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

[Zek]

I wonder what advantages a pure TPA3255 mono amplifier offers at all.

More current and the ability to drive lower impedance speakers.

 

[antcollinet]

Thank you, this also explains the almost equal output power for each channel in the mono-only devices compared to the stereo devices. I was assuming the usual circuit designs that I know.
I wonder what advantages a pure TPA3255 mono amplifier offers at all.

The mono amplifiers usually use the PBTL mode in which the two bridged pairs are connected in paralell. This gives higher current capability, allowing use with lower impedance speakers.

EDIT : Ninjad by @Zek


I've just checked @Krampi and there are two mode pins that are set differently between BTL and PBTL - so it is not possible to run a stereo BTL amp in PBTL.

 

[Audionaut]

More current and the ability to drive lower impedance speakers.

Doesn't that largely depend on the power supply, which is external and largely variable with these amplifiers anyway?

There shouldn't be much difference between a mono with 32V 5A and a 48V 10A stereo amplifier, or am I missing something again?

 

[antcollinet]

Doesn't that largely depend on the power supply, which is external and largely variable with these amplifiers anyway?

There shouldn't be much difference between a mono with 32V 5A and a 48V 10A stereo amplifier, or am I missing something again?

You're missing something again.


Lets say the stereo amp with a 10A supply can deliver 4A per channel (limited by the amp output stage)

Then put those two stages in parallel in a mono configuration, and it can output 8A

 

[Audionaut]

You're missing something again.

Yes, I'm slowly (very slowly) getting close to the miracles of TPA3255

So to summarize, one could write that,
if the power supply is powerful enough, a stereo TPA3255 can deliver similar overall performance to two mono PBTL TPA3255. The main differences lie in the current distribution and impedance stability. If you want to drive speakers with 2 Ω or extremely low impedance, you are safer with a mono PBTL amplifier. If you only want to buy one device, you can achieve a largely similar performance with a stereo amplifier and a powerful power supply.

 

[antcollinet]

Yes, I'm slowly (very slowly) getting close to the miracles of TPA3255

So to summarize, one could write that,
if the power supply is powerful enough, a stereo TPA3255 can deliver similar overall performance to two mono PBTL TPA3255. The main differences lie in the current distribution and impedance stability. If you want to drive speakers with 2 Ω or extremely low impedance, you are safer with a mono PBTL amplifier. If you only want to buy one device, you can achieve a largely similar performance with a stereo amplifier and a powerful power supply.

Pretty much. The mono version will normally be specified with slightly higher power - but not that significantly - see comparison between the A7se and A7 mono here.

 

[RikudouGoku]

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

The only measurements I have seen is from the manual.

 

[Batmobil3250]

Doesn't that largely depend on the power supply, which is external and largely variable with these amplifiers anyway?

There shouldn't be much difference between a mono with 32V 5A and a 48V 10A stereo amplifier, or am I missing something again?

Try to multiply 32x5 and 48x10 that gives you 160 watt and 480 watt volt x ampere = watt. In this case this is how much the brick can supply. The amp has probably a current limiter set aroun 10 amp.

 

[EJ3]

Here is my setup(s).

View attachment 424517
(drawn with this https://excalidraw.com/)

I have my music files on my NAS (Synology DS423+ and another Orange Pi 5 Plus) that is setup using Navidrome as a music server and I stream to my PC or Phone.

Plan to get a sub (probably Cambridge Audio Minx X301) for my Swan Oasis 140 as I doubt it can do sub-bass well on its own.

The system in my home needs to be conducive to use by my 91 year old (astute & healthy) mother when she comes by & my wife.
Meaning the complexity has limits.
The 2 mains (Dahlquist M-905's) are powered by 1 NAD 2200 in stereo (4 OHM's around .5 Kwatts each.)
The 2 subs are built by me and powered externally by a bridged mono NAD 2200 each (4 OHM's around 1 Kwatts each)
The 2 things that you have that I want to do is a NAS & a PC with Linux Mint.
Obviously you like the Mint & that is what has been recommended to me.
It will be a learning curve, I understand, coming from the use of Windows since 2001.
And it will be after May, possibly mid-June before I will be able to start that learning curve.

 

[Batmobil3250]

@Douk Audiio
Has the a5 been such a success that it is completely sold out? It even disappeared from my shopping cart on aliexpress.
it's spooky! after a few hours It's back in the cart!

The Douk A5 should be able to ship in the week starting with Monday Feb 17. I find Douks business policy a bit rude. I also had an A5 in my basket that disappeared. It also disappeared in my basket on Douks webshop. I then got an email that I could order the A5 but without any info about availability. I asked in the chat but didnt get an immditaly reply. I asked in the group and Douk don’ rely here either. Later I got an email I could just order the product. So I did but they also took cashed the payment before even having a A5 ready to ship. I will suggest Douk to be more transparent about availability and stop cashing payments when the products is not ready yet to ship. In business term we use words like “pre-order pre payment”, “Preorder” etc.

