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About opus101

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  1. I can't help but be skeptical of the subjective sound when the manufacturer feels the need to feature the opamp (OPA627BP) in its check list of features. Opamps are very sensitive to the power supply quality - I'd mention that I'd given the opamp a particularly conducive environment to work in if I were writing the ad copy.
  2. In this context its output swings of several tens of volts and currents up to several tens of amps. As opposed to the 'signal domain' where domestic voltage swings are typically under 10V and currents are negligible.
  3. Mathematically it can only be anti-correlated noise. When the signal power is higher the noise power can only be lower since the output stage is delivering constant power at all times.
  4. Suggest you get acquainted with measuring real-world amps (not sims) and you'll find the answer for yourself. There's a very simple explanation for that which has nothing to do with the amp itself and everything to do with the measurement device (Audio Precision).
  5. No, the plot on their website shows that number is THD+N - at 10W its clearly noise limited. https://www.purifi-audio.com/eigentakt/
  6. I have a collection of el-cheapo DMMs - my most recent impulse buy :
  7. Definitely it would be worth looking at AverLab as the price is well within your budget (last time I checked I recall the starting point was $3k) : https://www.avermetrics.com/products/averlab/ Picoscope makes a high resolution USB scope for $1200 or so : https://www.amazon.com/Pico-PicoScope-16-bit-Oscilloscope-probes/dp/B0153KEQEW
  8. DSC-1 isn't a ladder DAC its an analog FIR filter. Resistor values don't need to be particularly closely matched as the output is a summation of time-delayed single bit DACs.
  9. Given that you do seem to accept that its CM noise which is the issue and isn't going to be much filtered by the mains trafo its just a small step to envisage a particular design of mains cable to act as a distributed common-mode choke.
  10. In normal (aka differential) mode, this is true. But then you'll also have a bank of reservoir caps to help with the filtering. However its not the case for common mode, particularly if the transformer's a toroidal.
  11. I can only see a marketing advantage myself, in that its different for the sake of being different.
  12. Presumably the 'extremely unique feature' here is simply the use of an EF800 valve in this application. AMR beat AN to it it seems as the now-fairly-long-in-the-tooth DP-777 also had a valve to buffer the S/PDIF signal : https://superphonica.com/all-products/components-digital/digital-to-analog-converters-dac/amr-digital-processor-777-se/
  13. If perchance anyone's interested in learning why unbalanced cables may well be audible from a technical perspective, this long article is one of the best I've come across. It is though pretty heavy going for anyone without an EE background : http://www.soundstagenetwork.com/articles/pete01.htm Turns out that the commonly held belief that only the differential-mode lumped parameters of cables (that's R, L, and C to you and me) make any difference to a cable's sonic contribution isn't all there is to consider in this application. There are the common-mode parameters of the system configuration to consider as well. These parameters, often misunderstood or ignored, play as an important, if not more important, a role than the more easily understood differential parameters.
  14. False - I have a basic understanding of wire and connectivity and I know no such thing.
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