Topping B100 Amplifier Review

[Roland68]

Are monoblocks a fad?

Yes, this fad started when AVM introduced their first monoblock amplifier in '88/89 for an affordable pair price of around DM 1400 / € 700 and also published the circuit diagrams for DIYers. Since then, mono power amplifiers have been introduced more and more often that are in an affordable range.
The AVM Mx mono power amplifiers were and are so good that they are still hyped by many users today and the selling prices are often higher than the original price at the time.

The expensive ones were always the power supplies with heavy transformers and high-quality capacitors with high filter capacities. Switching power supplies are cheaper and more compact.

 

[Mnyb]

I have nothing against external PSU per see , but these plastic laptop power bricks ? Cooling simply can’t be great if it’s enclosed in an airtight plastic box ? If you build a better ventilated metal enclosure for the PSU you migth as well put it in the amp and save one box ?

Yes it’s easy to replace as you probably also need to , these things longevity are dubious.
Just like the old joke why some English houses have the plumbing on the outside, it’s easy to repair when it freezes

PSU and amp can be designed with the same longevity and service friendly design . Certification should be a normal thing to do for a serious manufacturer. I do see a problem when you have a very frantic product cycle if the product’s intended lifecycle is shorter than the time it takes for proper certifications , then I get the pre certified PSU ?

 

[ryanmh1]

In the old texts about audio amplifier design, it was often stated that negative feedback cannot smooth out the crossover notch in the output waveform caused by class B operation, because there is no gain with both push-pull output devices in cutoff, so there can be no negative feedback. I'm sure the Topping engineers have done something to get past this limitation, but I wonder exactly what. Whatever it is, it can't be as simple as just slapping as much negative feedback around the circuit as it can stand before oscillating.

Or, option 2. The amp is AB, but without much bias current. There's no reason to assume Topping broke the mold here. The distortion levels are low, but nothing that DIYers haven't been doing for years. There's no reason to believe they've done much more than put a derivation of one of those established DIY designs into a box and sell it. That's not to diminish the achievement, since no one else has bothered to do it. Amps with these distortion levels have existed for years. You just had no way of buying one assembled, which was absolutely maddening and ridiculous

 

[staticV3]

The protection circuit is aggressive with 4 ohm load, not allowing the amplifier to go into clipping:

More power can be extracted by using finer steps in the input sweep voltage prior to protection circuit shutting down. So I suspect with out playing around you may be able to get there.

To give more context, I traced Amir's power sweep and it looks like the APx was set to ~0.62dB step size:


85.53W was clean and one step higher triggered protection, ergo 85.53*10^(0.62/10)=98.65W

Not quite the full 100W, but within margin of error I'd say.

 

[somebodyelse]

all change in january 2025 : 0,3 max

Where does it say that? No sign of 0.3 in that link. Are you thinking of 2027 in 'off' mode? From the earlier link:

• from 2025, devices must not consume more than 0.5 Watts in standby or in off mode, or 0.8 Watt if they are on standby while displaying their status or information
• from 2027, devices must not consume more than 0.5 Watts in standby, 0.3 Watts in off mode, or 0.8 Watts if they are on standby while displaying their status or information
• From 2027, devices in networked standby must not consume more than 2 to 7 Watts depending on the product

 

[YSC]

Never questioned their SINAD, but for topping amps I am more inclined to watch for internal layout or thermal solutions. The chassis temp don’t mean much, it can be some really insulating materials like potting materials hindering heat transfer so that it can be 43C in chassis and 75 internally

 

[Sokel]

Where does it say that? No sign of 0.3 in that link. Are you thinking of 2027 in 'off' mode? From the earlier link:

There are thoughts about tighter limits already so the 2027 can be revised.
Till then is as you posted.

Had a look at the PSU (I believe is this one) and it seems certified for both US and EU so it should be ok following the regulations.
Now,combined with the amp,only a precision measurement can tell us if it's legal or not for EU as a whole.

 

[Roland68]

I have nothing against external PSU per see , but these plastic laptop power bricks ? Cooling simply can’t be great if it’s enclosed in an airtight plastic box ? If you build a better ventilated metal enclosure for the PSU you migth as well put it in the amp and save one box ?

Yes it’s easy to replace as you probably also need to , these things longevity are dubious.
Just like the old joke why some English houses have the plumbing on the outside, it’s easy to repair when it freezes

PSU and amp can be designed with the same longevity and service friendly design . Certification should be a normal thing to do for a serious manufacturer. I do see a problem when you have a very frantic product cycle if the product’s intended lifecycle is shorter than the time it takes for proper certifications , then I get the pre certified PSU ?

HP and other companies have been using such power supplies for workstation notebooks with much higher performance (230 watts and higher) for 20 years, without any problems. Defects are very rare and these power supplies are usually retired after 7-10 years with the notebooks. And we are talking about at least 8-10h/5d use, often even more.
So it is neither new nor untested.

In addition, such power supplies have an efficiency of around 94%, so that only a single-digit wattage of waste heat can be generated. In addition, the power supply of the B100 is well oversized so that it does not heat up much during operation.

