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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
georgehifi's avatar
georgehifi
10,312 posts
 
Really? Not one?
So you would purchase an audio product that was not designed using the Electronic Engineering laws and bench testing?? Good luck with that sunshine.

Or maybe you need to comprehend a little bit better
there’s not one piece of half decent audio equipment that’s any good, that has not been designed using all the EE laws and test/measurement procedures.


soix
9,510 posts
 
So you would purchase an audio product that was not designed using the Electronic Engineering laws and bench testing?? Good luck with that sunshine.
Maybe you need to comprehend better, sunshine. Just because something was designed using the laws of whatever doesn’t mean it was designed optimally or with the best parts. Hence, they can still be improved upon through modding, which was the whole point. It’s not all “snake oilers” as you assert.
georgehifi's avatar
georgehifi
10,312 posts
 
Hence, they can still be improved upon through modding,
Of course they can, but using Ohms law, Kirchhoff's law with bench test measuring gear etc, if they didn't use these then they are just "voodooist" and "snake oilers" like fusers are, that prey on the gullible like you by the sounds of it. 
tweak1
3,666 posts
 
GFi
I never said they aren’t stupid expensive for what they are, but I have used many different versions of hi-end fuses over my DECADES as an enthusiast and as a B & M dealer back in the early 2000s (Audio Tweakers), so any name connection to evs is a coincidence

Once again you assume too much
milpai's avatar
milpai
2,399 posts
 
Alright, it is "sunshine from down under" on yet another Class D thread.Problem with george is, he feels we should trust his hearing and not our own.
Ask him for concrete evidence on Class D stuff, and he will cry uncle and start posting Nelson Pass's quotes. He does not have the full knowledge of class D. If you don't believe me, just wait for this thread to move on a bit OR go to other class D threads. And on top of that he calls on others as "policing" when he does the most himself. Looking at his past posts, I think he has some issues. Like digging up 13 year old posts and start calling out names. I suggest, ignore his posts and move on.
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