Douk Audio TPA3255 Amplifier with HPF is Coming! Let's Shape it Together!

[john61ct]

Would LOVE to see this tested, especially comparing to Fosi v3. Would even pay for one to loan for that purpose.

Wary about direct shipping like Ali these days, any reasonably priced trusted USA source?

 

[john61ct]

I plan to use as a Power amp, fed from Schiit Syn for 5.1 home theatre. But for 2.1 music, no Active sub, any suggestions for an inexpensive Low Pass filter between the AUX OUT and the monobloc amp feeding a Passive sub?

DC only power context, I suppose I could look for yacht/RV sub rig with LPF included, JL Audio maybe?

 

[RikudouGoku]

Wary about direct shipping like Ali these days, any reasonably priced trusted USA source?

I bought mine here and was quite a bit cheaper than on Ali.

Douk Audio A5 TPA3255 Stereo Amp HiFi Audio Class D Amplifier High-pass Filter

Features HiFi Sound with Adjustable High-Pass Filter: This TPA3255 amplifier features an adjustable high-pass filter (HPF) 30-200Hz to refine mid-high frequencies while minimizing low-frequency interference. Perfect for bookshelf or passive speakers, it enhances clarity and creates a dynamic...

doukaudio.com

 

[Talisman]

This little gem has gone completely unnoticed? Hpf and pffb, the well-tested 3255 chip for less than 120 euros.
@Douk Audio why don't you send one to Amir, afraid of post-filter distortion measurements? It's much more important to have pffb and Hpf than absurdly low distortion levels, especially if you want to integrate a sub into a small room system

 

[Krampi]

Here is a great test with A5 measurements.
Thanks CPTX for the recommendation!

 

[Janutsch]

Hello all ASR members,

Recently we have launched a series of TPA3255 digital amplifiers, and we have also received a lot of feedback from audiophiles about adding high-pass filtering.
Therefore, we have done some research and designed an A5. The following are the functions and appearances that have been temporarily determined. Please take the time to have a look, share your thoughts and shape it together!

Please offer the Amp without a powerbrick to save some money. I already have enough power bricks, thank you!

 

[EJ3]

Please offer the Amp without a powerbrick to save some money. I already have enough power bricks, thank you!

As long as a correct power brick is an option.

Many only fit what they came with.
If I have something that died that uses a power brick, when it moves on (usually to someone that may be able to repair it), the power brick goes with it.

 

[Sure Not]

Hello all ASR members,

Recently we have launched a series of TPA3255 digital amplifiers, and we have also received a lot of feedback from audiophiles about adding high-pass filtering.
Therefore, we have done some research and designed an A5. The following are the functions and appearances that have been temporarily determined. Please take the time to have a look, share your thoughts and shape it together!

Here are some highlights of the A5:
1. With acrylic window design on the top just like our DAC-Q11.
2. Easy to switch the op-amps, just take off the acrylic window and no need to remove screws.
3. Three backlight colors can be displayed individually and also can be mixed freely: blue/green/orange, the color switch is inside the A5 but easy to select and mix from the window.
4. Add HPF filter, the range can be adjusted from 60Hz to 6KHz.
View attachment 395389View attachment 395390
View attachment 395391


Here are some questions that need your suggestions:
1. What range of the HPF filter adjustment is better and suitable for most audiophiles' use?
2. What power adapter is better to match with the A5 considering performance and cost performance? Below is the estimated price:
A5 with 32V5A power adapter, $79.99
A5 with 36V5A power adapter, $89.99
A5 with 48V5A power adapter, $99.99
Which one do you prefer?

Basic Function and Parameters
Audio input: stereo L/R RCA
Audio output: Banana speaker jacks / 3.5mm AUX
Max power output in theory: 300W*2 (4 ohms, THD10%)
Frequency response range: 20Hz-20kHz (±1dB)
THD+N: 0.007%
SNR: ≥110dB
Working voltage: DC 24-48V

Of course, other suggestions are also welcome. Thank you for sharing your opinions in advance!

Looks like I showed up after the party ended, but I don't see a need for a HP filter above 100hz. The 48v should be the only option, otherwise the power specs are invalidated, and people will feel scammed that they can't achieve the claimed power. Also, stop listing BS power figures (like @ 10%THD). Please make sure the aux out level is controlled by the volume knob. Also, I like the removable lid. I'm not a child, don't need to be protected from myself, and will run it without a lid for better cooling.

 

[RikudouGoku]

Please make sure the aux out level is controlled by the volume knob.

It is.

