2. amps-preamps
  3. 162284-76532

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
 


George would call them Snake oilers

Don’t try to flip this, to another direction, your the only one here on this thread.

I have the highest respect for those companies.
(except for one that bridges his stereo amps into monoblocks and claims them as better performing amps), measurements/tests will call them out as lower performing, with one only plus of higher wattage.

BTW this statement of yours a couple of posts back, another bit of............? It flows forth like the Nile. 
It is best just to ignore George. Let him have the last word or it will go on forever

Post removed 
tweak1
3,666 posts
 
+1 soix
milpai's avatar
milpai
2,397 posts
 
Maybe we should use a new word for people like this. How about Anti Snake Oiler or ASO.
@ricevs , that is a good one :-). Assuming that george is the biggest ASO and he complains on fuses and other stuff like modding. But what surprises me is the -ve bias against Purifi and other class D modules that have come up recently. The folks on ASR have shown with measurements how good the Purifi module is and the potentials it has. Subjectivists and objectivists both agree on this one. It looks like he has "personal" agenda/motive against Class D. The only thing I could think of is that maybe Class D amps do not gel very well with his attenuators and hence is trying to discredit them? Not sure. Beats me.Well known designers still have to make a living and not run a charity. Why would they promote other designs over their own? And the quotes that they made, which george often mentions, are from "how long ago"? Technology changes, so we should see improvements in the new Class D amps, compared to the ones from a few years ago.

twoleftears's avatar
twoleftears
5,318 posts
 
And we're still waiting for the LSA Voyager, which should be out soon, perhaps even before that $9500 Technics.
More to discover