The power supply is also used in the PA5/II (38v/3.2 or 4A), where it is subjected to a higher load and in my case, at high continuous power, it only gets hand-warm, no more.
Attached is a picture of the 3.2A power supply of the PA5 II, well built, components are OK and there is enough aluminum for cooling. If such a power supply only gets hand-warm even under heavy load in continuous operation, why shouldn't the plastic housing be sufficient?

 

[Cogito]

I would have given it a "Great" rating had the power supply been built in. I can't stand external power supplies despite any advantage they might have. Just more cable clutter.

 

[EJ3]

Maybe what not where?

What ever location you are in. They must be able to sell it somewhere or they wouldn't be making it like that.

 

[Sir Sanders Zingmore]

The benchmark system I am using is already good. I cannot imagine how good this Topping amp would sound.

I can. I imagine it would probably sound exactly the same.

 

[Colonel7]

It’s an another topping sinadifier made for Yogi Berra. “ It’s so quiet it doesn’t make any noise!” Kind of like a dishwasher that is so quiet it doesn’t wash dishes

 

[totti1965]

We're talking about a basic design element of this particular 'class B' amp reviewed here. I think that's 100% reasonable.
Or is this a subjective review?

No, the topping B100 is Class AB! @amirm just didn’t correct it.

 

[Sokel]

No, the topping B100 is Class AB! @amirm just didn’t correct it.

Topping says is class B.
Some sellers advertise it as class AB.
There's no mention in the spec's sheet.

All they describe about the circuit is:

T'ang-ku-la Module
The creation of T'ang-ku-la module shows our determination to pursue excellence and constantly challenge the physical limits of performance.


The T'ang-ku-la Module uses a brand new three-stage feedback circuit technology. It reduces circuit noise and high-frequency distortion, thereby increasing the dynamic range of the power amplifier to 151 dB. This technology also significantly lowers the heat produced by circuits, further boosting the reliability of the circuits, extending service life, and effectively diminishing thermal noise.

I'm inclined to believe Topping.

 

[AnalogSteph]

I have nothing against external PSU per see , but these plastic laptop power bricks ? Cooling simply can’t be great if it’s enclosed in an airtight plastic box ? If you build a better ventilated metal enclosure for the PSU you migth as well put it in the amp and save one box ?

The cost / effort for certification alone is nothing to sneeze at, and is something you may want to avoid on a product without insane margins and a limited production run. An OEM also is likely to have a proven design already, while rolling your own is always fraught with some risks. (I still have a Fujitsu Esprimo Q910 USFF PC floating around with a dead internal power supply which blew a MOSFET after merely being unplugged for 10 minutes. These are kind of notorious for that; since all it does is generating a 20 V rail some people will mod them to accept an external laptop brick instead. Otherwise the thing seems very neatly engineered.) If this is the same supply already used for another model, all the better.

 

[Mnyb]

The cost / effort for certification alone is nothing to sneeze at, and is something you may want to avoid on a product without insane margins and a limited production run. An OEM also is likely to have a proven design already, while rolling your own is always fraught with some risks. (I still have a Fujitsu Esprimo Q910 USFF PC floating around with a dead internal power supply which blew a MOSFET after merely being unplugged for 10 minutes. These are kind of notorious for that; since all it does is generating a 20 V rail some people will mod them to accept an external laptop brick instead. Otherwise the thing seems very neatly engineered.) If this is the same supply already used for another model, all the better.

You can have an OEM internal supply too , like my Meridian equipment did , and ofcourse they broke and had to be replaced
But anyway that’s also a way to do it , no need to develop a switch mode supply yourself they are of the shelf if you want .

 

[NTK]

You can have an OEM internal supply too , like my Meridian equipment did , and ofcourse they broke and had to be replaced
But anyway that’s also a way to do it , no need to develop a switch mode supply yourself they are of the shelf if you want .

Me think a reason for external power bricks is to circumvent the requirement to conform to the Low Voltage Directive for the purpose of CE mark. The Low Voltage Directive applies only to devices that use AC between 50 -1000 V or DC between 75 - 1500 V.

Low Voltage Directive - Wikipedia

en.wikipedia.org

 

[renaudrenaud]

What does it mean? It means 450€ for a pair of awful equipment.

I summarize:
- not enough power (I use 98dB speakers in a small room)
- stupid power brick (easy to change in case of failure)
- no LED string in the front (I must admit it is a big failure)
- stellar performance you don't care because 80dB sinad is enough.

Ok, too late to order right now, but tomorrow is another day.

 

[Roland68]

The thing is that you can't connect a $10k audiophile power cable to it, right?

You can buy power cables with C7 connectors for several hundred or several thousand €/$, no problem.
But you can also spend a few euros/$, less than 10, on good material and get something like this.

The only thing I would improve here is the directions from which the cables come out of these bricks, cable management would be much easier if the output and input were on the same side...

For me it would be worse, but that will be different for everyone. Entrance and exit on opposite sides is simply "form follows function".

 

[somebodyelse]

What ever location you are in. They must be able to sell it somewhere or they wouldn't be making it like that.

Audiophonics is a retailer in France, offering the B100 to customers in Europe. They need to follow EU legislation.
https://www.audiophonics.fr/en/power-amplifiers/topping-b100-silver-p-19764.html

I don't mean to single out Topping here - we've seen other manufacturers with reported standby consumption >0.5W like the Schiit Vidar 2, Fosi V3 Mono (in auto-sleep), Soncoz SGD1.