Purifi Class D: Junk?


So, from the previous thread about high-end class D the Purifi module was brought up. I decided to get a cheap example from VTV, a simple stereo unit with a single Purifi module and matching Hypex SMPS. Standard input buffer. I got it in yesterday. First impression wasn't what I was expecting: weak, congested dynamics is what stood out to me. I expected greater expression through my ProAc D30Rs. The other problems such as poor soundstage, thin / boring character, etc, I marked up to needing burn-in before evaluating. So it's been 24 hours, I would still expect to get at least the high control / damping of high end class D and dynamic power, but it's just not present.

Could it be an impedance mismatch? Other manufacturers selling the Purifi with their custom input buffers are reporting 47k Ohms. VTV doesn't say in the manual or on the site. I checked the Purifi data sheet which reports...2.2k Ohms on SE???? That can't be right?? That's absurdly low! Am I reading the right spec? My preamp has an output impedance of 230 Ohms. Can someone confirm that the stock Purifi has this ultra-low input impedance?
madavid0
No doubt, to those that do not listen.  Those that listen with an open mind....they actually experience something......so they really KNOW.  

Most high end audio is the blind (or deaf....he he) leading the blind.  What I mean by this is practically no one actually does listening tests at the micro level.  Most just A/B components and make generalizations and guesses.  In drag racing there is only 5 things that matter.....horsepower, weight, drag, traction and gearing.  And these things can be all measured.  In high end audio there are an infinite number of things that change the sound that cannot be measured.  Unless you actually A/B wire.......you cannot know about wire.....unless you actually A/B removing a non needed AC filter and replacing it with a great sounding AC inlet then you do not know what it does......on and on....into infinity.  The switching power supply that in the VTV and a lot of other Ncore and Purifi based amp has two poles of AC filtering built in......why would you want to add smaller inductors before this and encase them in a STEEL case?  You already have some good filtering.  More is not better unless it is done at a super level.  Have you ever removed a power switch from a power amp and listened?  In the VTV the switch is a two pole.....so there is a switch on the hot and neutral......Have you ever tried a super fuse?  If you have not you know nothing about the sound of fuses.....on and on.  This game is not simple.  Every single thing you do makes a sonic difference.  I have been tweaking since 1976......I first removed fuses from the original Theta DAC back in the late 80s and heard how bad the fuses were.  This is not new information.  Most reading this have no idea what I am talking about because they have never done these kinds of tests.  Only about 5% of audiophiles are DIY people and out of those maybe 5% of those really do serious listening tests.....So, we are talking about a very, very small percentage of people that do serious micro stuff listening tests.  Back in the 50s and 60s the audio game was way more DIY oriented.  You could go into any "hifi shop" and buy individual speaker drivers, xover parts, tuner parts, kits of preamps and amps from various manufacturers, etc.  Today......very few have any idea how anything works.....just plug and play.  This is why the game is so complicated because there are no rules.....it is just every man for himself and there is no consensus on practically anything.   If you look at dragsters....they all look like the same person made them all.....because the dragster people all KNOW what works....and they mostly agree.  High end audio is just the opposite.  However, if you are smart and read a lot you can find gear for very little that will blow your mind and make you cry and feel the love and joy of life tingling in every cell of your body.
No doubt, to those that do not listen. Those that listen with an open mind....they actually experience something......so they really KNOW.
This is something a fuser would say when taken to task. 🤦‍♂️
Yes, I believe in fuses........as in BE and LIVE together.  A belief without an experience is like reading a novel and thinking you know about love.  Words are not an experience.  To KNOW anything in audio.....you have to listen....and with an open mind....

When I post about something it is because I have experienced it.  If you post about something you have not tested....then you are just guessing or wanting to be right or heard......belief systems are bogus.....we need to BE LIVE our truth.