Douk Audio A100 [TPA3255 PFFB Mono/Stereo] - User Impressions | Owner's Thread

[Guddu]

Dear FMs,

Douk Audio posted a thread about this A100 amplifier HERE sometime back and they shared loads of information with internal pics, measurements like SINAD and power output.

I have recently got Douk Audio A100 amplifier, as I continue with my enthusiasm to explore TPA3255 chip amplifiers, and I have found this amplifier different than others in many ways.
This thread is dedicated to Douk Audio's new TPS3255 amplifier, I intend to share my impressions using this amplifier testing and evaluating features with observating any issues if noticed.
I hope other A100 owners may chime in as well to share their observations, used cases and any issues (if any).

*** I hope other A100 owners can also sum up their feedback and some work arounds here to help other potential owners or interested ones ***

Here, I mean to summarize:
> what I get as a buyer or user of Douk Audio A100 amplifier
> aspects other than measurements that you might be interested in
> testing features & functions to see if there are any issues and how could get around those, if any
> I also hope that this thread could provide some information as to "what to expect" while you look to buy one for yourself

Price (as of 08/08/2024)
* Amazon and Douk's store - 199$ with 48v 5a PSU
* AliExpress - 164.99$ (after 25% off) without PSU, and 202.49$ (after 25% off) with 48v 5a PSU

Package Contents
* Amplifier unit, PSU/power cable and laminated user manual

- Note that power plug detached cord is 20AWG while DC cable attached to PSU is 18AWG

- They have done great job providing Laminated user Manual, which has all the details you might need and even more

- They even included SINAD measurements and frequency response. This is PFFB topology implementation so both the measurements are as good as others with PFFB.

Case Work
- The case is super solid, all aluminium, think and heavy
- Top has thick fins, however sides and bottom had less defined fins
- Front has brushed aluminium touch along with some partly smoother finish
- Honestly, pics don't reallt justify the asthetics but it looks much better in person than pics
- Note the height of the amplifier is twice+ than others we have seen from Aiyima (like A07 pro, max), Fosi (v3 and v3 mono), Topping PA5 II or PA7 etc.
- Front has selection toggle switches and potentiometer knobs for different adjustments, more details later in the post

- Back has rather simplified connections - RCA input, aux out, speaker terminals and PSU input
- the speaker terminals are much better than other amplifiers (similar to Topping PA7, Aiyima A07 Max, Aiyima A70 etc.)

Summarising input/output on this amplifier:
Note: I wasn't going to detail this part but it took me some time to read and understand this, so thought someone might use these short cliff notes to get it quickly
- Single ensed or un-balanced RCA inputs only, however no balanced inputs
- RCA input sensitivity: 2v (update)
- Aux out with full band or sub-frequency out, however no sub-out
- Aux out: 2.8v (update)
- Amplifier can function as:
- Stereo/Mono amplifier with full frequency - by selecting first toggle (left) to MONO/STEREO and second toggle (right) to FLAT
- The FLAT mode enabled 2 potentiometer knobs on front, which worked fine with me trying a few times
- 4th knob from left or last one on right - VOLUME - Contols the volume out to speaker output, it had no effect on aux out
- Stereo/Mono Subwoofer Amplifier with low/mid-low frequency - by selecting first toggle (left) to MONO/STEREO and second toggle (right) to SUB
- The SUB mode enabled 2 potentiometer knobs on front, which worked fine with me trying a few times
- 1st knob from left - SUPER-BASS - no markings on the amplifier but it is adjustable -6dB to +6dB BASS
- 2nd knob from left - SW-FREQ - no markings on the amplifier but it is adjustable from 50 - 220 Hz
- Pre-amp with Aux Out
- Aux Out is full band out
- 3rd knob from left (in front) controls and adjusts the volume output to Aux Out

Idle Power Consumption
- A100 used about 9-10 watts when IDLE, connected and powered ON but no sound playing
- measured on 20A smart power plug

