Topping B200 Monoblock Amplifier Review

[amirm]

I find it a interesting mix of in once sense over engineered and in anther possibly under engineered or some would argue well engineered as it fit for application withing stated limits .

They are trying to break the laws of physics. To get the lowest distortion and noise, they are going the traditional route instead of class D. But then are obligating themselves to stay in the desktop form factor (due to shipping costs, etc.). Within these confines, to produce 200 watts is excellent.

 

[Thomas Savage]

They are trying to break the laws of physics. To get the lowest distortion and noise, they are going the traditional route instead of class D. But then are obligating themselves to stay in the desktop form factor (due to shipping costs, etc.). Within these confines, to produce 200 watts is excellent.

Yes , I see that but it's like making a road car go 250 MPH ( the SINAD etc ) then limiting it to 70MPH ( our ear and brain mechanism, audible thresholds) , can be done just about .. lots of associated expense , lots of increasing complexity in all kinda ways .. no actual real world benefit. As a intellectual pursuit, admirable of course, remarkable even.

imo we've made a fetish out of SINAD , not a criticism at all , it's a force for good overall, least we fall victim as denis says to making perfection the enemy of good.

Now by rites I have to suspend myself as iv used a car analogy, ah don't seem to have the power

 

[Sokel]

But then are obligating themselves to stay in the desktop form factor (due to shipping costs, etc.). Within these confines, to produce 200 watts is excellent.

I used to think like that too.
But then we see stuff like this Tonewinner which is full size, 18 Kg for comparable price (not nice specs I suspect though) .

Should be doable to go full size.
I would put the difficulties more on the certification side, safety standards, etc.
The above is a good hit on price for western gear.

 

[Blumlein 88]

Maybe it is more like making a car that can go 250 mph, but has very limited road holding ability. Or maybe more on point, it is like making a car that has fantastic road holding ability. One useful on the street with the ability to pull 2 gee in turns, acceleration and braking. Yet it only has enough power to go a maximum of 100 mph. Think the amp equivalent of a super Miata. That is not a product with no actual real world benefit, but it is an unusual mix of benefits.

 

[Old_School_Brad]

Maybe if you could bridge a pair then the current would be ample and all the other issues go away in regard to power.

I think we are spoiled by how good amps are now.

Perhaps.

I believe amplifiers have been performing well beyond distortion and noise thresholds for many decades, so it might be useful to broaden the focus beyond just SINAD and be critical regarding other key amplifier parameters. Distortion shouldn’t be used as a reason to overlook other important factors. At times, it feels like this is happening.

This is a power amplifier.
Its main function is to amplify and deliver power to a variety of loads without distorting the signal. We've certainly mastered the "signal distortion" aspect. However, I can't help but feel that this product, like others, is essentially a demonstration of low distortion and noise.

 

[Frank Dernie]

I find it a interesting mix of in once sense the over engineered and in anther possibly the under engineered or some would argue well engineered as it fit for application within stated limits .

So Topping have from a purely functional pov over engineered the SINAD etc but to the detriment of ultimate power delivery and then there's the external PSU , is that good engineering?

So is it a well engineered product ? @Frank Dernie , what do think ?

It seems a strange mix of engineering ideals to me. I can't make up my mind on that but for a matching speaker I would consider this .

It has clearly met its design brief well, so in that sense is well engineered but, personally, I would not buy one.

 

[amirm]

Yes , I see that but it's like making a road car go 250 MPH ( the SINAD etc ) then limiting it to 70MPH ( our ear and brain mechanism, audible thresholds) , can be done just about .

It is a perfect amp up to its max power capability. My Van has a limit of 70 mph although seems to go 80. At that limit, you are holding to dear life so there is no need for it to go faster. Other cars and vans can go faster but ours has two beds and a bathroom.

 

[Thomas Savage]

It has clearly met its design brief well, so in that sense is well engineered but, personally, I would not buy one.

Sometimes you gotta just swim with your briefs , I was a forgetful young school boy so part of me can relate to that.

 

[Scytales]

Why don't you make one? You will quickly realize it is not easy to build such a load that can handle hundreds of watts, and be ultra low distortion. I have built the same dummy load stereophile uses which is only good for very low power and for frequency response testing, not distortion. Point me to anyone doing this kind of testing..

The Germans at Stereoplay/Audio (now at the Testlab laboratory) have been doing that for many decades.

Here is an old article where you can see a dummy load they had used (page 8 of the slideshow that illustrated the article) : https://www.burosch.de/en/audio/1022-klangqualitaet-ist-jetzt-messbar.html

Current set-up in an article written in English : https://static1.squarespace.com/static/5864d96703596e675552b72c/t/58c8f03e03596e8c8dd7957a/1489563712942/Verstärker+Audio.pdf

They say they can measure amplifier up to 3,200 W.

 

[wwenze]

There, hope all groups have been represented.

