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
 
Most high end companies choose parts and execution by ear after they have done the measurement game.  This is because they know that a ton of stuff that changes the sound cannot be measured.  

Here is a list of companies that do this.....George would call them Snake oilers......but he won't:  NONE of these companies shows measurements before and after changing parts and execution.....NONE.

1. Wilson Audio
2. Audio Research
3. Gryphon Audio
4, Constellation Audio
5. Parasound (designed by John Curl...who uses parts for their sound)
6. Magico
7. Kef
8. Odyssey
9. VAC
10. Von Schweikert Audio
11. Rowland Audio
12. Merrill Audio (used Synergistic fuses in older amp)
13. GR Research
14. Spatial Audio
15. etc. into infinity

Almost all tube manufacturers....they pick caps, etc. by ear....and they don't measure any different.

Almost all cable manufacturers

Most equipment stand manufacturers......I mean, can you measure a better stand?

There are companies that do little parts tweaking like Pass, Cherry Audio, Schitt, etc.   However, there are more that tweak than do not....by far.  Please George, call all these high end companies out.  Let them know you will never listen to another Wilson speaker, etc. until they show measurements that confirm their sonic pickings......Go, George......do your duty.

riccitone
229 posts
 
Consider trying an XTZ Edge? Ice power, I know...but very well received by many, and has a gain adjustment to help match with most pre(s):

https://www.xtzsound.com/reviews/edge-a2-300
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
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