Topping B100 Amplifier Review

[Panelhead]

I can only relay what Topping recommended. For average efficiency speakers use the LA90 Discrete. For high efficiency speakers or lower listening levels the B100’s. Never mentioned B200. Maybe cost.
I think I can hear the difference between B100’s and PA5II. So 125 SINAD vs 105 SINAD. The difference was audible when listening to low level strings and piano.
I was using a Micromega integrated. It is very quiet, but sounded distorted at normal volume in comparison. On orchestral works if clean recording had some fuzz. Never heard it before listening to B100. Using same RAW-MDA1 dac as source and volume control. The redundant source selector and volume control in the Micromega may contribute.
The B100 are 124 - 125 SINAD. The THD and noise are below the intrinsic level of an APx555B. Topping had to amplify the output by 40dB to measure it with an APx555B. Then divide by a 100 to get the numbers published on their website.
If Amir had used this technique the four Topping amps that top the chart would not all measure the same. Doubt that a digital chip amp, digital discrete amp, Class AB amp, and Class B amp all measure the same - 120 SINAD.
Topping ranks them as B100 (125), B200 (122.3), LA90 (122), and LA90 Discrete (121).

 

[NTK]

If I switched from an ~81dB SINAD to a 120dB SINAD amp such as this B100, will there be an audible difference?

Currently running a ROTEL RB-1582 MkII amp which hasn't been measured here so let's assume it has a mean ~81dB SINAD. Let's assume my amp has similar measurements to this.
My source is the old(ish) Topping D90 also measured 120dB SINAD. Speakers: Revel F206.
I mostly listen to low, "conversational" volumes so I doubt ever go over the power limits of both the Rotel or Topping.

Posting my question here as I don't think it warrants a dedicated thread. Thanks.

Most likely not. The Rotel's SINAD of 81 dB was distortion dominated. Audibility of distortions is at about -60 dB and therefore this single SINAD number "looks" worse than it is. The more relevant 5 W signal-to-noise ratio wasn't too bad at mid 90's dB, which shouldn't be a problem with the roughly average sensitivity of your Revel.

The Rotel landed within the green zone in Amir's review, so while not state of the art it is fully competent.

 

[Panelhead]

The relevance of SINAD to your listening depends on several factors. How loud you listen, type of music, and speaker sensitivity all factor in.
Many systems output a watt or two during peaks. Most of the time output is milliwatts. The SINAD numbers trend up as power output goes up. This slope can be seen in the graphs.
These rankings are measured at 5 watts. They would be a little different if done at a lower power level. When looking for an amp I looked and compared what the amps measure at 50mW. The TDH+N vs output power graph. That is 40dB below the output used for SINAD.
Since your Rotel is measured here that comparison is easy to do if trying to compare performance. The power level to select for comparison is not as easy.

 

[HakanC]

If I switched from an ~81dB SINAD to a 120dB SINAD amp such as this B100, will there be an audible difference?

If the only difference is SINAD my guess is: no
But my other guess is that there may be other differences then only SINAD

 

[typericey]

Thanks for all your responses, appreciate it. I'll most likely keep my amp until it dies.

 

[FERCSA]

One of the most important thing people forget to mention is gain-staging. Always use your gears in the 80+% range. The B100 has 3 different gain settings. Use whatever is best for you.

Other thing I usually say to justify high sinad devices is that they have reserve. In case you use your dac as a preamp the sinad and other metrics degrade if you're not using it at 100% especial close to 0%. Others mentioned this already.

Last thing when you considering B100 or other amps. What is the maximum input voltage? Because for example the B100(in low/mid) can accept higher voltage than the usual 4V(xlr) what a consumer hifi dac/preamp/wte can put out. This is the reason I drive my B100s in low setting(0dB!) with a pro audio gear at 6.9V(@100%)! So we are back to square one: gain-staging.


There was a question about a Rotel amp. I dont want to go into this too deeply because it's my subjective opinion but I had Fosi V3 stereos with higher sinad(89) just before the B100s and I was able to pick the B100. To sum it up: is it worth the extra money? Not really only if you can afford it and want the best.

