Douk A5 Budget Stereo Amplifier Review

[beigtapel3]

Thanks for assistance DanielT!

I'm not very good in audio theory so excuse me for dumb questions.

Let me bring it this way:
I have Monitor 3 speakers, Paradigm recommends an amp between 15-150W and they're rated at 100W max input power. The above chart (not sure if it's even accurate) explains why I must bring the volume knob up to almost 90% to get the max SPL out of them. Is AI correct and the true reason why I can achieve same SPL on Denon PMA860 with volume knob at just 40% is because of the difference between A5's input sensitivity (2V) vs Denon (0.150V means the 2V input signal is 13 times higher & helps to achieve same SPL at lower amplification state)?
Theoretically if I decide to hook up a pair of Monitor 11 (15-250W amp recommended, max input power rating of 180W), I should still be able to achieve near-limit SPL (without taking improved speaker sensitivity into account, which helps)? I'm talking about raw power & SPL, not taking THD into account (I understand those 2x185W are very optimistic numbers and it distortion will raise much faster).



I was just concerned there's something wrong with the AMP/PSU and I'm not getting a full power as 2x less powerful amp was able to max out the speakers at much lower amplification state.

 

[DanielT]

The position of the volume knob isn't something to get hung up on—for the reasons you mentioned, like logarithmic scaling and so on. Assuming your gear is working correctly and the Douk A5 is receiving the maximum input voltage, well, that’s simply the performance you get. If you have the Douk A5 set to max volume, that’s the output you get. It is what it is.

I see your speakers support bi-amping.

You have two amplifiers. Try splitting the signal (using an RCA splitter, for example) and let the Denon amp handle the woofer while the Douk A5 handles the tweeter. You might like that setup. It might be unnecessary, but since you have the gear, you could give it a try—just for the fun of it.

Edit:
If you have a small laptop power supply lying around at home, ..

...try it out. Your Douk A5 will be low-power compared to the PSU you're currently using.
See if you notice any major difference in the Douk A5's output power.

 

[beigtapel3]

Monitor 3 doesn't support bi-amping, and I don't own Monitor 11 (I just used them as an example to test my theory). Now you understand my (lack of) knowledge in audio technicalities. But I got a small bit smarter today. Thank you Daniel for being here and not ignoring a newbie asking stupid questions. Will keep enjoying my setup and sleep tight knowing there's nothing wrong with it.

 

[Power Pop 23]

The 'Nobsound Official Store' on Ebay offers the Douk Audio A5 Amplifier without a power supply unit for $58.49 with an additional discount on purchases of more units.

https://www.ebay.com/itm/135769117230?

 

[truth_soldier]

.
A new review out (presumably on the V4 A5).
I like this guy's reviews compared to most out there...
Although warning for ppl here, it's mostly subjective... no charts or measurements.
.

 

[dex]

Greatings all, I am new in this forum and this is my first post. I have a douk a5 and my first impression was, it is HOT! I use a 48V 10A GaN psu from a 3e Audio A7 and it works fine but the temperature..too hot. O.K. I reduced the volume to 80-90 %, pulled off the rubber knobs (rubber is evil) and put it ontop of my Golden Age Pre-73 MKii. The huge metal case takes the heat very nicely (metal is good). I had a very small usb ventilator and putted him on the side of the douk/pre-73 combo. A soft air flow and the douk a5 gets just lukewarm, even under heavy work. I hope I could help with my workaround

The next episode...I changed the original thin cables (connected over blank wires) from my speakers to some thicker standard dynavox cables and all the heat is gone. Am I going nuts ? Anyway I like this physical effect

 

[truth_soldier]

FYI, for those who haven't already seen the Douk Audio H5 tube preamp they made to mate with the A5 amp:

Douk Audio H5 Tube Preamp with LPF & HPF-designed specifically for A5

Hello All ASR Members, It's been nearly two years since the release of the Douk Audio A5. A big thank you to all ASR members for your valuable feedback and contributions to the A5. After the A5 became popular, we received many requests from customers asking for a matching preamp. So today...