Case Heating & Tempreture - Better than others (updated)
- The amplifier case remain cool on idle, this is unlike any other TPA3255 amplifier I have (and believe you me that I have many of those)
- I have Ascend Sierra-lx hooked up to A100, which do play lower base frequencies and eats up some good power, and amplifier case did get just warm to touch in playing quite loud to longer period
- Whatever Douk Audio did, working on this amplifier with better thermal performance. This amplifier is running cool or just warm in my setup while other amps are running towards hotter side in same setup
- This also makes me believe that this amplifier can easily be used for passive subwoofer, thermal performance of this amplifier is best so far (to me)

Hiss/Noise and Pop Sound on Power ON/OFF
- NO HISS or any noise at all on FULL Volume position to my speakers, nothing on putting ear to tweeter
- NO POP sound on power ON/OFF toggle switch
- So this amplifier is handling these common issues much better than other TPA3255 amplifiers I have owned

My Setup

nVidia Shield & Laptop >>>> Emotiva xmc-1 Gen2 >>>>>RCA>>>>> Douk A100 amplifier >>>>> Ascend Sierra-lx speakers

Subjective Impressions
- Very clean and balanced sound with very clear stereo separation
- Sound is really strong, lower volume had similar attributes as higher volume
- No complains at all... only praises
- Here is quick REW sweep for Douk A100 vs Topping PA7:

Some Notes and considerations:
- The RED LED in front is thankfully quite mild, does not cause any disturbance.
- I am listening A100 in stereo mode most of the time as I have got only 1 unit, however 2 x mono setup would be amazing as well!
- The case edges are a bit sharp, and so requires a bit careful handling. Slighly softer and smooth edges would have been nice.
- The bottom could use 2-3 cm high feets to provide some clearence on bottom, I would surely use some feets myself and would sugget to others as well (4 small silicon spacers are included in the package but i think slighly bigger would make more sense).
- SUPER-BASS and SW-FREQ knobs in front has no number marking, this had made it difficult to get to any approx. specific value. I wish if they could have put a dot for every 10dB variance or something to make it easier to adjust and avoid kind of confusion.
- I feel that the stock AC power cord (20AWG) is thin to use with 48v 5a psu and this amplifier, I am using a different 18AWG AC cord and it matches with DC cord part of stock PSU. Douk should upgrade the AC cord for safer operation. (some corrections made)
- Power input port has marking 24 - 48v, however @Douk Audio provided 51v psu measurements running the amplifier to its peak. Probably Douk Audio are not suggesting to use anyting above 48v?
- The amplifier case is completely closed, no airflow possibility through it. TPA3255 Chip is screwed to bottom and using case as radiator but wouldn't some ventilation help for heat build up inside for other components!

A few suggestions @Douk Audio
What did I miss most! <having these makes it easy to integrate the amplifier within a setup, kind of must to have these days>
- Volume bypass
- Triggered input or auto ON/OFF

Something for a different amplifier: @Douk Audio
- A simpler mono/stereo power amplifier version of this A100 would suit many scenarios very well.
- I really think the same case with no no buttons/knobs in front, or just power toggle would look very good. The knobs on A100 aren't totally matching with brushed aluminium look behing it.
- Same thermal performance, and same filters avoiding hiss or any pop sound on power ON/OFF.
- No volume control, no SUB mode, aux out or sub out - may be, no tone controls.
- A 3 or 4 channel power amplifier version of this A100 is something everyone is asking other vendors, probably you should look at that.

 

[Graham849]

Thank you for that review. I got tired of waiting so I'm enjoying a Fosi ZA3.

 

[Bruce Morgen]

Douk Audio A100 TPA3255 Digital Power Amplifier Mono/Stereo Bass Audio Amp 300W now on eBay for $163.99 (USD).

 

[burkm]

My impressio: It looks quite "cheap" in its current appearance and the measurements shown are "not so good"... Who "designed" that as is ???
It might have a better temperature management as the Fosi Audio V3 mono but still lacks some escape possibilities for enclosed (hot ?) air at the top.
Due to its lower temperatures this might not be as problematic as on the Fosi Audio V3 mono...

