Received my Pulse X yesterday, but like others on various forums, there are popping/buzzing sounds when changing sample rates. When the popping/buzzing sounds are heard, the Pulse X display flickers (the flickering display with popping sounds was reported by a certain online personality too). Popping/buzzing sounds are especially prolonged and loud when switching to higher sampling rates (e.g. when Pulse X switches to 176kHz momentarily when playing DoP, before switching to DSD64; while 176kHz is being displayed, sometimes for as long as a few seconds, the popping/buzzing sounds are heard throughout, until Pulse X finally switches to DSD64, then the popping/buzzing sounds stops; sometimes the popping/buzzing sounds does not stop until I stop playback)
Thankfully, having heard of similar reports on various forums, I tested my Pulse X using my Xiaomi Pistons... and not using my HD800 or on my main system with Bowers & Wilkins 802 Diamond speakers.
I have a Geek Out 450, and on the same Windows PC with Foobar2000, I do not get such prolonged and loud popping/buzzing sounds with switching sample rates. On my Geek Out 450, I get a single pop/click sound when switching sample rates, or a double pop/click sound when playing DoP (first pop/click for switching to 176kHz momentarily and then second pop/click on switching to DSD64)
My Pulse X is on the latest firmwares: MCU is 2.6, Main is 2.0, Light Harmonic Control Panel shows v1.5
~Leon