Thoughts on Neutralaudio X-Drei, wrt BSG QOL

Based on the limited descriptions that are available, QOL and X-Drei seem to me to be intended to do two completely different and unrelated things.

QOL appears to be intended to somehow extract/recover/restore information, apparently phase-related, that "is already present in recordings, but [is] hidden in conventional reproduction."

X-Drei appears to be intended to reduce, modify, or otherwise make more benign, ultrasonic and rf frequency components of the signal, that might be difficult for the power amplifier and/or the speakers to handle without audible side-effects. In looking at the signal waveforms shown in their writeups, keep in mind that what distinguishes the sinusoidal, triangular, and square waves that are depicted as inputs are high frequency harmonics. Although they don't show time scales in any of the diagrams, those harmonics are presumably at ultrasonic and rf frequencies, because presumably the device would not be designed to alter harmonics or other spectral components that are below 20 kHz.

I would therefore expect the effects of X-Drei to be highly dependent on the particular amplifier and speakers that are being used, and on how gracefully they would be able to handle those ultrasonic and rf spectral components in the absence of this technology.

IMO.

Regards,
-- Al

Hi Al, that's a really helpful comparison of the effects of both units.
Since they work on different facets of the signal, what is your hunch as to how they might work in series ie one after the other between pre and pow? And if you feel this might be positive which sequence would you choose?
Thanks for your time, Marc.

Almarg, I would be interested in your opinion of the QOL's oscilloscope data as provided on the BSG website.

Others have speculated that it's a middle/side phase processor similar to devices used in mastering process.