 

[bolo_nz]

The A5 is now back on aliexpress with the option to buy without a power brick!

 

[Batmobil3250]

The A5 is now back on aliexpress with the option to buy without a power brick!

Yes as suggested to them but also with an option to buy the 48v/5a brick. At least that was the option in the email I received and acted upon.

 

[bolo_nz]

Hello all friends, thank you for your attention to our A5 amplifier and sorry for my late response since we just got back to work from our Spring Festival Holiday yesterday.
If you have any ideas or suggestions, please feel free to share them here. We will organize and feedback them to our development team to determine whether they are feasible. Thank you again!

Are there any plans to make a integrated unit by combining the A5 with a DAC (something like the SMSL PS200 in capability and function)? Surely there are people like me who don't want to stack so many boxes and having a mess of cables.

HPF (digitally adjustable) + if enough people ask for it maybe adjustable LPF + DAC with USB/SPDIF input = Perfect all in one solution

 

[Hellboy.]

Hello all friends, thank you for your attention to our A5 amplifier and sorry for my late response since we just got back to work from our Spring Festival Holiday yesterday.
If you have any ideas or suggestions, please feel free to share them here. We will organize and feedback them to our development team to determine whether they are feasible. Thank you again!

Like other person suggest "add marks every 10hz (or 20hz) showing adjustment range on the HPF knob so you know where you're at".
Right now is unusable.

 

[PC Audio Lover]

@Douk Audio take that high pass filter and put it into a simple, quality preamp now! Like the new Fosi Audio P4 but with your HPF instead of those useless tone controls. Guarantee would move a ton of those to all the new desktop 2.1 audiophiles that already have an amp they are happy with.

 

[Brian Steele]

I purchased and received an Douk Audio A5 from Amazon a few days. Nice little amp. Purchased it for testing purposes and to run my little PA speakers every now and then. My only peeves so far are: (1) 32V PSU is the only option offered for it off of Amazon, (2) The clear acrylic top cover can't be fastened into place (which means I'll have to rig up something - until that happens I've left the peel-off sticker in place), (3) the volume control knob is basically useless until rotated past the 9 o'clock position. I also thought it sounded a little on the dull side when I first hooked it up, and no I didn't see the published FR curve before forming that impression, and I'm under no impression that my 60-year old ears can hear up to 20 kHz anyway. I've been listening to it for a few hours now however and it seems like a solid little amp. Pretty tight bass too. And I did have my doubts about it, but that variable high-pass filter has turned out to be very useful. My test speakers are a pair of DIY ones I put together a few years ago. They're rather insensitive (designed for nearfield use), and at no time did I feel the need to use a more powerful PSU with the A5.

Additional plus - you can use dual banana plugs with the A5. You just need to wire them up differently. Use one across the positive terminals, and the other across the negative terminals. Of course, that could have been avoided if the output terminals were arranged (+ - / + - ) rather than (+ + / - - ), so I guess that's peeve #4, LOL.

Now, is Douk Audio going to produce a companion subwoofer amplifier to match the A5? Basically, the A5 with an adjustable low-pass filter instead? Or, even better, with adjustable low-pass and high-pass filters .

 

[PC Audio Lover]

Or, even better, with adjustable low-pass and high-pass filters .

That would be awesome to put both in a pre-amp - like the Emotiva pre-amps and integrated amps!

 

[EJ3]

I purchased and received an Douk Audio A5 from Amazon a few days. Nice little amp. The clear acrylic top cover can't be fastened into place (which means I'll have to rig up something - until that happens I've left the peel-off sticker in place),

Perhaps a bit of highly flexible silicone caulk at one end?

I have one & do not see an issue at all (I do not pick it up & play with it, I do not have animals or children at home. Pets were not allowed in the living room, where the stereo is (period).
My child (now 36 & an English Teacher & Soccer Coach) was taught what things to not touch unless there was an adult assisting him (either physically/verbally or both). Just as he knew not to enter any bedroom [aside from his own]) without permission (door open {as they were normally for air circulation} or not.
And today, just like any other visitor, knows not to just "come over".

 

[capslock]

The only measurements I have seen is from the manual.

View attachment 427849

- 88 dB HD2, - 90 dB HD3 and HD5 - while ok, that must really be the worst performing PFFB implementation I have seen. There is this video that has data at 1 W instead of 5 W. While it show even - 88 dB HD3, it is better on HD 2 and 5.

Still, even the Aiyima A70 is better, and that was the worst performing PFFB on my list before I saw the Douk A5.

 

[NovakJi]

- 88 dB HD2, - 90 dB HD3 and HD5 - while ok, that must really be the worst performing PFFB implementation I have seen. There is this video that has data at 1 W instead of 5 W. While it show even - 88 dB HD3, it is better on HD 2 and 5.

Still, even the Aiyima A70 is better, and that was the worst performing PFFB on my list before I saw the Douk A5.

So you are saying the douk a5 is not good? In your opinion which amp has the best pffb implementation so far and also has Bluetooth?