Can hi-end cables benefit less expensive electronics?

No cable in my experience has taken a bad sounding component and made it great all of a sudden, specially putting an expensive cable on a lower priced component. Cables are fine tuning. So much over hyp and pseudoscience on cables in hi end audio its not funny. Don't get me wrong I can hear a difference with better/different cables but not like some peoples claims of  "huge improvements, life changing" line of BS. Fine tuning and maybe placebo more likely.  Or trying to justify their prices payed for them. Sure they can and do help with fine tuning. 

No reason in todays engineering and manufacturing ability's for $10,000+ speaker/power/etc cables. 

After 35 years working in defense combat systems engineering, where we have many sensitive components that require specific types of cabling, it just makes me laugh at what we (audiophiles) pay for cables. Lets not even get into the claims of some of these companies.

Use your own ears and be subjective of what you are listening to and listen over a period of time, switching back and forth. Don't fall for the hyp or claims of the manufacturer and don't fall for the " need something new" for the sake of something new i.e. dopamine hit when you get a new toy. 

serblinfan OP

. . . I only regret selling Furutech DPS 4.1, which added some warmth that I loved

’Warmth’ can be manipulated in various ways. If a system is fatiguing and has distortion, then warmth becomes a band-aid. Especially, if the room has hard walls, floor & ceiling - with no acoustical treatments. Warmth can mask subtle nuances in the music - such as triangles or snare drum brushes.   Further up the ladder of good systems, the degree of warmth is dialed in for a personal preference.

I've used inexpensive DH Labs cables in my office system (Cambridge integrated amp and NAD cd player).  Never tried anything better, but I doubt it would make much difference.  Speakers are decent Wharfedale and a NHT subwoofer.

What I wonder about is my older systems.  Adcom GFA-555 amp, NAD 1300 preamp, and Vandersteen 2C speakers.  Back in the day, Monster was the good stuff.  In hindsight, I wonder how well a system like this might have performed using good cables... 

Great question. Of course there is no absolute without trying. But here goes.

I actually bought a transparent cable and put it on inexpenive components long ago. It sounded terrible. But that was because I had a very noisy fatiguing solid state system with very revealing speakers. Cardas golden (reference) speaker cables warmed things up and sounded much better. I put the transparent in the closet.

Twenty years later I had good quality components and those same Transparent cables sounded fantastic. So, it is a mater of what the sound of your components. Transparent will get the most out of them if good. I use Transparent throughout. Looking at your system my guess is that the Transparent would be a great investment and net you better sound now and in the future.

That’s my guess.

BTW, I have no idea why but speaker cables, interconnects, and power cords of the same manufacturer and level tend to do exactly the same same thing for the system. I find this strange, but it has been true for me all the time

Is a high-end digital cable in some cases able to make it a worthwhile investment in a setup which is not top hi-end?

A good digital cable is critical and worth exploring and investing in, but how much to invest is very system/budget dependent.  In my system a better digital cable made a very significant improvement and regretted waiting so long to upgrade, so with your current DIY cable I’d certainly encourage you to try something else.  And getting a better digital cable will obviously also pay dividends if/when you upgrade other components, so there’s that.  Why are you locked into the Transparent cable that may or may not work best for your system/tastes?  Whatever you do, and as with all cables, I’d make sure you can try the cable first so either use a dealer who will let you do that or buy used.  Just my $0.02 FWIW, and best of luck.