Douk A5 Budget Stereo Amplifier Review

[Blew]

THD in measurements.

Are there measurements available anywhere comparing V1, V2, and V3?

 

[Blew]

Maybe @Fosi Audio could clarify what is different between V2 and V3?

What does Fosi have to do with it?

 

[truth_soldier]

actually the change is just R35 was added to the left column and C112 was moved from the left column below C110 to the right of C110 so the right column was shifted a bit but everything else looks the same.
@Kaameelis do you have any understanding of this circuit and change?

View attachment 501761

Those two caps C50 and C52 on the left in this pic of the V3 according to AI are likely "1uF snubber caps"...

V3 Douk A5's [B]polymer snubber caps are 1µF 100V SMD aluminum electrolytics[/B] positioned between TPA3255 outputs and LC filter coils.

Circuit function: Absorb switching spikes from TPA3255's 500kHz PWM
Critically damp LC ringing (100kHz-1MHz). Low ESR (20mΩ) converts spike energy to heat.
High ripple current survives 48V/300W peaks.

Sound improvement: Lowers Class D "digital artifacts"
Improved Treble, Imaging, Dynamics, and lower noise floor.

keep in mind the AI might be completely wrong. Who knows?

 

[truth_soldier]

they didnt add R35, they just moved it from its original position close to the opamp U12 (picture below) all the way up there. See how the other parts around U12 are still there (C124, C120, C8 etc) but R35 is not there anymore. The value is different though.

good catch.

I sent a DM to @Douk Audio asking if they can give us any info about the changes of V2 to V3.

EDIT: oh look here someone repping Douk mentioned the changes in V3 but not in detail... https://www.audiosciencereview.com/...s-shape-it-together.57320/page-7#post-2392117

 

[truth_soldier]

good catch.

I sent a DM to @Douk Audio asking if they can give us any info about the changes of V2 to V3.

EDIT: oh look here someone repping Douk mentioned the changes in V3 but not in detail... https://www.audiosciencereview.com/...s-shape-it-together.57320/page-7#post-2392117

View attachment 501786

@Douk Audio

1. What are the "calibration issues" that V2 had?... and what is meant by precision here?
2. What "component matching" do you mean just ensuring left and right channel components are closely matched?
3. Does this change to these electrolytic caps improve the sound quality or does it ONLY improve reliability/longevity?

 

[truth_soldier]

THD in measurements.

see above. It helps explain.
Tbh, I think they don't like to broadcast a lot of details because there is a lot of copycat going on between companies selling these low cost products.

 

[Blew]

good catch.

I sent a DM to @Douk Audio asking if they can give us any info about the changes of V2 to V3.

EDIT: oh look here someone repping Douk mentioned the changes in V3 but not in detail... https://www.audiosciencereview.com/...s-shape-it-together.57320/page-7#post-2392117

View attachment 501786

These are changes for V1 to V2, not V2 to V3:

From V1 to V2, maybe the Ampapa D1 is the V3 version and it will be released soon. Stay tuned.

 

[truth_soldier]

These are changes for V1 to V2, not V2 to V3:

That doesn't make much sense to me. As seen on PCB printing V1 was made in Oct. 2024 and V2 was already being made in Jan-Feb 2025.
Why would they be announcing V2 changes in Sept.2025?
At least one V3 PCB had printed July 2025 which aligns with their post above in September.

Also their above post is mentioned the change to 4-gang pot for the HPF. There is a much bigger HPF pot in V3 seen in the pics above while the size of V1 and V2 pots are the same. Plus their comment about "adopts electrolytic capacitor" aligns with the V3 appearance of the C50 and C52 1uF caps next to the big coils that wasn't present in V2.

ie, the description of changes by @Douk Audio in September in general fits V3 not V2.
I think most likely they mis-spoke in the post saying "from V1 to V2"

 

[truth_soldier]

yeah, you can see The Douk A5 V3 circuit has many changes.
The below image of V2 (left side) and V3 (right side) has just the changes I saw at first glance, maybe there are more.
Note the size difference of the HPF dial pot and changes in the components near it.
The coupling caps after the opamps were changed as well as caps between the TPA3255 and the output filter coils.

The question is, is how does V3 sound now compared to V2?
It's kinda annoying to me because it invalidates subjective reviews that people did in the past of V1 and V2 if (big if) V3 sounds different.


View attachment 501703

I noticed that the Aiyima A07 MAX used (qty 4 - 1uF 50V) of the same type of caps put in the A5 V3 (qty 2 - 1uF 100V).
This must be a somewhat common design choice now.

 

[truth_soldier]

That doesn't make much sense to me. As seen on PCB printing V1 was made in Oct. 2024 and V2 was already being made in Jan-Feb 2025.
Why would they be announcing V2 changes in Sept.2025?
At least one V3 PCB had printed July 2025 which aligns with their post above in September.

Also their above post is mentioned the change to 4-gang pot for the HPF. There is a much bigger HPF pot in V3 seen in the pics above while the size of V1 and V2 pots are the same. Plus their comment about "adopts electrolytic capacitor" aligns with the V3 appearance of the C50 and C52 1uF caps next to the big coils that wasn't present in V2.

ie, the description of changes by @Douk Audio in September in general fits V3 not V2.
I think most likely they mis-spoke in the post saying "from V1 to V2"

@Douk Audio kindly replied to my DM and clarified...

