27-Sep-2019, 16:11
I heard back from Mathieu, here's a copy of his email (which he asked me to share), plus a spectrum picture of my audio sample. Note his 'next steps' comments, anyone any views on this?
I finally took some time this afternoon for an analysis.
Attached is the spectrum of your audio sample:
- The S-shape is due to the RIAA curved applied to the incoming stream. Without this curve it would be flat.
- The reference level is to be measured at 1kHz : approx -99dBc
- The bass level at 20 Hz is 20dB higher, as expected
- The treble level at 20 kHz is 20dB lower, as expected
- The response of both channels is identical, no mismatch
- The response is deprived of any unwanted tone or resonance (which would immediately appear over the spectrum)
Feel free to share this picture and/or my comments on the forum. The obtained performance in no load mode is to my opinion excellent.
Next steps would be to redo the same measurements while playing a record with a sinewave in order to achieve and measure the SNR figure.
The perception of noise has always to be compared with the intensity of the reproduced signal (or the music)
I do use this one (can be found in many online shops)
https://store.acousticsounds.com/d/35532...t_Up_Tools
Have a good week-end
Mathieu
I finally took some time this afternoon for an analysis.
Attached is the spectrum of your audio sample:
- The S-shape is due to the RIAA curved applied to the incoming stream. Without this curve it would be flat.
- The reference level is to be measured at 1kHz : approx -99dBc
- The bass level at 20 Hz is 20dB higher, as expected
- The treble level at 20 kHz is 20dB lower, as expected
- The response of both channels is identical, no mismatch
- The response is deprived of any unwanted tone or resonance (which would immediately appear over the spectrum)
Feel free to share this picture and/or my comments on the forum. The obtained performance in no load mode is to my opinion excellent.
Next steps would be to redo the same measurements while playing a record with a sinewave in order to achieve and measure the SNR figure.
The perception of noise has always to be compared with the intensity of the reproduced signal (or the music)
I do use this one (can be found in many online shops)
https://store.acousticsounds.com/d/35532...t_Up_Tools
Have a good week-end
Mathieu
Devialet Expert Pro 220, ATC SCM40 speakers, Pro-Ject Xtension 9 turntable, Chord Signature XL speaker cable
