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 2 responses by millercarbon

One thing for sure you are right about: cheap OEM fuses are not anywhere near as good. But I fear your irrefutable info has run into an immovable object in George.  


I am sure that changing a part here and there could change a measurement. However, this us not the usual case.

What is it with people feeling its okay to pontificate and lecture about things they clearly haven't the foggiest about? To an audience chock full of people who do?  

Ralph has more experience in his little finger but even I have enough to know its darn near the OPPOSITE of what this ricevs guy is saying. First swap I ever did was a diode, just a dumb little $8 hexfred, and the improvement was massive! Changed caps- huge. Fuse- ditto. On and on.  

Actually did these things. Actually heard these differences. Just a suggestion ricevs, but I really do think what you should do for at least a while, every time you're all set to start blathering about that which you have no actual experience or knowledge of, type the words, "Of course I have no clue if this is right or not because I haven't done anything even close to this before but...." and then type away. 

Deal?