Douk A5 Budget Stereo Amplifier Review

[W46n3r]

Amir needs to retest version 3 of this amp. Maybe there is even a v4 at the time I am writing this.

I bought mine 2 weeks ago and received a V2, dated 2025/01/08.

 

[ThsM]

Based on the review I just got one of these to drive a secondary bookshelf system that I put together as a DIY project. Running mostly Roon and Qobuz as my musical source through a Raspberry Pi 4 with a Hifiberry DAC2 Pro HAT. I can't believe how compact a system this is. It is replacing a Loxjie A30 mini-amp/dac.

Why did you replace the Loxjie? Is the A5 that much of an improvement over the A30?

 

[W46n3r]

I launched and installed the new Discrete Style opamp AK05 on Akliam and it looks great with the A5.

I was thinking of doing it myself. Are you using it with the 48V 5A power brick?

The seller says the operational voltage is ±9V ~ ±22V so I thought 48V would be pretty out of spec... or it doesn't really matter?

 

[WerewolfC]

I was thinking of doing it myself. Are you using it with the 48V 5A power brick?

The seller says the operational voltage is ±9V ~ ±22V so I thought 48V would be pretty out of spec... or it doesn't really matter?

According to A5 specs, the device's input voltage is DC 24-48V. As for the OP-AMP working voltage.... it should be lower. More powerful powerbrick means more output power on the speakers.


PS: just ordered mine on AliExpress for 64$ (32V power supply)

 

[ctakim]

Why did you replace the Loxjie? Is the A5 that much of an improvement over the A30?

Not that I can discern subjectively with my six decade old ears, but I do like the tiny form factor, simple, minimalist design with a satisfactory "click" to the dial to power on and off. And the low cost made this a super easy impulse buy. I may also give this to my daughter who lives in a very space constrained apartment. Such great sound coming out of such small boxes is pretty amazing!

 

[noise]

Any thoughts on the A5 Pro vs this one? I feel like the variable high pass filter is a really important feature. Or do the tone controls somehow overlap with the filter functionality?

 

[Bangtao]

Any thoughts on the A5 Pro vs this one? I feel like the variable high pass filter is a really important feature. Or do the tone controls somehow overlap with the filter functionality?

I am also thinking of the A5 pro but I am more interested with the headphone jack in front of the device.

I assume they have the same audio qualities. Is it correct ?

 

[Punchy_Power_Cat]

I feel like the variable high pass filter is a really important feature.

For someone who wants perfect sub integration, probably no. But obviously this is not the type of equipment high rollers look into.

• For someone who has a pair of low to upper medium class bookshelf/tower speakers that reach deep but lack quality (typical boomy sound) -> Go for it! It will clear them up, free the speakers from resonance they can't handle well and you can plug a sub to it. You will get even more sonic improvement out of this than you would get out of vastly better amp in terms of SINAD.
• For someone who has a pair of upper medium to high end bookshelf/tower speakers and does not enjoy or cannot play deep base -> Go for it! "same logic"

In any case. You shouldn't use the official power suppy unit. Buy a decent one from Meanwell, get the GST360A 48V/360W/450W peak or the 36V of the same model. They have remarkable low noise/ripple. In the range of a small 5V adaptor.

 

[Blew]

For someone who wants perfect sub integration, probably no. But obviously this is not the type of equipment high rollers look into.

• For someone who has a pair of low to upper medium class bookshelf/tower speakers that reach deep but lack quality (typical boomy sound) -> Go for it! It will clear them up, free the speakers from resonance they can't handle well and you can plug a sub to it. You will get even more sonic improvement out of this than you would get out of vastly better amp in terms of SINAD.
• For someone who has a pair of upper medium to high end bookshelf/tower speakers and does not enjoy or cannot play deep base -> Go for it! "same logic"

For me it's the latter and, perhaps more importantly, the ability to place a subwoofer in a position that distributes bass frequencies around the room better while not compromising the stereo imaging of the mains.

In any case. You shouldn't use the official power suppy unit. Buy a decent one from Meanwell, get the GST360A 48V/360W/450W peak or the 36V of the same model. They have remarkable low noise/ripple. In the range of a small 5V adaptor.

How would an alternative power supply improve the sound? Has this been measured?