 

[Melba59]

Doing a theoretical exercise. Assume 5% PSU losses. Assume 70% classAB efficiency. Let’s see where this takes us: 240*0.95*0.7 brings is to about 160W.

I wonder if a 64V 5A PSU brick is used, will it be able to reach the claimed 200W power output, or will it’s design still throttle the power back to the measured 150W++. Hmm…

70% efficiency for a basic class AB design with a linear power supply. The advantage of linear power supplies lies in their EMI cleanliness but not in the efficiency which offers a constraint not the least, their obligation to oversize them. This oversizing has limits because it induces another factor of increase in noise induced by the quality of the more resistant components.

The advantage of the SMPS is its high efficiency, and its peak response in correlation to its The disadvantage: the large number of harmonics generated by the switching process. Due to the high frequency and the complex spectrum, it is not easy to filter them.
By using a more powerful SMPS, the harmonics will increase in power at different frequencies.

This remains to be confirmed, we do not have the schematics: I think that the Topping LA90, LA90D and B200 certainly have a programmable input processor to cancel these harmonics. Using a more powerful SMPS would probably require updating this firmware via the USB-C stamped "FW". Which may not be enough to obtain such good filtering efficiency.

This programmable processor may have a more advanced function than a simple harmonic cancellation function.

I can't find the information, but if these topping amps use power DMOS transistors operating in class AB, it would be a kind of proprietary BASH amp with a similar operation to class D.

The advantage of operating DMOS in class AB lies in the reduction of electromagnetic interference and inerrant distortion to the switching of class D.

These types of amps optimize efficiency, by continuously adjusting the supply voltage according to the amplitude of the amplified audio signal, a constant voltage drop is obtained at the terminals of the output transistors, independently of the output amplitude.

Since there would be no more switching at the output, there remains an impedance adaptation, less influential than with a basic class AB because of the adjustments of the amplified audio signal.

However, these adjustments are limited to the maximum possible voltage drop at the terminals of the output transistors. And that the limitation to 153W in 8Ohms of the B200 is induced by other factors than those of the AB class.

I think that this limitation varies according to the input audio signal and the capacities of the input stage:
- OPA on D90,
- discrete on LA90D in pushpull configured in bridged mode.
- discrete on B200 but in mono, so no bridging of the input stages is possible.

The pushpull being a symmetrical assembly (- 0 +) which allows to double the power and improve the SNR.

The use of OPA for the XLR inputs does not allow to use the OPA of the L & R channels for the bridged ones.
On the other hand, it is probably possible in discrete:

See the quadrupled power on the L90D with the same 240W power supply :

If these toppings do indeed use DMOS transistors in class AB, I think that the limitation of the B200 to 153W/8Ohms is not induced by the power supply but by the simple fact that it only has a discrete mono input stage.

 

[amirm]

Current set-up in an article written in English : https://static1.squarespace.com/static/5864d96703596e675552b72c/t/58c8f03e03596e8c8dd7957a/1489563712942/Verstärker+Audio.pdf

That's the same load I used to produce the reactive load powers in this very review!

 

[boxerfan88]

70% efficiency for a basic class AB design with a linear power supply. The advantage of linear power supplies lies in their EMI cleanliness but not in the efficiency which offers a constraint not the least, their obligation to oversize them. This oversizing has limits because it induces another factor of increase in noise induced by the quality of the more resistant components.

The advantage of the SMPS is its high efficiency, and its peak response in correlation to its The disadvantage: the large number of harmonics generated by the switching process. Due to the high frequency and the complex spectrum, it is not easy to filter them.
By using a more powerful SMPS, the harmonics will increase in power at different frequencies.

This remains to be confirmed, we do not have the schematics: I think that the Topping LA90, LA90D and B200 certainly have a programmable input processor to cancel these harmonics. Using a more powerful SMPS would probably require updating this firmware via the USB-C stamped "FW". Which may not be enough to obtain such good filtering efficiency.

This programmable processor may have a more advanced function than a simple harmonic cancellation function.

I can't find the information, but if these topping amps use power DMOS transistors operating in class AB, it would be a kind of proprietary BASH amp with a similar operation to class D.

The advantage of operating DMOS in class AB lies in the reduction of electromagnetic interference and inerrant distortion to the switching of class D.

These types of amps optimize efficiency, by continuously adjusting the supply voltage according to the amplitude of the amplified audio signal, a constant voltage drop is obtained at the terminals of the output transistors, independently of the output amplitude.

Since there would be no more switching at the output, there remains an impedance adaptation, less influential than with a basic class AB because of the adjustments of the amplified audio signal.

However, these adjustments are limited to the maximum possible voltage drop at the terminals of the output transistors. And that the limitation to 153W in 8Ohms of the B200 is induced by other factors than those of the AB class.