 

[EJ3]

Looks like I showed up after the party ended, but I don't see a need for a HP filter above 100hz. The 48v should be the only option, otherwise the power specs are invalidated, and people will feel scammed that they can't achieve the claimed power. Also, stop listing BS power figures (like @ 10%THD). Please make sure the aux out level is controlled by the volume knob. Also, I like the removable lid. I'm not a child, don't need to be protected from myself, and will run it without a lid for better cooling.

Other than sentence 1 (my personal subs have an FR of 20-80HZ [but I can see some people needing to the 200-250 HZ zone]),
I agree with you 100% on the rest. Especially the lid part.
But we need to be conscious of dust build up & overheating due to that. (By replacing the lid, when not in use). Failure of someone to do that will bring the nannies out in full force.

 

[Guddu]

Can anyone measure frequency response with HPF enabled to check the slope?

 

[ioskyr]

Hello, what is the amp gain?

 

[PC Audio Lover]

Finally, an adjustable HPF on an amp! (Now if all preamps would just include one... and maybe a LPF too!)

Just a few very simple missed opportunities I see on the A5 amp @Douk Audio ...

1) need hash marks every 10hz showing adjustment range on the HPF knob so you know where you're at. (Even if ultimately you measure with REW this would be helpful, especially as you are fiddling with it.)

2) Stick the HPF knob on the back, not the front. Or put some sort of feature on it that keeps it from being accidentally adjusted once set. Once someone gets that setup and blended perfectly along with their sub's LPF, they are going to be ticked if it gets accidentally adjusted when they go for that volume knob.

3) RCA for sub out /aux would be much nicer for those with good cables. No one wants to buy a crappy splitter.

4) RCAs are too close together for some cables.

Also, I would note on your product page what type of filter the HPF is. Digital/Analog? Linkwitz-Riley or... ?

But altogether, SO happy to see this product! As many new audiophiles are using desktop 2.1 systems, this has been greatly needed!!!

 

[Abstracted]

I'm a little unclear what the HPF does.
Does it pass the filtered highs (IE. >100Hz) to the speaker level outs, and full spectrum to the Aux? Or does it it pass the filtered highs (IE. >100Hz) to the speaker level outs, and pass only the lows (IE.<100Hz) to the Aux? Or is it the other way around where only the lows are passed to the Aux and full spectrum to the speaker level outs?

 

[PC Audio Lover]

I'm a little unclear what the HPF does.
Does it pass the filtered highs (IE. >100Hz) to the speaker level outs, and full spectrum to the Aux? Or does it it pass the filtered highs (IE. >100Hz) to the speaker level outs, and pass only the lows (IE.<100Hz) to the Aux? Or is it the other way around where only the lows are passed to the Aux and full spectrum to the speaker level outs?

The aux is full signal no matter the setting on the HPF knob, on or off. The HPF removes any signal from the speaker level outputs below the frequency set on the knob. (Well, that's a rudimentary explanation, there's a falloff curve, but you get it.)

 

[Abstracted]

there's a falloff curve, but you get it.

Sure do. Thanks!

 

[Abstracted]

And at this point we don't know what the SINAD is correct?

 

[PC Audio Lover]

And at this point we don't know what the SINAD is correct?

Someone might, but I don't! I'm pretty shocked at the YouTube reviews though. Pretty high praise (typically with something like Sparkos op amps added, which members of this forum might not care much about, but I'm keen to try for myself at some point.)

 

[EJ3]

Finally, an adjustable HPF on an amp! (Now if all preamps would just include one... and maybe a LPF too!)

Just a few silly mistakes I see made on the A5 amp...

1) need hash marks every 10hz showing adjustment range on the HPF knob so you know where you're at. (Even if ultimately you measure with REW this would be helpful, especially as you are fiddling with it.)

2) Stick the HPF knob on the back, not the front. Or put some sort of feature on it that keeps it from being accidentally adjusted once set. Once someone gets that setup and blended perfectly along with their sub's LPF, they are going to be ticked if it gets accidentally adjusted when they go for that volume knob.

3) RCA for sub out /aux would be much nicer for those with good cables. No one wants to buy a crappy splitter.

4) RCAs are too close together for some cables.

Also, I would note on your product page what type of filter the HPF is. Digital/Analog? Linkwitz-Riley or... ?

But altogether, SO happy to see this product! As many new audiophiles are using desktop 2.1 systems, this has been greatly needed!!!

I don't think that it needs so many hash tags (60, 80, 100, 120, 150 Hz) would likely be enough to let you know you're settings.
Particularly if there was some sort of light detents at 60, 100 & 150.

 

[Batmobil3250]

Hello, when will the A5 be available again? Rgd Mike