Nah... the noise nuke from Bob actually does something measurable with said tube hybrid.
This is because of the design of the amplifier. The downside of said design is low PSRR (PSSR). Not so with the Zen Can (internal converter/regulator).
Said hybrid amps also have certain features (by design) that sound/measure
purposely different and is measurable (see Bob's and Amir's measurements).
It is proven by its design and follows actual laws of physics, there is no 'magic' involved. In fact there are even settings on said amps that you did not find on other amps (before said designs came out).
You see, sometimes a brand just wants some design that differs (and was why I was approached for those designs and not just one manufacturer either).
Just like the Zen Can
Signature is designed well after the Sennator was created (an amp that has a fixed HD650 EQ in it) again, ask Thor.
Sure... different amp design, different filter (target) but you get the idea, dedicated EQ amp.
There is no magic there either. It is different by design.
You don't see me recommending to use the Sennator with anything other than the HD650/6XX.
Just like you omit the fact (in your questions on the web) that you have the Zen Can
Signature HD6XX and plan to use it with very different headphones than what it is intended for.
You should take Bob's and Marvin's advice.
TBH, I would seek simpler solutions and/or go slow. The amount of money and time f'ing around with optimizing power supply / exhibiting power supply neurosis can put toward a better amp and better gear.
Nitsch Pietus Maximus is a great amp and is a solid performer. I personally prefer it, if I had to choose between it or the Zen Can.
If you want to power anything else than the HD650/6XX you really should either buy another amp instead of trying to use it for what it is not intended for.
There is much more to be gained (with other headphones) by buying
a suitable amp design.
And to answer the other thing... sometimes manufacturers sell something (yes, also the pro manufacturers) because of a demand. When the demand for something is high enough manufacturers will make it as it brings in more money. On top of that ... tweaks usually have a very high profit margin.
The decision to make some add-on or option, more often than not, is born of demand, not to 'improve' some design or patch a design flaw (immunity for common mode/leakage of a design). Ask me how I know.
Poking fun at Thoren has got to be the silliest thing.
I am not poking fun at Thorsten... In fact I like Thorsten and discussing audio things with him.
I also quite like Bob by the way.
On some things (usually subjective things) I just see it a little different.
And yes ... I do read SBAF (I was even a member at Changstar for a while... till it blew up) and read other sites as well. Is there a law against that ?
For fun, and for certain info that isn't found anywhere else.
I just do not register nor post there.
Also I am not ASR nor do I represent ASR. I am just one of the members here. One that isn't very strict on 'specs' either. ASR does 'suit' my line of thinking more than other forums and is why I am active here and not elsewhere.
When you ask for an opinion at ASR (it is widely known what type of audience resides at ASR) that has to do with electronics/headphones chances are I respond.
I try to help in that case (including you) but some people just want to hear something different than what I (or others at ASR) have to say. So be it.