www.audiosciencereview.com

 

[truth_soldier]

FYI, ran across this ventilated lid replacement design that you can have 3D printed - if it hasn't been posted here before...

https://www.printables.com/model/1788422-douk-a5-replacement-ventilated-lid

 

[WasteLand]

via the Douk Audio shop itself, you can get the Douk Audio A5 with a 36v/5a or a 48/5a power supply for $72 or $88 (or so). 20% discount, 6 days, i believe are left for this discount.

you can choose from which country or region the A5 will be shipped (EU for instance, or US or UK....).

which means, i am in the EU, it is shipped within EU, and you pay, yes yes $88 for instance... amazon, for my country, is twice as much....

it is nicely running hot next to me, as an amp for my passive studio monitors (Yamaha NS-40M STUDIO).

 

[truth_soldier]

@Douk Audio

here's an idea for a new product or a revised version of the A5...

Instead of a high-pass filter and manual front control-knob, build a programmable DSP into it so the amp can be configured via software (PC USB-C connected) to be either low-pass, high-pass, or both, or configured full-range with room correction applied.

An example here is the low cost Wondom BRU5 (User Manual), which uses the MV Silicon BP1048B2 SoC for DSP and configuration app for Windows.
But I think Douk could make a better performing amp with that MV Silicon DSP chip. [BRU5 thread on ASR]

A Douk Audio A5 and/or Ampapa D1 with built-in DSP would be a killer product I think.
Ideally a low cost A5 with DSP would be great (stereo or mono) so people can buy multiple for use in bi-amping speakers, subwoofer amps, etc.

what do y'all think?

 

[GGroch]

A Douk Audio A5 and/or Ampapa D1 with built-in DSP would be a killer product I think.
Ideally a low cost A5 with DSP would be great (stereo or mono) so people can buy multiple for use in bi-amping speakers, subwoofer amps, etc.

Hi Truth. There are trade offs when using MV Silicon and the like. Those chips are designed for use in things like Kiosks and Soundbars where simple topology and DSP functions are valued over measured specifications. There is a major hit in S/N and distortion. I'm a Bru5 owner and fan, and think the trade of is often worth it. But, Douk/BRU5 would no longer be a Douk A5 in pure performance.

The Fiio Jade Audio Level One amp does manage the good specs, useful DSP trick. Gemini tells me it uses a more sophisticated Bluetrum BT8961 Bluetooth USB/DSP Engine. So, it is certainly possible and I hope we see more of it. It seems though that this kind of DSP is showing up in more and more DACs, and perhaps it makes sense to put it there.

 

[truth_soldier]

There is a major hit in S/N and distortion. I'm a Bru5 owner and fan, and think the trade of is often worth it. But, Douk/BRU5 would no longer be a Douk A5 in pure performance.

Thanks! Digging I saw there is some loss of fidelity via the ADC but it's not horrible...
"The analog signal enters the BP1048B2 chip, where the internal Analog-to-Digital Converter converts it into a digital signal (capped at 24-bit / 48kHz with a 94dB SNR limit)" ... then after that it does DAC back to analog at a higher SNR of 104dB before sending to the TPA3255, but of course every conversion potentially degrades the signal quality.

I wonder if this would still work OK for my purpose of bass-amp in a bi-amp config... or if the processing will delay the signal and cause the bass to be out of phase?

 

[john61ct]

DSP really is the way to go for phase tuning, ToA delay flexibility.

But try and see with analog crossovers, might be just fine - trust your ears

Even if you use REW to verify

 

[john61ct]

DSP is showing up in more and more DACs, and perhaps it makes sense to put it there.

