Topping B100 Amplifier Review

[mlsstl]

Most musicians wear IEMs, which already have protection integrated.

Pity that Beethoven didn't get the message in time....

 

[Purité Audio]

Beethoven had Jecklin Floats.
Keith

 

[Colonel7]

Add EQ/room correction

This! DSP requires amplification. Power takes priority over SINAD

 

[Thomas_A]

Late response but since this is class B or AB. What’s the short-term output at 1% THD? @amirm was it measured?

 

[amix]

Not exactly sure who this product is aimed at.

The Internet.

 

[eddantes]

50 watts is a LOT unless you have ridicilously inefficient speakers.

Relatively inefficient speakers: 83db@1M@1W > 100db@1M@50W

In my home - 86db is plenty loud for me, and I usually listen at about 2M > that means I'd have 14db of headroom or dynamic range. Todays music ranges between 7-15db of DR.

Thus, I can conclude, that in most cases - I can be certain that I will hear all I need to hear using a 50W amp without concerns of clipping.

Infact, 86 db continuous seems VERY loud to me, and I usually prefer to see the needle bounce around between 70 and 80 db for comfort, which further means that 50W will most likely be "guud 'nuff".

EDIT:

A further consideration: I would love to see the percentage of people that can hear the diffence between 115db SINAD and 85db SINAD. Which further makes me consider - that we are discussing academic things here (as relates to most people).

 

[Everett T]

This doesn't work for many of my speakers, but I can see it having a place, albeit niche more than common.

 

[Haskil]

Beethoven had Jecklin Floats.
Keith

He had much more bulk: several huge acoustic cornets were built for him so that he could hear a little: they were suspended above the soundboard of the grand piano which they completely covered and went up to his head and ears...

 

[Haskil]

peniku8 said:
Not exactly sure who this product is aimed at.

The Internet.

Internet? I don't know this speaker... But I know of high-efficiency horn speakers whose real efficiency is around 98 dB-100 dB which will be particularly happy to be amplified by an amplifier whose signal-to-noise ratio will not make you hear no noise even though the B 100 will deliver 0.25 watts into the coils of the speakers and compression chambers... and it will be able to reproduce without any compression or distortion the instrumental attacks which are not perceived as sound level higher as they are ultra-brief but whose perfect reproduction should not be put aside.
And then, they are small, pretty, still make around fifty watts, which means that in a bare interior, they can be hung on the rear panel with their amplifier, or just placed behind them, direct radiation speaker speakers. whose efficiency is between 88 and 93 dB... that's more people than we think... These small amps which are multiplying are at the same time pretty, efficient, inexpensive and there is therefore another category potential customers who want to see what they can do and who therefore install a second small chain in an office, a bedroom, a large kitchen...

 

[terryforsythe]

A further consideration: I would love to see the percentage of people that can hear the diffence between 115db SINAD and 85db SINAD. Which further makes me consider - that we are discussing academic things here (as relates to most people).

I tend to agree, but have not ever done a blind A/B comparison to confirm. The only thing that I can confirm is that when I stick my ear next to my KEF LS60 tweeters I can hear the noise (a slight hiss), but cannot hear any noise when I stick my ear next to the tweeter in my Elac speakers, which are actively driven (no passive crossover) by a Topping LA90D amplifier. The noise in my KEF LS60s is inaudible to me at 1m, however.

One possible issue I have not investigated is the combination of noise from different components in the system. E.g., if you have a DAC with 95 dB SINAD feeding an amplifier with 85 dB SINAD, does it start to become audible?

 

[EddNog]

I tend to agree, but have not ever done a blind A/B comparison to confirm. The only thing that I can confirm is that when I stick my ear next to my KEF LS60 tweeters I can hear the noise (a slight hiss), but cannot hear any noise when I stick my ear next to the tweeter in my Elac speakers, which are actively driven (no passive crossover) by a Topping LA90D amplifier. The noise in my KEF LS60s is inaudible to me at 1m, however.