 

[Jimster480]

Most likely not. The Rotel's SINAD of 81 dB was distortion dominated. Audibility of distortions is at about -60 dB and therefore this single SINAD number "looks" worse than it is. The more relevant 5 W signal-to-noise ratio wasn't too bad at mid 90's dB, which shouldn't be a problem with the roughly average sensitivity of your Revel.

The Rotel landed within the green zone in Amir's review, so while not state of the art it is fully competent.

For me, the answer would be yes. -60 for Distortion is quite low.... but with speakers we are talking about the factors of the room, etc.
However, as someone else mentioned; it depends on the music, its volume, quality of recordings, etc.
I could tell the difference between 80 and 105 SINAD devices. Beyond 105... I have tried but I cannot isolate anything with confidence enough to say that it is indeed different.

 

[totti1965]

For me, the answer would be yes. -60 for Distortion is quite low.... but with speakers we are talking about the factors of the room, etc.
However, as someone else mentioned; it depends on the music, its volume, quality of recordings, etc.
I could tell the difference between 80 and 105 SINAD devices. Beyond 105... I have tried but I cannot isolate anything with confidence enough to say that it is indeed different.

Sometimes Sound Differences are not SINAD related but caused e. g. by a lower damping factor of Amp A in comparison of Amp B. So the frequency Response of the speaker may change a bit - or even a "bigger bit" if non pfft Amps are compared with pfft-Amps.
The brighter sounding Amp is perhaps perceived as the higher distorted amp.

 

[totti1965]

I can only relay what Topping recommended. For average efficiency speakers use the LA90 Discrete. For high efficiency speakers or lower listening levels the B100’s. Never mentioned B200. Maybe cost.
I think I can hear the difference between B100’s and PA5II. So 125 SINAD vs 105 SINAD. The difference was audible when listening to low level strings and piano.
I was using a Micromega integrated. It is very quiet, but sounded distorted at normal volume in comparison. On orchestral works if clean recording had some fuzz. Never heard it before listening to B100. Using same RAW-MDA1 dac as source and volume control. The redundant source selector and volume control in the Micromega may contribute.
The B100 are 124 - 125 SINAD. The THD and noise are below the intrinsic level of an APx555B. Topping had to amplify the output by 40dB to measure it with an APx555B. Then divide by a 100 to get the numbers published on their website.
If Amir had used this technique the four Topping amps that top the chart would not all measure the same. Doubt that a digital chip amp, digital discrete amp, Class AB amp, and Class B amp all measure the same - 120 SINAD.
Topping ranks them as B100 (125), B200 (122.3), LA90 (122), and LA90 Discrete (121).

Hi Panelhead,

The differences in @amirm measurements and those of topping are caused by the fact, that Amir does it with a more rigoros non A-weighted setting. The Topping guys are reaching 125 dB only because it is A-weighted!

@amirm is using the same „trick“ for measure these perfect Amps as Topping does. He is well aware that he has to increase the output of the best Amps by 40 dB, because they are reaching the intrinsic limits of the APx555!

Maybe you have „golden ears“, and can differentiate between 105 dB and 125 dB, but as soon as you reach - 116 dB as a SINAD level, everything is fine, even from a theoretical Standpoinf: the physical / biological System „Man“ is not able to reach deeper into a tone signal.
It is simply the absolute limit (for practical purposes (music signa!) even 70 dB may be enough!).

Yours,

thorsten

 

[totti1965]

If the only difference is SINAD my guess is: no
But my other guess is that there may be other differences then only SINAD

Yes, most likely the damping factor over the frequency range plays the biggest rule:
Differences my be huge!

 

[totti1965]

There was a question about a Rotel amp. I dont want to go into this too deeply because it's my subjective opinion but I had Fosi V3 stereos with higher sinad(89) just before the B100s and I was able to pick the B100. To sum it up: is it worth the extra money? Not really only if you can afford it and want the best.

Fosi V3 vs Topping B100: This was exactly „my way“.
I also was able to pick up some differences (perhaps pfft related?) and like the B100 more. The difference is subtle but it is there! Many folks here don’t believe me.

 

[Panelhead]

If think we are apples and oranges. The 5 watt SINAD does not track the 50mW SINAD. I listen at 50 mW and less.
I listening at 5 watt level very long my hearing may suffer. Even horns will mask electronics at 100+ dB.

