Wadax phono at operation

Javier of Wadax explains in details the Wadax Trio operation as a phono stage at the AE 3rd Super high end show 2015 (Cessaro-Vertere-Wadax-Zanden-Tripoint-Dalby room). 

The picture attached shows some of the measurement summary data: before and after ‘mapping’. Many parameters are not shown for simplicity, like timing info, other non-linearities, etc.

There are 5 graphs in the picture:

1- On top trace, the natural response is shown. 

From 25Hz to 12KHz, amplitude swings by an amazing 4dB. If we extend to 20KHz, this difference widens to 12dB!. These are the TYPICAL and natural losses that appear on any phono system. These are due to cartridge design, setup, loading.. 

2- On trace below, predicted output. 

3- On lower trace, the real measured response AFTER system mapping is applied. Differences across the audio band are now 0.1dB vs 12dB of the natural response of the system.

4 and 5- On lowest leftmost, Left to Right differences: 2dB differences across the audio band. They are reduced to 0.15dB after mapping. This ensures soundstage is totally stable and new spatial clues are resolved.

Some conclusions from this graph: 

a. Huge natural losses appear in all phono setups. As shown, there is not a big interest in what happens about 40KHz, as the cartridge-loading-setup combination will filter eventual HF content on the disc. At 40KHz, the measured level with our master reference lacquer was -25dB (!). 

Furthermore, disc cutters apply a sharp low pass filter to the original music being transferred to disc, to eliminate everything above 20KHz. HF content can (and likely will) damage the cutting heads used to cut the master.

b. So phono stage amplitude response at 100KHz or 200KHz has no impact in terms of amplitude. However, when using fully analog circuitry, phase response accuracy at the top limit of the spectrum is related to bandwidth. In the digital domain, you can arbitrarily adjust phase (time) and amplitude independently, which allows the freely choose analog bandwidth and preserve all timing info.

c. By the time the analog content from the disc reaches the input connectors of ANY phono stage, many losses have already occurred. No matter how perfect the analog phono stage is.

So basically, the digital domain allows to reverse the contamination that occurs during phono reading process. Soundstage is reconstructed, timing information restored, power spectrum naturally re-equilibrated.