One possible issue I have not investigated is the combination of noise from different components in the system. E.g., if you have a DAC with 95 dB SINAD feeding an amplifier with 85 dB SINAD, does it start to become audible?

I can basically press my ear up against the coaxial driver on my LS50 Metas when hooked up to the B100 and I hear almost nothing (the absolute faintest super high-frequency ring that is inaudible more than a few inches away).

-Ed

 

[shuppatsu]

Late response but since this is class B or AB. What’s the short-term output at 1% THD? @amirm was it measured?

(EDIT: From the review) "I tried to measure power at 1% THD but the protection circuit would not allow it. THD would remain incredibly low and then shut down if I increased input voltage. So 86 watts is what you get for max and peak power."

 

[terryforsythe]

"I tried to measure power at 1% THD but the protection circuit would not allow it. THD would remain incredibly low and then shut down if I increased input voltage. So 86 watts is what you get for max and peak power."

That correlates with Amir's data. Topping should revise the specifications, or revise the design to meet specifications.

 

[shuppatsu]

That correlates with Amir's data. Topping should revise the specifications, or revise the design to meet specifications.

I was quoting Amir there, sorry for not making that clear. I think he said that if he knew exactly where protection kicked in he suspects he could replicate Topping's results. Nevertheless, that is one zealous protection circuit! I don't know squat about amps but is this related to the high amounts of negative feedback making the amp unstable once it starts to distort?

 

[Thomas_A]

(EDIT: From the review) "I tried to measure power at 1% THD but the protection circuit would not allow it. THD would remain incredibly low and then shut down if I increased input voltage. So 86 watts is what you get for max and peak power."

Thanks, saw that for 4 ohm, but not 8 ohm. So I wonder what short time burst gives in 8 ohm

 

[terryforsythe]

Thanks, saw that for 4 ohm, but not 8 ohm. So I wonder what short time burst gives in 8 ohm

Good question.

Going back 4 decades, a number of class A/B amplifiers would provide short bursts of power well above their RMS performance. I recall one amplifier specified as being 75W/ch, but it only would do so in short bursts. It's continuous RMS power output was closer to 15 or 20W.

Thinking about that, I wonder if modern amplifiers, such as those from Topping, are capable of providing output well above their RMS rating in short bursts. That could help with short music transients in uncompressed music. If anyone knows, please chime in.

 

[Ismapics]

View attachment 393431

Yes that is clear and thanks. But when measuring power output test use a single tone. Typically 1K or 40hz and that is not music. I am curious why it's not used and reality of power output of music power not just a single frequency.

 

[Ismapics]

The issue with trying to use Pink noise for harmonic distortion is that it is just that, noise, but noise that is generated over the entire audio spectrum at a constant level. The noise masks the harmonics. For example, say you want to measure the harmonics of 1kHz. Those harmonics will be at 2kHz, 3kHz, 4kHz, etc. and, hopefully, be at least -30dB down from the 1kHz signal. But, with Pink noise, there already are signals present at those frequencies, and at the same reference level (assuming a system with a flat frequency response). Thus, you will not be able to get an accurate measurement of the distortion. The harmonics will be buried in the noise.

I understand for measuring distortion, my original post asked about measuring power output. Music clean real power instead of measuring with a 1K or 40hz tone.

 

[amirm]

I don't know squat about amps but is this related to the high amounts of negative feedback making the amp unstable once it starts to distort?

It lets it clip with 8 ohm load so that is not it. I think they are being super conservative to protect the amp from damage. 4 ohm uses much more current so makes sense that protection circuit is well, more protective there.

 

[oleg87]

I understand for measuring distortion, my original post asked about measuring power output. Music clean real power instead of measuring with a 1K or 40hz tone.

Because it really wouldn't tell you anything that distortion vs freq vs power sweeps into various loads don't, but would offer less diagnostic value.