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

Showing 1 response by tradeontheweb

tradeontheweb
43 posts
 
George asked me to comment here. Happy to do so as I have no bias either way.
But having bought, sold, reviewed & listened to enough audio for 3 lifetimes, I do have an opinion.
I had the pleasure of hearing George’s Hypex NC500 mono’s driven direct (no Buffer) on his secondary system yesterday. Driven from the MSB Discrete R2R dac, it would have to be the cleanest and most dynamic Class D reproduction I’ve heard to date. And I’ve probably heard 30+ different Class D Systems over the years. Extremely low, coherent & powerful bass that remained tuneful at all times. Musical structure & impact maintained across all frequencies. 
For Class D and in fact any amplifier technology, the sound was superb by any measure.

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