1. My interpretation of V3 changes was correct.
2. There is a V4 now! (or coming soon) that has a 5 minute auto-standby feature.

 

[MCH]

@Douk Audio kindly replied to my DM and clarified...

1. My interpretation of V3 changes was correct.
2. There is a V4 now! (or coming soon) that has a 5 minute auto-standby feature.

View attachment 502103

Thanks for sharing. I would be cautious about the auto standby until it is shown to come with a well implemented auto on (which is difficult) OR it is defeatable.

 

[truth_soldier]

until it is shown to come with a well implemented auto on (which is difficult)

why is it difficult to implement?

 

[MCH]

why is it difficult to implement?

Well, if you have followed others' attempts discussed in the forum, some are too sensitive and pick up noise from other devices and turn on when they should not, others are too little sensitive and don't turn on when they should, or turn off in the middle of the movie, others are too slow and you miss the first 5 seconds of music... It is difficult to do it well and even more keep everyone happy.

 

[truth_soldier]

Well, if you have followed others' attempts discussed in the forum, some are too sensitive and pick up noise from other devices and turn on when they should not, others are too little sensitive and don't turn on when they should, or turn off in the middle of the movie, others are too slow and you miss the first 5 seconds of music... It is difficult to do it well and even more keep everyone happy.

ah OK thanks. I vaguely remember maybe reading something about this in the past with a product I don't remember which.
Another tricky part is not only implementing it sufficiently well, but keeping the cost down for the low retail price of the A5.

 

[Blew]

@Douk Audio kindly replied to my DM and clarified...

1. My interpretation of V3 changes was correct.
2. There is a V4 now! (or coming soon) that has a 5 minute auto-standby feature.

That's very interesting, thanks for your efforts in clarifying this.

The changes between V1/V2 and V3 mean that the filter labels on V3 (eg 60Hz at 12 o'clock) don't necessarily apply to V1/V2! That explains the difference between the measurements posted here and the V3 label, as the measurements done so far in this forum have been on V1 and V2. I'd be interested to see measurements of the HPF filter in V3 given the changes.

Also, should we provide our own cooling solutions to V1/V2 units to prevent the "possible cracking" of V1/V2 filter capacitor? Eg I find that simply leaving the glass lid a little open on my V2 unit results in it running noticeable cooler. Does anyone have a good solution to keeping the lid propped open while being secure in place? I'd rather not remove it entirely as it would invite dust and potentially curious fingers.

 

[Douk Audio]

Hello,

Thank you @truth_soldier for helping share my reply! I really hope it helps clear things up for everyone who had questions about the different versions of A5!

Just a quick note: the V4 is still waiting for production at the moment, and we expect it to be available for sale around early February.

Also, I noticed some friends brought up possible concerns about the standby feature. I’ve checked with our engineer, and he confirmed that the auto-standby on the A5 won’t cause those issues, so you can use it with confidence.

We’re really looking forward to more users trying out the V4 and sharing their feedback with us!

Wishing everyone a happy New Year and all the best ahead!

Regards,
Huan from Douk Audio

 

[JRowland]

@Blew Copper (and a .5mm thermal pad), I’m using a 48v 10a supply. I can go hours of just about max volume in my garage and my A5 V2 is just warm.

 

[MCH]

Hello,

Thank you @truth_soldier for helping share my reply! I really hope it helps clear things up for everyone who had questions about the different versions of A5!

Just a quick note: the V4 is still waiting for production at the moment, and we expect it to be available for sale around early February.

Also, I noticed some friends brought up possible concerns about the standby feature. I’ve checked with our engineer, and he confirmed that the auto-standby on the A5 won’t cause those issues, so you can use it with confidence.

We’re really looking forward to more users trying out the V4 and sharing their feedback with us!

Wishing everyone a happy New Year and all the best ahead!

Regards,
Huan from Douk Audio

@Douk Audio can you post frequency response graphs of the high pass filter of version 3? Thanks

 

[Schlippwhip68]

So, here is a thing. I have the A5 and may order the Pro at a later date. I think this little amp is great. The A5 actually drives my Q Acoustics 5020 a little better that the Audiolab 6000a. The 6000a has a little more punch, soundstage depth and width but not by a country mile at all and given the price difference between the two, Douk Audio have hit a budget sweet spot with this amp.

This modified A5 Pro was found this morning as I was prospecting for an amp. It looks viable but what do you think ASR?

 

[truth_soldier]

So, here is a thing. I have the A5 and may order the Pro at a later date. I think this little amp is great. The A5 actually drives my Q Acoustics 5020 a little better that the Audiolab 6000a. The 6000a has a little more punch, soundstage depth and width but not by a country mile at all and given the price difference between the two, Douk Audio have hit a budget sweet spot with this amp.

This modified A5 Pro was found this morning as I was prospecting for an amp. It looks viable but what do you think ASR?

yes the PP supply bypass cap mod could help the A5 V2/V3. cheap enough to try.
but you're asking about the A5 Pro? This thread is not about the Pro model