Measurements and conclusion
Contents
We measured the Yamaha with our Prism dScope III. We took both digital and analog measurements. Power supply noise was measured with a Tekbox LISN and Picoscope 5000 series digital scope/spectrum analyzer.
Measurements Yamaha HA-L7A
Not entirely surprisingly, the Yamaha HA-L7A measures quite nicely. We see a particularly low noise floor of just over -140dBFS. That’s just very good. The interference test even shows a value below -155dB. That we do not see often: this pre-amp / headphone amp is really quiet!
Crosstalk is extremely good with values around -140dB. Dynamic range idem: 122.7 dB, which amounts to over 20 bits of resolution. The linearity test confirms this picture: the whole picks up around -130dB and is tight from -120dB.
Jitter we were only able to measure with the Jtest (which we are not a fan of). We see values around 7ps, which is fine. We don’t see anything crazy in the entire spectrum either.
The power supply is also nice and quiet: it couldn’t be otherwise, of course. The only thing we see is a small bump in common-mode interference. No drama.
It is striking that the frequency response is slightly different when we take the analog input. The digital inputs are slightly straighter in the response measurement.
