Topping B100 Amplifier Review

[No one who matters]

Love the specs, needs 3-4x power.

 

[ivanj]

Perhaps I overlooked something.
1. How does it measure into a simulated speaker load?
2. Any ideas how they made a class B amp so clean?
Thanks.

 

[NwAvGuy]

Two of my least favorite things in an amplifier combined: monoblock and external PSU
And it barely has enough power to drive some bookshelves. Well, one. Not exactly sure who this product is aimed at.

People here on this forum is of course who is being aimed at.

 

[MZKM]

Hmm, $600 for stereo @ 50W.

I assume this is more intended for desktops using passive speakers (super low noise so no tweeter hiss) or for smaller rooms.

Either way, amazing performance. I’d happily take some middle-ground between this and something like a Crown amp that’s all about wattage.

 

[restorer-john]

The high feedback and low distortion is also not limited to bass and mids but even to the highs.

Topping's measurements. 0.0001% is -120dB.

View attachment 392557

That's with a 20kHz measurement bandwidth. The harmonics are falling off the measurement. Amir is only measuring one harmonic of 20kHz and it's already shooting up. Don't let Topping's AP plots deceive you.

 

[Matias]

Well there is the Topping B200 with similar low distortion and double the power, but it is also double the price...

 

[renaudrenaud]

Well there is the Topping B200 with similar low distortion and double the power, but it is also double the price...

Maybe it doubles your interest?

 

[shuppatsu]

I love Topping for DACs and HPAs but $600 is starting to approach real money and for that price I’d want to get more than 50WPC and a difficult to service amp. The specs are awesome as an engineering exercise but I’d rather have power, peace of mind, and/or money in my pocket.

 

[terryforsythe]

Amir is only measuring one harmonic of 20kHz and it's already shooting up.

To which graph are you referring?

 

[kyuu]

To which graph are you referring?

I believe he is referring to this one:

I'm not sure what he means that a harmonic of 20kHz is shooting up though.

 

[Vince2]

Any idea how this amp behaves with speakers with <4 ohm?

 

[JSmith]

I'm quite stunned at this performance from a Class B design... nice testing @amirm.

inside

JSmith

 

[terryforsythe]

I believe he is referring to this one:

I'm not sure what he means that a harmonic of 20kHz is shooting up though.

It looks good to me. All harmonics below 20kHz look to be -118dB or better. The worst harmonic is around 39kHz, and that still is -109dB. There is no way anyone is going to hear that. Heck, I can't hear anything at 39kHz, let alone something down -109dB.

 

[IPunchCholla]

Two of my least favorite things in an amplifier combined: monoblock and external PSU
And it barely has enough power to drive some bookshelves. Well, one. Not exactly sure who this product is aimed at.

People who want incredible clean amplification for near field speakers?

Or people who have 4 ohm speakers and don’t need it super loud? I mean, even with 86 db @ 1 watt/meter speakers peaks are going to be clean at 105dB @ 1 meter.

Edit to add: These aren’t for me. I have active near fields that I’m happy with, but I can imagine a few use cases I might employ them.

 

[Bruce Morgen]

I love Topping for DACs and HPAs but $600 is starting to approach real money and for that price I’d want to get more than 50WPC and a difficult to service amp. The specs are awesome as an engineering exercise but I’d rather have power, peace of mind, and/or money in my pocket.

It's all about the use case. In my particular 7.1 system, using $1200(!) worth of these instead of less than $100 -- for the pair of four year old Aiyima A07s that run my four ambience/surround channels, the remaining speakers being active -- would very likely result in near-zero audible improvement, despite the B100's clearly stellar specs. For a straight 2-channel or 2.1 system paired with absolutely top-notch, reasonably sensitive passive speakers, a pair of B100s might make some sense -- but, as pointed out elsewhere in this thread, $600 for two sub-100 watt channels of admittedly excellent amplification isn't exactly a price/performance breakthrough in a marketplace that includes ICEPower, Hypex, and Purifi stuff available from trustworthy OEMs, not to mention the fuktonne of proven Class D chip amps that measure nearly as well for a lot less moolah.

 

[Old_School_Brad]

I'm quite stunned at this performance from a Class B design... nice testing @amirm.

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JSmith

That looks strikingly inadequate for cooling BJT or MOSFET with the spec'ed power in a closed case with side vents.
But they did win the numbers race.

This looks to me like there is resistance enough through the connection in the power socket to heat it.

 

[phoenixdogfan]

Great review, Amir. This amp is for someone looking for perfection in a desktop system, I think, and it will surely provide it. Interesting how it's pure Class B, and achieves its performance through generous application of negative feedback. I'm old enough to remember the old audiophile canard from the 1970's that negative feedback was anathema because it introduced "transient intermodulation distortion (TIM)." That was so much the case that a few amplifiers were marketed back then with no negative feedback applied at all. The one that comes immediately to mind was the Mark Levinson ML-2 which was a pure class A design the size of a Krell monoblock which output 25 WPC and sold for a cool $2800 each in 1977, equivalent to $14,500 in 2024 purchasing power, or $29,000 for a pair.

Of course what was not realized at the time was that the solution to TIM in those early transistor designs employing negative feedback was to use even more negative feedback to kill the TIM as well. Now we know better, so much so that Topping can introduce an amp with twice the power of that Levinson and 120 db Sinad levels, while costing only $600 a pair, and being small enough to fit on a desktop. Progress!

 

[Doodski]

I'm quite stunned at this performance from a Class B design... nice testing @amirm.

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JSmith

Looks pretty simple and nice. Lots of OP amp rolling possibilities too. Hehe...

 

[restorer-john]

To which graph are you referring?

This one:

The 10kHz and 15kHz are rising and there's only 2 harmonics for the 15kHz, 3 for the 10kHz. (45kHz measurement BW)

The Topping graph showing THD+N is only showing +N in reality at high frequencies, so it's a bit deceptive.

But none of that takes away from the performance within the range that Amir has tested.

 

[Hayabusa]

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

How is the protection kicking in? Audible artifacts? Just a mute for so many milliseconds? Or does it need to be reset?