 

[Sokel]

If think we are apples and oranges. The 5 watt SINAD does not track the 50mW SINAD. I listen at 50 mW and less.
I listening at 5 watt level very long my hearing may suffer. Even horns will mask electronics at 100+ dB.

SINAD is a ratio, unless something elaborate like RME does with its level control happens, it will follow a nice, straight declining line, like shown at the THD+N vs Level measurement, or power vs THD+N .
That measurement though (the levels) , is controlled by the analyzer here, it may differ a little if controlled by DUT alone (if it has level control of course, most power amps don't )

 

[Jimster480]

I wonder what kind of setup is needed for me to actually record how much power my speakers use... so that I could see if I Could possibly use these amps in the future.
Since they only have 50W output to 8ohm.

 

[terryforsythe]

I wonder what kind of setup is needed for me to actually record how much power my speakers use... so that I could see if I Could possibly use these amps in the future.
Since they only have 50W output to 8ohm.

If you know your speaker's SPL @2.83V and your listening SPL, you can estimate it using this spreadsheet on Google Docs:

Amplifier Power Requirement

docs.google.com

*Read the notes to the right of some of the entries as they explain the values to enter.

 

[staticV3]

I wonder what kind of setup is needed for me to actually record how much power my speakers use... so that I could see if I Could possibly use these amps in the future.
Since they only have 50W output to 8ohm.

-choose a track that you like
-open it in an audio editor of your choice (Audacity, Gargeband, Audition etc) and note down the track's dBTP level
-at the end of the track, add a 5s long 60Hz sine at 20dB below the dBTP level, e.g. -0.8dBTP -> -20.8dBFS sine wave
-play the track and adjust volume to preference
-let the track finish, then use a basic $10 multimeter and measure the AC voltage of the 60Hz sine at the end by touching the probes to either the left Plus and Minus speaker outputs, or the right ones. It does not matter which probe goes to Plus and which to Minus, only that both probes touch the same output channel.
-do measured voltage times ten and you get the peak RMS voltage that your Amp had to output to play the track at your preferred loudness.

You can then compare that to the B100, which can output 20V at 4Ω and 23.66V at 8Ω.

Converting that to power levels is easy by doing voltage^2/impedance=power, but it's not really necessary here.

 

[terryforsythe]

-choose a track that you like
-open it in an audio editor of your choice (Audacity, Gargeband, Audition etc) and note down the track's dBTP level
-at the end of the track, add a 5s long 60Hz sine at 20dB below the dBTP level, e.g. -0.8dBTP -> -20.8dBFS sine wave
-play the track and adjust volume to preference
-let the track finish, then use a basic $10 multimeter and measure the AC voltage of the 60Hz sine at the end by touching the probes to either the left Plus and Minus speaker outputs, or the right ones. It does not matter which probe goes to Plus and which to Minus, only that both probes touch the same output channel.
-do measured voltage times ten and you get the peak RMS voltage that your Amp had to output to play the track at your preferred loudness.

You can then compare that to the B100, which can output 20V at 4Ω and 23.66V at 8Ω.

Converting that to power levels is easy by doing voltage^2/impedance=power, but it's not really necessary here.

Does that factor in transients? As pointed out to me by @Sokel somewhere around pp. 39-40 in this thread, and confirmed by testing my own speakers, instantaneous transients are not insignificant. If I remember correctly, in my test peak transients were about 12dB EDIT: I just went back and looked at my graph, it was 15dB - 18dB over my listening volume, but that was only with 4 songs tested. They can go even higher, especially if uncompressed recordings are being played. If I remember correctly, Sokel's measured transients were higher than mine.

 

[torgeirs]

If one first is at it. Step the volume down 10 dB every 30 seconds. When the music is gone you find the noise level that is good enough for your setup.
My guess is 5 volts and -70dB.
But some need other values to enjoy music, so its an interesting experiment for all of us

 

[staticV3]

Does that factor in transients?

Yes.

 

[torgeirs]

Does that factor in transients?

Yes
If the music have high transients the 60 Hz will be loud. If it is 2010 britpop it will be much less loud.
The ear compares rms values
High transient = high crest factor = high peak to rms value. In normal recordings at least