Douk A5 Budget Stereo Amplifier Review

[enioentity]

Voted fine because it's a very well performing amp, with exceptional price-performance ratio. Highpass functionality is very nice and almost unique in this price range.

At the same time it's a good example of why I stay clear of these very cheap offerings. There's always a compromise or two. PFFB is nice but only ever a technical afterthought, and never perfect. External PSU is a hassle, and the device heating up in idle with a 48V one hints at inherent design problems.

Good for a super low budget. But in the meantime I'm gonna stick to the well tested formula of spending a few hundred instead, on a Hypex amp that is a long proven design and has none of these problems, while being cleaner and more powerful. Or any AB amp that measures well, from a reputable company for the same money.

If all you can spare is 100 moneys, this is perfectly fine. If you got a little more, look elsewhere.

what hyperx amp is few hundred?

 

[Birdy]

Voted fine because it's a very well performing amp, with exceptional price-performance ratio. Highpass functionality is very nice and almost unique in this price range.

At the same time it's a good example of why I stay clear of these very cheap offerings. There's always a compromise or two. PFFB is nice but only ever a technical afterthought, and never perfect. External PSU is a hassle, and the device heating up in idle with a 48V one hints at inherent design problems.

Good for a super low budget. But in the meantime I'm gonna stick to the well tested formula of spending a few hundred instead, on a Hypex amp that is a long proven design and has none of these problems, while being cleaner and more powerful. Or any AB amp that measures well, from a reputable company for the same money.

If all you can spare is 100 moneys, this is perfectly fine. If you got a little more, look elsewhere.

Why you would spend 4x more for the same sound quality? The compromise of a external psu is more about esthetics then sound and if you use a 36 / 40 volt PSU the problem with heating is resolved. If you have very hard to drive loudspeakers i can imagine you want more power. Many people love the "feel" and looks above functionality, but that has nothing to do with what comes to the ears.

 

[truth_soldier]

Even though I am using the 32v power supply, I made this "mod" for my Douk A5 to facilitate some passive airflow. Just used 2 sick on bumpers, but one could be used for each corner instead.

Love this. Such a simple solution, I'm embarrassed I didn't think of it.
my solution was this: https://www.audiosciencereview.com/...et-stereo-amplifier-review.61410/post-2500341

 

[truth_soldier]

Why you would spend 4x more for the same sound quality? The compromise of a external psu is more about esthetics then sound and if you use a 36 / 40 volt PSU the problem with heating is resolved. If you have very hard to drive loudspeakers i can imagine you want more power. Many people love the "feel" and looks above functionality, but that has nothing to do with what comes to the ears.

are you using the A5? I continue to be surprised how good it sounds completely stock, considering the price, as you improve the rest of the gear around it.
For example I have been modding my low cost tube amp and the system using this amp just keeps getting better sounding with each improvement to the preamp.
I also improved the power supply to my DAC.

 

[Birdy]

are you using the A5? I continue to be surprised how good it sounds completely stock, considering the price, as you improve the rest of the gear around it.
For example I have been modding my low cost tube amp and the system using this amp just keeps getting better sounding with each improvement to the preamp.
I also improved the power supply to my DAC.

Agree, it sounds great for me, after using even a DC coupled class A tube amp with separate PS and 35 watt in class A. This little amp is at least on par with that 14 kg heat monster. The details, bass and openness is just fantastic if you consider it's price point. I only exchanged the op amps for OPA2604AP that i already used in my Aiyima 07. No tube pre-amp anymore because it didn't sound as well with the extra distortion and some coloration. I don't feel any need for better then the Douk A5 with HP set to 40 Hz for mains and 07 for subwoofer.

 

[Ropeburn]

what hyperx amp is few hundred?

2x 125W nCore power amps are available from 400, and 500 for 2x250W.

 

[Bruce Morgen]

I have no earthly use for these things -- my old A07s are more than good enough for the job they're doing and they're DSP-corrected for their non-PFFB FR glitch -- but for $65 USD (sans power brick) with free shipping I may not to be able to resist buying one just for giggles and grins.

