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
ricevs
1,543 posts
 
Can anyone save us from Georges constant negativity?

I own one of those Behringer amps.....there is nothing in there that resembles anything made by IcePower.  Even if it is a custom IcePower it is junk.  i don't even like it that much on woofers....and I modded it.
art_boston
45 posts
 
So if you're not running an amp with a regular power transformer and a lot of capacitance available for the class D amp to feed on, you're probably not hearing what it can do.

Exactly true. That's what allows the H2O Audio S250 Signature to run Scintillas with ease and quality, albeit with old B&O modules. I'll take this old school approach with current class D anytime!
oldhvymec
5,101 posts
 
Ok here is the part I don't get. HOW anyone can charge 7500.00 for any Class D or 20-40,000.00 for any class a or A/B. That is the my problem.. NO BODY is that good...

I can see a Rolls-Royce costing 1/4 million, I understand that. The back right side door is a lot more complicated than ANY SOTA amp EVER made. But please explain, why THEY get 200.00 an hour for building an amp in 48 hours and expect ME or anyone to pay for it.. NUTTSO comes to mind..

Jesus help me.. I helped build and repair dams, bridges, aircraft, buildings, rescue people from other countries, on a job in Brazil pulling guys out of fresh bores 1000 feet underground. 50.00 an hour? MAYBE.

God give me strength.. something is wrong.. Where is the Roller I been waiting for to show up on my door step with a big ol thankyou and a RED ribbon.. AND Buffy the belly dancer as the chauffeur.

She gives wonderful hand massages. :-)

Now everyone's point it? Some people like apple, some people like oranges. Me I like mangos.

Regards
djones51
4,947 posts
 
They charge it because someone will pay it. 
audioguy85's avatar
audioguy85
2,018 posts
 
Most class D is junk, except the Rogue Sphinx and some class D Marantz, The Ruby comes to mind, as well as the pm10.
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