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.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.I did that, very low, unfortunately the plot not archived.
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.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.
OK, thanks. I replied them with a request for a clarification on the actual power output capabilities.It is IEC 60268-3 here in the EU.
My limit looks like this:If you didn't see any harmonics in a -130 dB noise floor, that is also an excellent result.
Idle consumption indicates a small standing current, so not pure class-B which would not reliably work.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 of the output stage in isolation remains unknown, IMO.Idle consumption indicates a small standing current,
It is no class D. I measured spectrum up to 10MHz, no trace of switching frequency. No rise of THD+N with frequency.A loop probe (for an oscilloscope or spectrum analyzer) can help detect whether it is class-d or not.
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.idle consumption of the output stage in isolation remains unknown, IMO.
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).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
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
Look at the scale.B100 has much flatter THDvsFreq graph than Modulus
This is the thread where the design was discussed: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.
38volts, 4amps.Do we know the output voltage of that outboard supply?
Jan