 

[Guddu]

Many youtube reviews now for this Douk A100, a few with some comparision with other similar products.
Subjectivists are appreciating A100.
Looks like a few used the idea of using fins block on top of their (other brand) amplifiers to help with temp. control!

 

[Kagemusha]

This amp in Amazon is 250€ , with all respect, there is no way I would buy this for that money, and has no got so good reviews either, and is not so nice to look at.

 

[Bruce Morgen]

This amp in Amazon is 250€ , with all respect, there is no way I would buy this for that money, and has no got so good reviews either.

There's way too much competition in the TPA3255 chip amp marketplace for this thing to stand out at that price point.

 

[Guddu]

After seeing Douk PFFB performance on A5’s review recently, this might interest a few as well:

 

[Sigfried]

There's way too much competition in the TPA3255 chip amp marketplace for this thing to stand out at that price point.

I just picked another one up 2 weeks ago. The first i got on the introductory bargain price. That cost me $90 including shipping. I went back to see if they are possibly having any other sales on these since these can be run in mono. Low and behold they were offering it for $99 and also with 10% off. So I got two of them now for $180 which included shipping. I have yet to check out the mono function/sound but that will happen eventually. For now, one is in my living room and one at my desktop. I have the original Fosi V3 and to my ears this bested it. The V3 is a great amp however and may suit some with different setups. Nobsound is where i purchased it.Just checked and they still have it for $99. Does it sound better than the A5? Dunno. But i can tell you that it is built like a tank with that heatsink. Not a fan of the A100's aesthetics but it sounds great and has better mid presence in my setup than the V3. I feel NO need to be tinkering with the opamps as it sounds excellent as is to me. Apparently that is a good thing as they aren't tje easiest to get to from what i have read. Would love to hear what the 3E A5 sounds like!! I"ve spent enough now on these however. Next move is to set them up in mono to see what that brings to the table.

 

[Sigfried]

I just picked another one up 2 weeks ago. The first i got on the introductory bargain price. That cost me $90 including shipping. I went back to see if they are possibly having any other sales on these since these can be run in mono. Low and behold they were offering it for $99 and also with 10% off. So I got two of them now for $180 which included shipping. I have yet to check out the mono function/sound but that will happen eventually. For now, one is in my living room and one at my desktop. I have the original Fosi V3 and to my ears this bested it. The V3 is a great amp however and may suit some with different setups. Nobsound is where i purchased it.Just checked and they still have it for $99. Does it sound better than the A5? Dunno. But i can tell you that it is built like a tank with that heatsink. Not a fan of the A100's aesthetics but it sounds great and has better mid presence in my setup than the V3. I feel NO need to be tinkering with the opamps as it sounds excellent as is to me. Apparently that is a good thing as they aren't tje easiest to get to from what i have read. Would love to hear what the 3E A5 sounds like!! I"ve spent enough now on these however. Next move is to set them up in mono to see what that brings to the table.

I will add that the volume knob is indeed wonky. I like the smoothness of the V3's without a doubt over the A100's. That being said, for me it is a set it and forget it type thing. The sound is superior for me and that is what matters. I will most likely having both in use as mono blocks and behind the speakers out of site and both set at a certain level and then forgotten about.Volume control will be done by an Eastern Electric Minimax Tube preamp. A match made in heaven with these small class D amps! HIGHLY recommended putting tubes in front of them regardless of the distortion measurements. It just plain sounds sooooo much better TO MY EARS(Height/Width/Depth) with it in place.

 

[Guddu]

But i can tell you that it is built like a tank with that heatsink. Not a fan of the A100's aesthetics

It surely is build like a tank, heavy and heatsink doing its job.
I have seen people now sticking similar after market heatsink on Fosi v3 mono etc. which kind of makes them look only worse for little or no added benefit. But there is surely some value is doing what @Douk Audio did with their A100.
Their documentation shows around 94 dB SINAD in their measurements for RCA input, so I would safely assume that A100 should have even better performance just by seeing those numbers....

 

[redjr]

Dear FMs,

Douk Audio posted a thread about this A100 amplifier HERE sometime back and they shared loads of information with internal pics, measurements like SINAD and power output.