DDC, DACs and HPamp combo units WITH PEQ/DSP

There is these days a lot of excitement around Topping DX1 II both positive about the value pricing combined with stellar objective measurements and many reports of implementation faults that hopefully will get corrected with firmware updates. The topic of this thread is OTHER units that are...

www.audiosciencereview.com

 

[truth_soldier]

DDC, DACs and HPamp combo units WITH PEQ/DSP

There is these days a lot of excitement around Topping DX1 II both positive about the value pricing combined with stellar objective measurements and many reports of implementation faults that hopefully will get corrected with firmware updates. The topic of this thread is OTHER units that are...

www.audiosciencereview.com

DSP in the DACs is great for some uses but doesn't help the bi-amping use case that I'm after.
And doing low-pass in analog with big inductors is an inferior solution. You have less adjustment flexibility for dialing in the sound and for less than the cost of a pair of heavy inductors (plus shipping) you can buy a low cost class-d amp with DSP built in (like the BRU5).

 

[john61ct]

I'm happy to pay a bit more for a unit that stays at line level, any reco?

 

[Douk Audio]

@Douk Audio

here's an idea for a new product or a revised version of the A5...

Instead of a high-pass filter and manual front control-knob, build a programmable DSP into it so the amp can be configured via software (PC USB-C connected) to be either low-pass, high-pass, or both, or configured full-range with room correction applied.

An example here is the low cost Wondom BRU5 (User Manual), which uses the MV Silicon BP1048B2 SoC for DSP and configuration app for Windows.
But I think Douk could make a better performing amp with that MV Silicon DSP chip. [BRU5 thread on ASR]

A Douk Audio A5 and/or Ampapa D1 with built-in DSP would be a killer product I think.
Ideally a low cost A5 with DSP would be great (stereo or mono) so people can buy multiple for use in bi-amping speakers, subwoofer amps, etc.

what do y'all think?

Hello, thank you for your new suggestion regarding the A5!

I have passed your suggestion on to our product development team; they will carefully review and consider your ideas. I will share any updates here as soon as I have them.

Thanks again!

 

[Birdy]

@Douk Audio

here's an idea for a new product or a revised version of the A5...

Instead of a high-pass filter and manual front control-knob, build a programmable DSP into it so the amp can be configured via software (PC USB-C connected) to be either low-pass, high-pass, or both, or configured full-range with room correction applied.

An example here is the low cost Wondom BRU5 (User Manual), which uses the MV Silicon BP1048B2 SoC for DSP and configuration app for Windows.
But I think Douk could make a better performing amp with that MV Silicon DSP chip. [BRU5 thread on ASR]

A Douk Audio A5 and/or Ampapa D1 with built-in DSP would be a killer product I think.
Ideally a low cost A5 with DSP would be great (stereo or mono) so people can buy multiple for use in bi-amping speakers, subwoofer amps, etc.

what do y'all think?

The HP filter on my Douk A5 works great for me, i run it on 50 Hz and use a cheap car DSP set at 48 dB / 50 Hz with a Aiyima 07 to drive a subwoofer at 2.7 ohm. This works great for me but with DSP in a Douk A5 i could start going active in my main speaker with 3x Douk A5 without the passive crossover. Would cost a bit though!
Bye the way, the Douk A5 is a great amplifier with superb sound! I had a class A DC coupled tube amp 0,35% THD and low impedance output, but this little Douk is overall the winner.

 

[Volkov1943]

Hello to everyone. I'm new to this forum and the whole audio stuff. So still finding the ropes I have bought A5 with 48/5 brick and paired it with Arylic BP50 (ARC is a must as movies are primary use), Yamaha NX-E800 Pianocraft speakers and Canton As120mx sub connected to BP50 with Hpf on85hz.

Since I have ordered it directly from Douk last month, apparently I got Version 4.
Here are some pics

 

[Volkov1943]

Just some add on:

It gets warm while working but nothing dramatically. Temperature is even on whole chassis, no hotspots. And apparently it have some kind of standby. When you cut input signal after some time even as led lights are on it gets cold or room temperature. Left it over night turned on and it was cold in the morning. Also no pop or clicks on Dac turning off. I was originally planning to automate turning on/off proces with two smart plugs but now thinking there is no need.