 

[noise]

For someone who wants perfect sub integration, probably no. But obviously this is not the type of equipment high rollers look into.

• For someone who has a pair of low to upper medium class bookshelf/tower speakers that reach deep but lack quality (typical boomy sound) -> Go for it! It will clear them up, free the speakers from resonance they can't handle well and you can plug a sub to it. You will get even more sonic improvement out of this than you would get out of vastly better amp in terms of SINAD.
• For someone who has a pair of upper medium to high end bookshelf/tower speakers and does not enjoy or cannot play deep base -> Go for it! "same logic"

In any case. You shouldn't use the official power suppy unit. Buy a decent one from Meanwell, get the GST360A 48V/360W/450W peak or the 36V of the same model. They have remarkable low noise/ripple. In the range of a small 5V adaptor.

The speakers have an impled subwoofer crossover freq of ~175 Hz based on the subwoofer that was designed for them. I'm not planning on playing them loud, they are for a small desktop setup, so I don't think another PSU would be necessary.

 

[Blew]

Has anyone managed to take any measurements of the high-pass filter knob at various clock positions yet? It's not labelled and there are conflicting pieces of information about it.

In the review, @amirm measures what looks to be about 35-40Hz at 12 o'clock here,

Yet, according to this post on diyaudio, Douk Audio USA customer service advise:
"80Hz: It is recommended to point the knob towards around 11 o'clock;
100Hz: It is recommended to point in the direction from 12 o'clock to 1 o'clock.
But this is not a fixed value, it is still recommended that you adjust it slowly according to the device."

I'm not sure what they mean by "not a fixed value". Does it vary from unit to unit? Or do they mean it's logarithmic?

Then the calculations for each of linear and logarithmic pentiometer scenarios don't align with either of these.
For linear:
If 7 o'clock is 30Hz, 5 o'clock is 200Hz, then each "hour" (7 o'clock to 5 o'clock = 10 hours) equates to 17Hz ((200-30)/10).
Thus:

Clock position	Frequency (Hz)	Step (n)
7	30	0
8	47	1
9	64	2
10	81	3
11	98	4
12	115	5
1	132	6
2	149	7
3	166	8
4	183	9
5	200	10

For logarithmic:
10^(LOG10(30) + f * ((LOG10(200)-LOG10(30))/10))
Thus:

Clock Position	Frequency (Hz)	Step (n)
7	30.00	0
8	36.27	1
9	43.84	2
10	53.00	3
11	64.07	4
12	77.46	5
1	93.64	6
2	113.20	7
3	136.85	8
4	165.44	9
5	200.00	10

Both appear to be inconsistent with what both Douk customer service are saying and what Amir measured!

 

[avl2]

...
In any case. You shouldn't use the official power suppy unit. Buy a decent one from Meanwell, get the GST360A 48V/360W/450W peak or the 36V of the same model. They have remarkable low noise/ripple. In the range of a small 5V adaptor.

same question as in #329 : why do you say that ?

just by general hype thinking ?

do you know the role of the power supply on measured values (with this amp) ?

did you ask Amir (or someone else) if he has measured such D class or this Douk A5 with different power supplies and you know the results ?

no offense, but would be good here = in "audiosciencereview" having recommendations, based on objective facts

 

[Audionaut]

Has anyone managed to take any measurements of the high-pass filter knob at various clock positions yet? It's not labelled and there are conflicting pieces of information about it.

 

[W46n3r]

View attachment 460494

Interesting. My V2 doesn't have any label... just the 30Hz and the 200Hz.

 

[W46n3r]

I launched and installed the new Discrete Style opamp AK05 on Akliam and it looks great with the A5. The personality is close to Burson Opamp and I like it. It also looks great with the A5.

I received mine today. I'm not yet sure if I like it. To me it sounded louder at the same volume knob level when compared to the native NE5532. I wonder if any of the original dynamic range is being lost.

 

[Blew]

View attachment 460494

View attachment 460495

View attachment 460496

Where did these pictures come from? Is this a new version?
My V2 dated 25 Feb 2025 doesn't have the label.
The slope seems strange. It's not linear or logarithmic, and doesn't correlate with anything else. Where would 80Hz be?

 

[Audionaut]

Where did these pictures come from?

From my Smartphone
The Douk A5 V3