 

[truth_soldier]

No tube pre-amp anymore because it didn't sound as well with the extra distortion and some coloration
...
I only exchanged the op amps for OPA2604AP

which tube pre-amp did you try, one of the low cost chifi "hybrid" buffer types that use opamps or some kind of real non-hybrid tube preamp?
I have a suspicion that the op-amp hybrid types do as much harm as good when mated to the low cost TPA3255 amps - that they don't smooth out the slight hi-end haze/grainy-ness.

did you get the OPA2604AP chips on MercadoLivre, which vendor? (lots of fakes out there)

 

[Birdy]

which tube pre-amp did you try, one of the low cost chifi "hybrid" buffer types that use opamps or some kind of real non-hybrid tube preamp?
I have a suspicion that the op-amp hybrid types do as much harm as good when mated to the low cost TPA3255 amps - that they don't smooth out the slight hi-end haze/grainy-ness.

did you get the OPA2604AP chips on MercadoLivre, which vendor? (lots of fakes out there)

yes, i used a cheap chifi buffer amp with GE tubes and opa2134ap op amps. This was o.k. with the Aiyima 07 because of the load dependency and the tone controls but with the Douk A5 it was more of a fog over the sound so i removed it. The Douk A5 sounded far better then the 07 in many way's. I demoted my 07 as a sub amp which works fine. The op amps i bought on Ali express, seems to be original sound wise ;-)

 

[truth_soldier]

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.

Hi @Douk Audio any news on the V4 release?

 

[truth_soldier]

yes, i used a cheap chifi buffer amp with GE tubes and opa2134ap op amps. This was o.k. with the Aiyima 07 because of the load dependency and the tone controls but with the Douk A5 it was more of a fog over the sound so i removed it.

yeah well as I said I wonder if it's that particular type of "hybrid" design that uses opamps that's the problem, because I don't hear "fog" or loss of details, I hear more details with my slightly modified (also cheap) FX tube-02 Pro preamp I mentioned above.

 

[DavidR]

Now that I've used mine for a while I thought I'd provide my experience. I commented earlier when I substituted one for the amp running my dipole woofers in my 3-way here. No complaints at all.

My objective is to use the three amps for PC-based 6-channel DSP 3-way wall-mounted stereo speakers for desktop use. For now I'm using two A5s in a 4-channel 2-way DSP wall-mount system. They are on hours at a time, turned off when not in use. I couldn't be more pleased with the results, that is, the sound. I don't have another amp for comparison, but there has not been a single issue I can identify. In my case the 2-way using the Bodzio Ultimate Equalizer in my PC will be flat SPL with linear (zero) phase as well. Not measured, but I have no doubt. I had measured my main 3-way dipole system years ago that verified its zero phase using the UE.

These do get hot. I measured the case temp exterior closed top, then propped open a bit (using the idea from SoundAudio), then flipped the cover open completely. Each change reduced the external case temperature up to 5-10 degrees F depending on where I measured (lots of variability). I have no concerns about that.

I purchased the 48V power supply. Probably should have gotten the 32V one that reportedly results in much less heat generated. For desktop use that's the better option, but I thought I may use them in a floor standing setup at some point and I'd want the extra power. I don't actually need the 48V power for now. But I couldn't be more pleased with these, especially when you consider the price.

For the record these are measurements I made using REW, all are 5W into 4-ohms.

Frequency response (on unit):

Narrow vertical scale frequency response:

One thing to add. I've had to set the volume knob at the 12:00 position. The gain is way too much for desktop use. I control volume using a Topping D50III. The UE has volume control as well, but I set it max, let the D50 do all control. I have to have it at -50dBFS for casual listening if the UE is maxed.

 

[truth_soldier]

I purchased the 48V power supply. Probably should have gotten the 32V one that reportedly results in much less heat generated. For desktop use that's the better option, but I thought I may use them in a floor standing setup at some point and I'd want the extra power. I don't actually need the 48V power for now. But I couldn't be more pleased with these, especially when you consider the price.

The Topping MINI 300 uses a PSU of 38V 4A which is not common. I wonder if that is a sweet spot for voltage?
edit: sorry I think that might be using the TPA3251 a different chip.

One thing to add. I've had to set the volume knob at the 12:00 position. The gain is way too much for desktop use. I control volume using a Topping D50III. The UE has volume control as well, but I set it max, let the D50 do all control. I have to have it at -50dBFS for casual listening if the UE is maxed.

I run mine with volume pot at 100% and control the volume with a preamp. Works well. I wish there was a volume bypass switch.

 

[Douk Audio]

Hi @Douk Audio any news on the V4 release?

Sorry for the late reply. I checked with our production team today, since we just got back from the Chinese New Year holiday, the production lines are still ramping up. Plus we've still got a pretty good stock of the V3 version, so we're planning to start production on the V4 around late March, and it should be ready by mid-April.

We sincerely apologize for the delay in actual production completion compared to the estimated time.

 

[Audionaut]

since we just got back from the Chinese New Year holiday, the production lines are still ramping up

Yes, folks, you have to work too and not celebrate the Fire Horse for two weeks.
(That's a joke, in case it's not clear. I appreciate Chinese culture and its traditions.)

 

[Douk Audio]

celebrate the Fire Horse for two weeks.

Thanks for your kindness. In fact, it was three weeks.