I have recently got Douk Audio A100 amplifier, as I continue with my enthusiasm to explore TPA3255 chip amplifiers, and I have found this amplifier different than others in many ways.
This thread is dedicated to Douk Audio's new TPS3255 amplifier, I intend to share my impressions using this amplifier testing and evaluating features with observating any issues if noticed.
I hope other A100 owners may chime in as well to share their observations, used cases and any issues (if any).

*** I hope other A100 owners can also sum up their feedback and some work arounds here to help other potential owners or interested ones ***

Here, I mean to summarize:
> what I get as a buyer or user of Douk Audio A100 amplifier
> aspects other than measurements that you might be interested in
> testing features & functions to see if there are any issues and how could get around those, if any
> I also hope that this thread could provide some information as to "what to expect" while you look to buy one for yourself

Price (as of 08/08/2024)
* Amazon and Douk's store - 199$ with 48v 5a PSU
* AliExpress - 164.99$ (after 25% off) without PSU, and 202.49$ (after 25% off) with 48v 5a PSU

Package Contents
* Amplifier unit, PSU/power cable and laminated user manual
View attachment 385599
View attachment 385621
- Note that power plug detached cord is 20AWG while DC cable attached to PSU is 18AWG

View attachment 385622

- They have done great job providing Laminated user Manual, which has all the details you might need and even more

View attachment 385601
View attachment 385602

- They even included SINAD measurements and frequency response. This is PFFB topology implementation so both the measurements are as good as others with PFFB.

View attachment 385603

Case Work
- The case is super solid, all aluminium, think and heavy
- Top has thick fins, however sides and bottom had less defined fins
- Front has brushed aluminium touch along with some partly smoother finish
- Honestly, pics don't reallt justify the asthetics but it looks much better in person than pics
- Note the height of the amplifier is twice+ than others we have seen from Aiyima (like A07 pro, max), Fosi (v3 and v3 mono), Topping PA5 II or PA7 etc.
- Front has selection toggle switches and potentiometer knobs for different adjustments, more details later in the post
View attachment 385607

- Back has rather simplified connections - RCA input, aux out, speaker terminals and PSU input
- the speaker terminals are much better than other amplifiers (similar to Topping PA7, Aiyima A07 Max, Aiyima A70 etc.)

View attachment 385611

Summarising input/output on this amplifier:
Note: I wasn't going to detail this part but it took me some time to read and understand this, so thought someone might use these short cliff notes to get it quickly
- Single ensed or un-balanced RCA inputs only, however no balanced inputs
- RCA input sensitivity: 2v (update)
- Aux out with full band or sub-frequency out, however no sub-out
- Aux out: 2.8v (update)
- Amplifier can function as:
- Stereo/Mono amplifier with full frequency - by selecting first toggle (left) to MONO/STEREO and second toggle (right) to FLAT
- The FLAT mode enabled 2 potentiometer knobs on front, which worked fine with me trying a few times
- 4th knob from left or last one on right - VOLUME - Contols the volume out to speaker output, it had no effect on aux out
- Stereo/Mono Subwoofer Amplifier with low/mid-low frequency - by selecting first toggle (left) to MONO/STEREO and second toggle (right) to SUB
- The SUB mode enabled 2 potentiometer knobs on front, which worked fine with me trying a few times
- 1st knob from left - SUPER-BASS - no markings on the amplifier but it is adjustable -6dB to +6dB BASS
- 2nd knob from left - SW-FREQ - no markings on the amplifier but it is adjustable from 50 - 220 Hz
- Pre-amp with Aux Out
- Aux Out is full band out
- 3rd knob from left (in front) controls and adjusts the volume output to Aux Out

Idle Power Consumption
- A100 used about 9-10 watts when IDLE, connected and powered ON but no sound playing
- measured on 20A smart power plug
View attachment 385615

