Topping Mini 300 Amplifier Review

[gvl]

Convincing.

@amirm, thanks for your work. Was there a SnR test?

 

[BeeKay]

The E50 is objectively perfect, so what is there to wait for in a review of MK2 since the odds of it being less than even more objectively perfect is next to none?

PEQ

 

[gvl]

Given we already have balanced inputs, how difficult world it have been to allow bridged mode?

 

[phoenixsong]

Voted great but I already am enjoying the 3e A5 so there's no need for me to get this one. Awesome price though!

 

[phoenixsong]

Voted great but I already am enjoying the 3e A5 so there's no need for me to get this one. Awesome price though!

 

[dark132]

My dear Amir, a single meal in a restaurant costs usually less than 140 $ or €, even in our expensive Paris, except in a chic restaurant and buy a good alcolhic starter and then a good wine, and in the end a nice italian or french style coffee.
Come to Paris, I'll show you good adresses with better prices than this Topping

But as for this little piece of electronics, I definetely agree with you, this cheap little amp's awesome.
I wish for a slightly more expensive model at double power with the same performance.
I won't be surprised if Topping's already working on it to replace their last amp generation.

Chinese people favour family-style gatherings, often involving six to ten individuals, particularly during the New Year period when they dine with relatives. The cost typically ranges from $120 to $150.

 

[CD2]

Thanks for a great review and a really helpful discussion!

If you were going to build an inexpensive, compact system around this, is there a preamp-plus-dac that people would recommend?

 

[OldTimer]

Thanks for a great review and a really helpful discussion!

If you were going to build an inexpensive, compact system around this, is there a preamp-plus-dac that people would recommend?

I’m using it as Pre-Out of my old Integrated Amplifier. I think most people already had AVR, or Stereo Receiver, or Integrated Amplifier.

 

[Power Pop 23]

Thanks for a great review and a really helpful discussion!

If you were going to build an inexpensive, compact system around this, is there a preamp-plus-dac that people would recommend?

Consider a preamp-plus-dac with a 12 volt trigger output to power the Topping Mini 300 up or down.

How much are you comfortable spending ?

 

[CD2]

Consider a preamp-plus-dac with a 12 volt trigger output to power the Topping Mini 300 up or down.

How much are you comfortable spending ?

Thanks! I was wondering whether something like this might be enough: https://www.audiosciencereview.com/...-zh3-balanced-headphone-amp-dac-review.65913/ I'm comfortable spending quite a bit more, but it seems like an open question whether you need to these days.

(I'm ditching an old system and moving internationally to a little flat, so I'm looking to start fresh and start small.)

 

[capslock]

You know how in the headphone and source market we have devices with $2 opamps that are audibly perfect? The equivalent in the amp market seems to be the $6.50 TPA3255/3251 chips that can deliver audibly perfect performance up to ~200 watt.

The key is when Bruno Putzeys figured out how to put a class D output filter inside of the feedback loop and how to increase the order of the feedback loop without driving the amp into instability. The benefit that we are now seeing is that these improvements can be achieved with the addition of a few passive components (capacitors and resistors) and some electrical engineering math. At first this only benefitted Bruno's employers as he had a number of patents from the late 90s and 00s.

Now that the patents are expired and we have five different China-based amp makers (Topping, Fosi, 3E, Douk, Aiyima) competing, it is getting very hard for these chip makers to charge a lot for what in the end of the day is a couple small capacitors and a resistor network. This amp is basically a "PA5 III plus" where Topping is undercutting the price due to increased competition since the PA5's original release date (3e A5, Fosi v3 mono, Duok A5 Pro, etc.)

The class AB 'big iron' amp makers should be hiring electrical engineers to increase the order of the global negative feedback networks in their amps. Class AB amps have enough bandwidth that they should all be able to deliver 120 dB SINADs like the recent Topping LA90/B100/B200. I wonder if the old guard is going to rise to the challenge, fade away, or sell nostalgia and brand by sticking with their existing achitectrures.

Much as I appreciate Bruno and his work, it was about a different kind of Class D amplifiers, i.e. self-oscillating amplifiers that he named UcD. To the best of my knowledge, the TI chips are not UcD. The other secret source is that he uses very high order compensation, allowing him to keep loop gain high throughout most of the audio band resulting in better HF performance. He may even be using a composite design in the newer incarnations.

