Topping B100 Amplifier Review

[MabeHall]

Reserved for @AdamG to kindly post the specs.

Manufacturer Specifications:

View attachment 392556

Please ignore my ignorance, but since I was thinking of getting a mono block with this type of connections, I have a question. I'm not familiar with this type of connection. From what I have found, the DAC or preamp XLR end would be a female and I think I get that, but the amp connection looks like a keyed TRS connection. I haven't found anything keyed like that and....is the amp connection a mini-TRS or 1/4 inch or......?

 

[somebodyelse]

Please ignore my ignorance, but since I was thinking of getting a mono block with this type of connections, I have a question. I'm not familiar with this type of connection. From what I have found, the DAC or preamp XLR end would be a female and I think I get that, but the amp connection looks like a keyed TRS connection. I haven't found anything keyed like that and....is the amp connection a mini-TRS or 1/4 inch or......?

The balanced input socket is a combined connector that will accept either 1/4" TRS or XLR. You can use whichever you prefer.

 

[rongon]

My speculation is that they designed a circuit that performs like a class A/B amplifier, but without the biasing diodes, hence calling it class B.

How you get the bias voltage is not the difference between class AB and class B operation. I posted a graphic showing what class B operation is, earlier in this thread.

 

[rongon]

Totally incorrect.

Also, putting aside the position of power supply within an amplifier architecture, so many tests have been done on power supply interactions (or lack thereof), including replacing Linear PS with SMPS.

The power supply is about the lowest thing on my list of important amplifier features.

It's unfortunate that after page 2 or 3 of these ASR reviews, all sorts of speculation and misinformation on the review subject flourishes.

I don't agree, and it's not any kind of "speculation".

The basic architecture of any amplifier is based on the power supply being modulated by the amplified signal. That's why power supply impedance is important. It is a solved problem in general, but it is a problem to be dealt with in the design.

An example:
You can ruin a perfectly good amplifier by powering it from a noisy, high output impedance power supply. Why would that be?

I agree that swapping a perfectly good SMPS with a perfectly good linear power supply will do pretty much nothing. But that does not prove that power supply interactions with audio amplifier circuits don't exist.

 

[MAB]

I don't agree, and it's not any kind of "speculation".

Not sure what you don't agree with. Firstly, your comment "The power supply is 100% in the signal path in almost all audio amplifier designs" is completely wrong at all levels.

The basic architecture of any amplifier is based on the power supply being modulated by the amplified signal. That's why power supply impedance is important. It is a solved problem in general, but it is a problem to be dealt with in the design.

Now you are saying something different. You are now alluding to different things.

An example:
You can ruin a perfectly good amplifier by powering it from a noisy, high output impedance power supply. Why would that be?

OK, please show. Without an actual example, this is an anecdote.

I agree that swapping a perfectly good SMPS with a perfectly good linear power supply will do pretty much nothing. But that does not prove that power supply interactions with audio amplifier circuits don't exist.

Again, please show.

 

[pma]

There seems to be a circuit misunderstanding. Power supply output impedance is not equivalent to amplifier output impedance. An amplifier with high feedback factor may have very low output impedance even if its power supply has output impedance in units of Ohms. The result of higher power supply impedance is decreased maximum output power of the amplifier.

 

[shuppatsu]

Totally agreed on your comments about power supply quality and cost. The power supply is 100% in the signal path in almost all audio amplifier designs, so for elite performance you want a bulletproof, quiet and preferably over-spec'd PSU. That inevitably costs more money. SMPS are getting better all the time, though. But there is that switching frequency issue to filter out -- and the filter costs extra money too.

We have elite performance with SMPS right here. Whatever problems there might have been have been solved with engineering, and have been for a long time.

 

[Mnyb]

We have elite performance with SMPS right here. Whatever problems there might have been have been solved with engineering, and have been for a long time.

No problem with smps per see , I don’t think I own anything with a so called linear supply anymore ? Benchmark did the rigth thing to use it thier amp .

Even if I’m critical to an external power brick, it’s a minor thing for me , if I were in the market for a 50 wpc small amp this thing is one of the contenders. I’ll would just have to hide the clumsy ugly bricks somewhere out of sight.
I gave it the second highest praise ffs so it’s not the end of the world.

 

[Mnyb]

And good circuits have very good so called psrr ( power supply rejection ratio ) they are not to bothered by dodgy power supplies re performance until they sag . Going out on a limb here I think this also is due to proper feedback ? Educate here if I’m wrong

More myth driven brands who loathe negative feedback etc , actually makes this a self fulfilling prophecy their outdated designs can be more sensitive to power supply problems ?

Sometimes I think audiophiles are truly ignorant and make cargo cults of everything technical in the hobby .

Class A is the best it must be it begins with an A .
Negative feedback cant be Good its negative you know .
Class D is digital, thats obvious due to the D

 

[Sokel]

Where is it written that the "seller" cannot sell a product that has higher consumption?

Here:

Link also posted here.

It refers to both manufacturers and suppliers.
Of course an importer/supplier of thousands of products like Audiophonics may not know and there comes the good faith between them and the manufacturer.
Nevertheless,by law,they must know.

 

[ryanmh1]

Please share a link to that amp but only if it is as distortion free and clean above 1Khz as this one is.

I said "similarly powered and similarly transparent." That means to the human ear, if that wasn't clear. I never said "as distortion free and clean". For "similarly transparent" literally just pick an amp that costs $250 and isn't load dependent and keeps it under, oh, -70dB (.03%) or so. You won't ABx it on "normal" speakers that don't show off the noise floor. Not that there won't be more distortion. There will be. But it's the difference between identically cut and colored cubic zirconia, crystal, and diamond rings from 5 feet. Virtually none.