I think that this limitation varies according to the input audio signal and the capacities of the input stage:
- OPA on D90,
- discrete on LA90D in pushpull configured in bridged mode.
- discrete on B200 but in mono, so no bridging of the input stages is possible.

The pushpull being a symmetrical assembly (- 0 +) which allows to double the power and improve the SNR.

The use of OPA for the XLR inputs does not allow to use the OPA of the L & R channels for the bridged ones.
On the other hand, it is probably possible in discrete:

See the quadrupled power on the L90D

If these toppings do indeed use DMOS transistors in class AB, I think that the limitation of the B200 to 153W/8Ohms is not induced by the power supply but by the simple fact that it only has a discrete mono input stage.

Thank you for your insightful post. I appreciate it!

 

[WeekendWarrior]

The power supply from the LA90D is/was 64v, 4amps. I think in one of the other threads on the B200 it was assumed that it's the same PS here labelled differently for some unknown reason, and from Topping's point of view, why would they create another PS?

Anyway, how loud do you guys listen? I've got the LA90D and chicken out before the amp does.

 

[misterdog]

Despite all the worry and concern about the theoretical this and that, they still sound great through my Quad Electrostatics.

The Quad ESL's were designed to be the lowest distortion loudspeakers, so I'm happy to pair them with the lowest distortion equipment available.

Anyone wish to buy my Benchmark AHB 2?

 

[Scytales]

That's the same load I used to produce the reactive load powers in this very review!

Here is someone who gives himself the means to achieve his ambitions!

Peter Schüller used to use that load to make an interesting experiment : he has programmed his Audio Precision to plot the magnitude of some harmonics of the fundamental signal against the frequency of the fundamental and he has run the test on power amplifiers with various resistive and reactive loads (as well as some real loudspeakers used as amplifier loads).

Some results and comments translated in English can be seen on the pdf version of the German article I referred to, pages 31 to 40 : https://www.burosch.de/images/Schueller-lecture-03.pdf

Note : Beware they are some errors of translation from German to English in this document!

I do not claim that this results has any significance at this stage. Nevertheless, I find this kind of experiment potentially enlightening. I do not remember having seen something similar elsewhere. More data gathering would be useful.

 

[BeeKay]

Another report from the living room rather than from the ivory towers. Fairly loud listening over 2hrs 27w measured by the smart socket (per B200). The amps are cool to the touch. Even the A70 Pro and D70 Pro Sabre got a bit warmer in comparison.

 

[Melba59]

The power supply from the LA90D is/was 64v, 4amps. I think in one of the other threads on the B200 it was assumed that it's the same PS here labelled differently for some unknown reason, and from Topping's point of view, why would they create another PS?

Anyway, how loud do you guys listen? I've got the LA90D and chicken out before the amp does.

Topping B200 Monoblock Amplifier Review

Well maybe on the speaker output.... and its a Switch mode power supply. So there are Switches but i don't think this is what is meant. Standby to be precise

www.audiosciencereview.com

This power supply is certainly manufactured by a subcontractor. These power supplies are not specifically intended for audio applications.
Usually, manufacturers give as specifications the maximum amperage that the power supply can support and the voltage measured at no load (maximum when the power supply is not in its limits). This is useful information for electronics designers. For the end user, only useful to replace a power supply that is out of order.

Which explains 64v-4A on the label when in reality from 3.75A consumed, the power supply is no longer capable of maintaining a regulated voltage of 64V within the tolerances for topping or the international market. Topping knows this since in the specifications of the manuals, the power supply was given at 64V and 3.75A = 240V*A or Watts

On this type of power supply, when the voltage is adjustable, the maximum acceptable amperage is indicated (that of the smallest acceptable voltage). In reality, by setting these power supplies to their maximum output voltage, the tolerable amperage drops. Example a 15W, 3A power supply adjustable in voltage from 5 to 15V: set to 15V, 1A max will be sustainable (15W/15V). Set to 5V, 3A max will be sustainable (15W/5V).

This update of the label is rather positive for the end user who would like to replace the power supply with a more qualitative power supply. Not more powerful if it is a SMPS (switching) for the reasons deduced in my previous message #711, these remain hypotheses, for me more and more convincing, but to be questioned.

 

[tomchris]

Wow, impressed with the release of the B200s. Topping raises the bar once again in terms of THD, SNR and Dynamic Range. World Class performance.

However, Topping's choice of design and layout is - as usual - underwhelming, but the performance cannot be faulted. It is what it is.

If you are looking for high output current capability which necessitates power supplies in the kVA range and plenty of capacitance, this is not it.

In any case, I am glad to see the envelope being pushed, especially at this price point.

 

[amarsicola]

My Wiim Ultra feeds a Topping D90 III Discrete via USB. That in turn is hooked up to my B200s via XLR. They run my Revel F206 mains quite nicely. I also have an SVS SB-3000 sub hooked up via the WiiM's sub out.

Interesting setup! Do you manage the volume through the wiim?