In contrast, even the better designs with these TI chips are not composites. Datasheet PFFB increases loop gain only by about 6 dB and improves LF (up to 1 kHz) performance at the cost of HF performance. The more sophisticated implementations such as Toppings have a clever gain structure and seem to add at least one pole to the compensation. They beat the lesser NCores (e.g. NC252MP) in LF performance, but not in HF.

As for power consumption, it is true that Class D is more efficient at high output power but considering that in home applications, our amps are rarely putting out more than 1 W, they are not necessarily the most efficient solution.

Both the Hypex SMPS as well as the NCore amps have quite a significant idle draw (the newer NCx may be better, haven't checked). The TI amps are better in this respect.

Now to Class AB, a large conventional, ideally a toroidal transformer beats most SMPS on idle losses. Class AB with optimal bias (as defined by Doug Self) or even below, careful choice of rail voltages, maybe only one transistor pair (I know, not ideal for distortion) can beat a TI chip amp. Distortion can be reduced significantly by two-pole-compensation (no need to use 5th order with AB as the delay is much lower). Composite amps are also much easier to do with AB and can achieve stellar LF and HF distortion performance with minimal bias and single transistor pairs.

 

[Power Pop 23]

Thanks! I was wondering whether something like this might be enough: https://www.audiosciencereview.com/...-zh3-balanced-headphone-amp-dac-review.65913/ I'm comfortable spending quite a bit more, but it seems like an open question whether you need to these days.

(I'm ditching an old system and moving internationally to a little flat, so I'm looking to start fresh and start small.)

Agreed on spending. I think the Fosi Audio ZH3 would work well with the Topping Mini 300.

 

[amirm]

@amirm, thanks for your work. Was there a SnR test?

Oops. Just added to the review:

 

[Tell]

In contrast, even the better designs with these TI chips are not composites. Datasheet PFFB increases loop gain only by about 6 dB and improves LF (up to 1 kHz) performance at the cost of HF performance. The more sophisticated implementations such as Toppings have a clever gain structure and seem to add at least one pole to the compensation. They beat the lesser NCores (e.g. NC252MP) in LF performance, but not in HF.

I don't really understand how amplifiers work on the inside, but I saw this thread on diyAudio a while back about a guy cramming extremely impressive performance from the TPA325x, is it the same that you're talking about here?

 

[capslock]

I don't really understand how amplifiers work on the inside, but I saw this thread on diyAudio a while back about a guy cramming extremely impressive performance from the TPA325x, is it the same that you're talking about here?

That is a composite approach. He roughly describes what he did but not exactly how. That is not what Topping are doing but it can potentially land the TI chip in NCx and Purifi territory.

 

[KL....]

It has almost identical measurements to the PA5 II tested by Amir, but the PA5 II does not go into protection mode at 20Hz.

View attachment 501279
View attachment 501280

Thank you, @daniboun, Yes, similar, although why would you consider these 2 graphs as almost identical measurement?

 

[Tell]

That is a composite approach. He roughly describes what he did but not exactly how. That is not what Topping are doing but it can potentially land the TI chip in NCx and Purifi territory.

Yeah I don't know what a composite in this instance means, all I see that he gets really good performance doing whatever he's doing, and I also see Topping is getting more or less the same with whatever they're doing which is much better than what others (Fosi, Ayima Douk etc) are doing with their regular PFFB designs.

 

[delta76]

It's a great little amp for very little money. What's not to like, if it is reliable too?

The $139 question
Reliability and longevity are yet to be seen. However after 2 years when we have enough data to answer those questions, this will be already EOL

 

[French Meloman]

Careful and very interesting review as always. The main point here is to note that chip amplification is progressing rapidly and allows for very high-performance amplifiers at a low cost. This level of performance was still a dream less than 10 years ago for this type of device.
The fact that Topping has implemented protection in the low frequencies with a reduction in power is certainly a way to make the product more reliable. Furthermore, the 80 W that Amir measured at 40 Hz is certainly sufficient for most use cases.

 

[OldTimer]

The $139 question
Reliability and longevity are yet to be seen. However after 2 years when we have enough data to answer those questions, this will be already EOL

Do you mean “If there is an expensive one, why buy a cheap one?”, is it?