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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

Showing 6 responses by soix

soix
8,809 posts
 
I wouldn’t begin to seriously judge any new audio component until it has at least 100 hours of actual playing time on it — preferably 200 hours.  24 hours?  C’mon man.  Give the thing at least a fighting chance before you finish prejudging it.  Jeez.
soix
8,809 posts
 
To all buying/modding anything, 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
Really?  Not one?  Huh.  Guess they all must be perfectly designed then — and certainly no room for further improvement.  There are these pesky things called cost constraints though.  
these guys are just "snake oilers" and usually fusers saying trust me.
Well that’s just an over-generalized and ignorant statement.  Not everything that provides an improvement is necessarily measurable.  You don’t like guys who mod equipment.  Fine.  That doesn’t mean all or most of them are bad.  If they’re not good they fail, and if they’re good they do well like any other business.  The market is the final arbiter of whether a mod is “snake oil” or not.  Not you. 



soix
8,809 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.
soix
8,809 posts
 
Kudos to you @madavid0 for giving Class D a solid shot. Maybe send it to @ricevs to do some magic mods to it and then we can all enjoy watching Georgie sunshine blow a circuit.
soix
8,809 posts
 
More like calling you out, on your snake oil mods, that you don’t backup with any measurements, just a fusers "trust me it works"
So if there aren’t measurements it can’t work, eh?  Guess you can’t just trust your own ears without some kinda measurement for justification — is that it Georgie?  Are you really that insecure about your own hearing and/or listening ability?

I bought Ric’s original Millennium DAC decades ago and it still works and sounds great, even without measurements.  Hundreds of audiophiles have bought his products and his mods, and he’s earned lots of praise and a solid reputation doing it.  Measure that Georgie.  And by the way, what the hell have you ever produced other than half-assed, armchair quarterback criticism of other people’s work?  Keep on measuring Georgie while the rest of us enjoy listening. 

soix
8,809 posts
 
He’s talking about the module that can be used in various amps, not a particular amp. 
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