their marketing... the very amp measured in this thread has a clear case top.


JSmith