The 3D printer market isn't based on selling $20 cables for $3k based on some bullshit pseudo-science marketing.

In this case, Mark tried to give them the benefit of the doubt, explaining that even if the circuit is a reference design, spending time to match components might make it better than it would be otherwise. It wasn't a bashing, but seemed like a repair video in good faith.

Reading the website of the guy who sells the amps, it's clear he has some ego issues:

https://www.audiodesign.co.uk/index.html

I'm guessing he expected to see Mark fail to repair it, and instead talk about how amazing and advanced his product is.

I remember the first time I saw audiophile cables that had an "electron flow direction" marked on them and I kinda knew right then what this was all about.

Even leads for monitoring brain activity don't do that stuff. And they are monitoring literally mV. Leads and contact patches are often made of silver to capture that stuff too, and they have actual reasons to use silver.

> And they are monitoring literally mV.

Far lower than that. Most EEGs at the scalp are in the 10-100 µV range.

For medical devices, they're profitable by being based on reality instead of just bullshit.

This company is also guilty of some silly cable marketing: https://www.audiodesign.co.uk/styled-26/styled-21/index.html