Case Heating & Tempreture - Better than others (updated)
- The amplifier case remain cool on idle, this is unlike any other TPA3255 amplifier I have (and believe you me that I have many of those)
- I have Ascend Sierra-lx hooked up to A100, which do play lower base frequencies and eats up some good power, and amplifier case did get just warm to touch in playing quite loud to longer period
- Whatever Douk Audio did, working on this amplifier with better thermal performance. This amplifier is running cool or just warm in my setup while other amps are running towards hotter side in same setup
- This also makes me believe that this amplifier can easily be used for passive subwoofer, thermal performance of this amplifier is best so far (to me)

Hiss/Noise and Pop Sound on Power ON/OFF
- NO HISS or any noise at all on FULL Volume position to my speakers, nothing on putting ear to tweeter
- NO POP sound on power ON/OFF toggle switch
- So this amplifier is handling these common issues much better than other TPA3255 amplifiers I have owned

My Setup
View attachment 385618
nVidia Shield & Laptop >>>> Emotiva xmc-1 Gen2 >>>>>RCA>>>>> Douk A100 amplifier >>>>> Ascend Sierra-lx speakers

Subjective Impressions
- Very clean and balanced sound with very clear stereo separation
- Sound is really strong, lower volume had similar attributes as higher volume
- No complains at all... only praises
- Here is quick REW sweep for Douk A100 vs Topping PA7:

Some Notes and considerations:
- The RED LED in front is thankfully quite mild, does not cause any disturbance.
- I am listening A100 in stereo mode most of the time as I have got only 1 unit, however 2 x mono setup would be amazing as well!
- The case edges are a bit sharp, and so requires a bit careful handling. Slighly softer and smooth edges would have been nice.
- The bottom could use 2-3 cm high feets to provide some clearence on bottom, I would surely use some feets myself and would sugget to others as well (4 small silicon spacers are included in the package but i think slighly bigger would make more sense).
- SUPER-BASS and SW-FREQ knobs in front has no number marking, this had made it difficult to get to any approx. specific value. I wish if they could have put a dot for every 10dB variance or something to make it easier to adjust and avoid kind of confusion.
- I feel that the stock AC power cord (20AWG) is thin to use with 48v 5a psu and this amplifier, I am using a different 18AWG AC cord and it matches with DC cord part of stock PSU. Douk should upgrade the AC cord for safer operation. (some corrections made)
- Power input port has marking 24 - 48v, however @Douk Audio provided 51v psu measurements running the amplifier to its peak. Probably Douk Audio are not suggesting to use anyting above 48v?
- The amplifier case is completely closed, no airflow possibility through it. TPA3255 Chip is screwed to bottom and using case as radiator but wouldn't some ventilation help for heat build up inside for other components!

A few suggestions @Douk Audio
What did I miss most! <having these makes it easy to integrate the amplifier within a setup, kind of must to have these days>
- Volume bypass
- Triggered input or auto ON/OFF

Something for a different amplifier: @Douk Audio
- A simpler mono/stereo power amplifier version of this A100 would suit many scenarios very well.
- I really think the same case with no no buttons/knobs in front, or just power toggle would look very good. The knobs on A100 aren't totally matching with brushed aluminium look behing it.
- Same thermal performance, and same filters avoiding hiss or any pop sound on power ON/OFF.
- No volume control, no SUB mode, aux out or sub out - may be, no tone controls.
- A 3 or 4 channel power amplifier version of this A100 is something everyone is asking other vendors, probably you should look at that.

@Guddu - What an excellent review of this amplifier. Like more and more of the CiFi audio brands, Douk has expanded and IMPROVED their product line in many aspects over the past few years. They continue to do so. I have seriously looked at Douk's offerings in the past, and was intrigued when the A100 came out last year. Perhaps I will have another change to consider this amp down the road. As you note, this amp seems to be dead silent with the volume at MAX. One of my first test, is to listen for any hiss or crackling - however low it might be - to gauge the real quality of any amp. My latest choice for a little amplifier swapping has been the Aiyima 07 Max - used in dual mono configuration. My only Douk product at the moment is the dual DAC-Q11 - which is a worthy little DAC device to play with. I have both Topping PA5 II and Fosi V3 amps which perform excellently as well.

Again, thanks for the review and I'm glad you're enjoying the A100 and it's providing you with beautiful music.