EDIT: I don't mean to imply you can hear over .03% distortion. That's just so low that it's basically guaranteed at that point. Most people will be stumped an order of magnitude above even that. The "problem" with amplifiers, if there is one, is not measurable harmonic distortion. The crazy low levels here are just an umbrella policy on top of an umbrella policy on top of gold plated insurance. Nice to have, probably don't need it.

 

[amirm]

In that case the measurement needs qualification with an error bound, or removing entirely as misleading. I suppose it may depend on input voltage too.

Or.... don't use it to claim regulatory compliance or not. That was not the purpose of providing the data.

 

[amirm]

@amirm - Is that mention of class B operation a typo? Or did that information come directly from Topping?

It was in email to me from them. But now maybe that was a typo although I don't think so.

 

[yys310]

That's even stranger!

I don't know what to make of this.

Maybe it's a marketing strategy. Calling it class B would generate a lot of buzz, but calling it class AB would not differentiate it from the crowd of other class AB amplifiers. But I really don't know.

Topping Facebook

 

[MAB]

So funny, it's Class AB until it's Class B.

 

[Vigovsky]

PURIFI 1ET400A 4Ω THD+N 1kHz 100W = 0.00015%
TOPPING B100 4Ω THD+N 1kHz 100W ≈ 1%

PURIFI 1ET400A 4Ω 20Hz-20kHz THD+N 100W = 0.00017% !

 

[jcheavymetal]

From another thread here, regarding the amplification class

 

[welwynnick]

PURIFI 1ET400A 4Ω THD+N 1kHz 100W = 0.00015%
TOPPING B100 4Ω THD+N 1kHz 100W ≈ 1%

PURIFI 1ET400A 4Ω 20Hz-20kHz THD+N 100W = 0.00017% !

The Purifi will also be at 1% when the distortion reaches 1%.

What's the point?

 

[Vigovsky]

PURIFI 1ET400A 4Ω, 1%THD+N = 425 W

 

[shuppatsu]

[I was going to add this as an edit to another post, but I think it deserves it's own post.] I'm going to expand a bit on an earlier thought about why we have not seen a lot of amplifiers like this, despite knowledge of how to achieve this performance level being public domain for decades. There is a potentially significant issue for manufacturers, and that is the "commoditization" problem, the death of their entire industry, and ruin of a significant part of this hobby--amplifiers.

DACs were ruined once when the jitter problem was solved in the early 2000s, came back due to streaming, but are essentially ruined again. There is hardly any point in designing or selling one for more than $100 since for $100 you can get something that measures almost perfectly six ways from Sunday in dynamic tests, static tests, you name it. Not everyone realizes it yet, but they will soon enough. As an audiophile item, DACs are living on borrowed time.

Amplifiers have avoided dying as an audiophile product. But what if, 30 years ago, manufacturers started selling straight wires with gain (which they all could have)? With very little fanfare, one of these things actually was designed and stuffed into a PA amplifier in about 1996. Well under .01% THD at any frequency at any power level up to 500W. And I think it cost about $900. That's basically "solved". No one followed. Why not? Partially, fear of the 80s, where amps were "solved" but really weren't since the measurements weren't good enough (i.e. they were not measuring the right thing). But more importantly, if everyone follows, and everything measures below any possible level of audible consequence, the amplifier becomes little more than a blender or a box fan, and they've all gone and put themselves out of business. Benchmark repeated the low distortion performance and added a switching supply to get the noise out, and once again, no one followed. It took decades for Krell or any "boutique" manufacturer to do this (edit: forgot Halcro and Boulder ... which no one followed, again), but they finally are. Linn, Krell, and EMM Labs amps all recently measured by Stereophile show distortion levels from 20Hz to 20kHz that aren't ridiculously bad (read: 1978 levels). 20Hz to 20kHz flat lines below .01%. Very little of any likely audible consequence in any of them. How long can they all sell the same product? What if they all really did sound different before because they were all purposefully imperfect? And now Topping is selling perfection, outside of power levels, for $300. But, the B200 solves some of the power issues for $600. I suspect with a stereo chassis they could solve all of them for about $2000.

What if, say, perhaps not Topping but Parasound, Rotel, or NAD break their adherence to decades old designs and go and sell a 400wpc amp for $2500? Hypex couldn't do it with Class D (so far) since the problems (as they've admitted) are more difficult to solve there, and the elusive "flat line from 20Hz to 20kHz" is more difficult to achieve. But they're getting there. But this thing is just straight lines. No sane person could claim there is anything measured even possibly of consequence. It's a wire with gain. Now, I'll never put it past many audiophile to come up with wild levels of faith and superstition, but at some point, the jig is up. The subjectivists and objectivists have always had at least some deviations in the measurements to fall back on--"well, I can hear that" (you can't, but whatever). But if you throw every measurement in the book at something and it never does anything except perfectly amplify what you stuck in the input jacks, they've gone and screwed themselves. You can't improve or innovate on perfect. I mean, what can Topping do to follow up on this short of adding more power or meters or some other triviality? Nothing. They can sell one to everyone who wants one, and so long as it doesn't break, that's it.

This is not just a potential end game amplifier for some, but if this performance level were adopted industry-wide, it could the end of the whole game. Will the industry ever do it, and cause the death of the hero amp? We'll see.

I don't think DACs have died as an audiophile product and I don't think amplifiers will either. I think there's probably more external DACs being used right now than just about any time in history.

The objectivists are definitely on the upswing compared to the days of Peter Aczel's The Audio Critic often seeming like a lone voice crying out in the wilderness. But subjectivism will never be truly stamped out. People will always want fancy things made in ways that can't be easily commodified. And people will always hear differences outside of extremely difficult to reproduce blinded circumstances.