In my earlier post, I stated, " All audio devices in use are substantially modified audio devices that, under the hood, no longer represent what the original design brief set out to achieve.
Then there are the custom-designed, commission-built devices "
I should also state that two items in regular use in the system are produced by hand by somebody I have not met, and I do not have knowledge of their credentials for electronics. Regarding the DAC, I know it comes from an individual who has a business producing DACs. Regarding the Kaneta Design SP10 Mk II, which is produced by a person whose training I do not know, but a UK EE, has investigated the circuits and informed me they are produced to a very high standard, which was pleasing to hear.
All other items produced apart from a few interconnects and power cables are produced by the hand of individuals whose credentials are at a minimum an Electronics Engineer.
Having equipment produced by such individuals, especially where there is a very long-term association with audio electronics, does give peace of mind.
On a more serious note, there are audio devices that, if developing a fault, can be quite a risk if the fault manifests. To a lesser extent, there are audio devices that do pose less of a risk, but the keyword is risk.
A CE Mark or other industry-wide certification is pretty much the expectation to be in use in all residences.
Home Insurance Policies will certainly expect to be insuring electrical goods kept and used within the home to have such a type of certification.
Provenance that will prove the electrical goods have been produced by a professional with the correct training and experience is also likely to be an accepted condition for in-use electrical goods.
To anybody wanting to go down the DIY route and produce electrical goods needing a conventional electric power supply. There is the likelihood that, if an incident occurs as a result of the DIY electrical goods being used, resulting in the insurer needing to be notified. There is a strong likelihood that a Home Insurance policy is declared 'Ab initio'.
With the influence of other markets being the source of audio devices, there is also the likelihood that there are multitudes of audio systems across the globe using audio devices without the typical certification being referred to that is authentic, especially audio electrical goods directly imported from a manufacturer. A CE stamp could easily be referring to China Export (CE).
As always in the marketplace, - Caveat Emptor -, is one's very best friend.