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Topping B100 Amplifier Review

Rate this amplifier:

  • 1. Poor (headless panther)

    Votes: 28 6.8%
  • 2. Not terrible (postman panther)

    Votes: 24 5.8%
  • 3. Fine (happy panther)

    Votes: 79 19.1%
  • 4. Great (golfing panther)

    Votes: 283 68.4%

  • Total voters
    414
I did that, very low, unfortunately the plot not archived.
So also at -140 dB? I really wonder how they do that with no or a very small idle current. No amount of feedback should be able to iron out heavy crossover distortion.
 
No, I cannot measure that low. Just down to -130dB. Anyway, I find such race pointless, bringing nothing but issues we can see here. But it sells, the SINAD sells to certain group of customers, regardless other parameters.
 
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No, I cannot measure that low. Just down to -130dB. Anyway, I find such race pointless, bringing nothing but issues we can see here. But it sells, the SINAD sells to certain group of customers, regardless other parameters.
If you didn't see any harmonics in a -130 dB noise floor, that is also an excellent result. My question was not about chasing SINAD but trying to understand if there is a weak spot in their design. I still doubt that it is really full class B, though.
 
If you didn't see any harmonics in a -130 dB noise floor, that is also an excellent result.
My limit looks like this:
D10s-E1DA_limit_-2dBFS.png
The noise floor is lower, however the distortion peaks do attack -130dB. B100 does not make it worse.
It may be class B with nested feedback composite amplifier and proper frequency compensation method.
 
Late to the party, but it seems to me Topping is squarely aiming at the 50-100W class D offerings from the usual sustects.
Similar size and cost, yet hugely better performance.

Jan
 
So also at -140 dB? I really wonder how they do that with no or a very small idle current. No amount of feedback should be able to iron out heavy crossover distortion.
Idle consumption indicates a small standing current, so not pure class-B which would not reliably work.
 
A loop probe (for an oscilloscope or spectrum analyzer) can help detect whether it is class-d or not.
 
Idle consumption indicates a small standing current,
idle consumption of the output stage in isolation remains unknown, IMO.

A loop probe (for an oscilloscope or spectrum analyzer) can help detect whether it is class-d or not.
It is no class D. I measured spectrum up to 10MHz, no trace of switching frequency. No rise of THD+N with frequency.

Digital "square" 1k spectrum
1732798205373.png


Sine measured with 25MS/s, no switching frequency
1732798434836.png
 
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The only way I know to get such low distortion in a linear amp is a combined-loop with an opamp and a power output section like a number of // '3886 or similar.
Something like neurochrome.com does, he gets similar performance specs.
This is the modulus-286.

Jan
 

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idle consumption of the output stage in isolation remains unknown, IMO.
Well, we have some 9W of total consumption with zero signal and I would assume at least some of this is burned up in the output stage because there isn't much else that could dissipate significant power. But yes, speculation as of yet, maybe someone could open it and check the temperature on that measly heatsink. If it gets warm then standing current would be the most likely reason.
 
The only way I know to get such low distortion in a linear amp is a combined-loop with an opamp and a power output section like a number of // '3886 or similar.
Something like neurochrome.com does, he gets similar performance specs.

Jan
Yep, it is pretty much certain that this is a design with tons and tons of feedback, so likely a composite with an OpAmp as master and some discrete output stage (with a bit of gain perhaps).
 
9W including power supply consumption or not? Me, I do not have enough info on this.
 
The only way I know to get such low distortion in a linear amp is a combined-loop with an opamp and a power output section like a number of // '3886 or similar.
Something like neurochrome.com does, he gets similar performance specs.
This is the modulus-286.

Jan

I suspected similarly, the Neurochrome amps are an excellent product, though DIY is not for everyone.
Good to see a familiar face on here Jan.
 
B100 has much flatter THDvsFreq graph than Modulus
Look at the scale.
Also,Amir's measurement is with 10dB gain,is it comparable to modulus? (I ask,I have no idea)
 
The B100 has lower 10k-20k distortion than the Modulus. I have no idea how such low 10k-20k distortion can be achieved with a true class B topology.
 
The B100 has lower 10k-20k distortion than the Modulus. I have no idea how such low 10k-20k distortion can be achieved with a true class B topology.
This is the thread where the design was discussed:
 
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