Phonoclone 3

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rjm

rjm

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I'll let Burson and GP fight it out as to who copied who, but yeah, same comment applies in the absence of hard evidence to the contrary.

I've uploaded a couple of 44.1kHz recordings, with no sample rate conversion. They sound quite a bit better, but still not as accurate as 2496.

Here is the complete list of phonoclone 3 sample files:

1644 .wav:

Handel Concerto recorded at 1644

Nights on Broadway recorded at 1644

Nights on Broadway CD version

2496 FLAC:

Glen Gould : Well-Tempered Klavier

Carpenters : Goodbye to Love

2496 .wav (short samples):

Beegees Sample

Mozart Piano Concerto Sample
 
rjm

rjm

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I have no idea what that is. Artifacts at 16 kHz and 32 kHz point to the A-to-D conversion as the cause... relating I imagine to the brick wall filter at 48kHz.

Recordings were made with an Onkyo SE-200PCI soundcard.
 

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rjm

rjm

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Werner said:
Not the notch per se, but rather the impression
that the signal contents above and below the notch
seem to be each other's image. As if the signal
was sampled in the most lousy way at 64kHz!
Click to expand...

Sheesh, will I ever get it right?

Reinstalled the drivers, and double checked all the settings. It looks like the line input sample rate might have been something other than 96 kHz at some point in the pipeline, as with every setting I can find now set to 96 kHz, the results appear correct. I did a loopback test with test tones at 1kHz and 30kHz, both were reproduced correctly. I also used the test tones to determine the unity gain input volume setting, so the data below is the correct scale now for the phonoclone output.

The plots show the noise spectrum for the card with the inputs disconnected, the phonoclone powered up but no record playing, a section of the BeeGees record with no music playing, and finally of Nights on Broadway.
 

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rjm

rjm

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The problem turned out to be a bit esoteric:

The VIA Envy24HT controller in the soundcard, and the drivers that go with it, are 192 kHz 24 bit in/out. Onkyo only specifies the soundcard for 96 kHz input, 192 kHz output. I had set the input sampling rate to 96 khz in Audacity, but left the VIA controller at 192 kHz.

The soundcard really doesn't do 192 kHz input sampling even if data can be acquired at that frequency. There are odd peaks and mirror folds due to aliasing errors at 32, 64 and 96 kHz. See the attached plot.

I'm pretty sure the 44.1kHz recordings were ok, but I've deleted everything just to be on the safe side. Here's a new version of Nights on Broadway, 2496 FLAC, recorded at 0dB, so it's at the same volume as you'd hear the phonoclone out directly.

Nights_on_Broadway_new_2496_0dB_FLAC.flac
 

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