What is your favorite Class D amp?

All of you guys are selectively quoting facts in an attempt to mislead one another.

@devinplombier This statement is false. Facts are never misleading. 

Something that you are not taking into account is the supply Voltage fed to the chip. That determines how much output power is available. 

It doesn't affect distortion so much at full power for the given Voltage.  Do you see how this works?

That is why the specs Jim quoted above are likely to be true despite TI correctly stating its distortion at that power using a greater power supply Voltage. 

If the Voltage sags at full power the amp is also more likely to have higher distortion. That is why a robust supply is so important. 

@atmasphere wrote:

This statement is false. Facts are never misleading. 

...unless you happen to omit half of them. But let’s go back:

@jimbennet wrote:

Why all the $2K amps? The $110 Douk NS-13G sounds as good as rebuilt tube amps having best tubes and coupling capacitors. Amp has phono stage and tone controls. 60 watts per channel.

Much of that statement is legitimately objectionable, but not really the 60wpc claim. Yet for some reason that’s what you chose to focus on: 

@jimbennet If you think it sounds as good or measures as well you’re fooling yourself. Look up the specs on the chip it uses and you’ll see: 10% THD at full power [...] can drive up to 2 x 315 W into 4-Ω load at 10% THD

Yes that’s true, but it’s irrelevant since @jimbennet claimed a mere 60wpc for the Douk amp - not 315wpc.

I think you’ll agree the TPA3255 can deliver 60wpc at less than 1% distortion, let alone 10%.

It would have been better to explain why comparing a garbage $100 amp with well-designed and properly built amps is apples to oranges, starting with, as noted, their respective PSUs’ power-delivering abilities.

Look, I guess what I want to say is that it’s always best to educate when you’re in a position to do so, which I believe you are, rather than shut down people with selectively quoted data from, in this case, the TPA3255 datasheet which, if anything, supports @jimbennet ’s 60wpc claim.

Sharing knowledge benefits everyone, especially on a forum like this one where technical proficiency levels are quite diverse.

I run a Peachtree Gan 400 on my Magnepans, no issues or complaints.

https://doukaudio.com/products/douk-audio-ns-13g-max-hifi-mini-2-channel-stereo-audio-amplifier-class-d-power-amp-with-phono-300w-2

@devinplombier Take a look at the link above.

Only the 5 Watt power distortion is shown. 

The supply is rated 48V @5A. Look at the 4 Ohm power rated with this supply. Its 240V, the same rating as the output of the supply! By that metric the amplifier is 100% efficient. Since that isn't so, its pretty obvious that things aren't going to measure up as claimed. 

What you don't see is the 10A supply for this amp. The stock supply is a 5A unit. As long as you don't push the amp hard it will not make much distortion. Funny thing, the amp uses a chip and isn't GaNFET, but the power supply is marked 'GaNFET Adapter'.

I'd be curious to see how this amp holds up running at full power with the 10A supply. 

IME if you want to make a class D amplifier do its thing, the power supply is vitally important. What we don't know here is what supply was being used when the amp was tested, what load impedance it was driving and so on. 

If the supply has trouble holding up at power (which I have to assume is the case, given the output power figures aren't correct), the distortion will rise. 

But as I said when this first came up, amps like this challenge stuff costing a lot more. I'd be interested in seeing what it does with a proper power supply. 

@atmasphere wrote:

The supply is rated 48V @5A. Look at the 4 Ohm power rated with this supply. It’s 240W, the same rating as the output of the supply! By that metric the amplifier is 100% efficient. Since that isn’t so, its pretty obvious that things aren’t going to measure up as claimed. 

[...] I’d be curious to see how this amp holds up running at full power with the 10A supply. 

Well, according to Douk’s product page, with the 10A power supply the amp makes 250w + 250w @ 4 ohm.

In other words, it takes in 480W but outputs 500W. Magic! 😃

This brings up a great point, namely that manufacturers’ power claims and ratings should be taken with a grain of salt until they’re carefully looked into. You’d expect these kinds of shenanigans from Douk or other entry-level brands out of China, but wannabe high-end manufacturers like NAD play even worse games.

For instance, Bob Carver makes (made?) a very nice-looking tube amp rated 75wpc, but its output transformers were so small there was just no way, and sure enough ASR measured it clipping at something like 17 watts.

You’d think ASR would have reviewed the Douk but sadly they haven’t. That might have shed some light on its real power and THD+N numbers.

But as I said when this first came up, amps like this challenge stuff costing a lot more.

That’s for sure! Though as you’ve stated PSU quality is key, and in that price range a good PSU can easily cost more than the amp it powers.