Purifi Class D: Junk?

ricevs: In further reading on this subject it appears that there is no “nickname” for the amp under discussion, it is THE name, as it is referred to that everywhere I’ve looked. You sir, are the one confused on this point. Why you conveniently left the actual name of the amp out is anyone’s guess.

In reading the test reports on this amp it is consistently rated very high, some calling it revolutionary or a game changer. Inaudible distortion and zero amp coloration of the sound, pretty much what most would consider a perfect amp to be. Clearly there’s more versions with higher power on the way.

He’s talking about the module that can be used in various amps, not a particular amp. 

Maybe I should have put "nickname" in quotes....I was just letting you know that the Purifi module and the Eigentakt module are one in the same. You notice the name of this thread.....does not say Eigentakt. No biggie.

What is important and that most don’t realize.....and I am repeating....is that the Purifi module is not perfect....it has a sound.....it does have a color....it does not have zero amp coloration.....nothing does. I modifiy the Purifi module and my mods allow much better sound.......I am not talking about a different input buffer, etc. I actually modify the module by changing the output coil, the caps to ground on the output and bypassing the main high voltage power supply with modified Wima caps. These mods do not change the circuit, nor any measurement worth noting. The Purifi module is not the Golden Goose, Golden Egg, silver bullet or whatever, just another step better than the NC500....the last Bruno circuit. There will be plenty of better circuits down the line....sorry guys....this is what is real. However, the Purifi module modded along with the whole amp modded will blow your mind. But next year, there will be something better.....as always. There is no "End Game" in audio......audio is infinite.

I communicated with the owner of VTV about what I've experienced so far and about the upgrade options. He said that he hasn't experienced what I have -- that tells me that his standards for audio quality may be lower than mine. He did mention that the tubed input board makes a big difference to sound stage and so can different opamp options. It seems that the various discrete opamps are more about coloration / tone, is that true? The worst problems I described at the start of this evaluation have mostly solved themselves with burn-in. Improved dynamics and soundstage won't make or break the sound, but the midrange is problematic. What do I mean by this?

Take a piano or a horn. Does it sound like an acoustic piano or could you mistake it for a synth? Does a horn sound like a believable, real horn? Would the better opamps fix this? Why does the standard Purifi opamp which is supposedly very low distortion fail to handle this? The Odyssey I'm comparing this to is by no means an especially high-end amp. It has a lot of current delivery and bandwidth, uses the good Symphonic Line parts, but otherwise appears to be pretty simple design. I busted the newer Stratos even further trying to fix it, now one channel doesn't work at all. The old Stratos I have is too inferior. I went and bought another used Odessey, a high-end Kismet that's only 3 years old. This should out-perform my Stratos and it'll be interesting to compare it with the VTV.

So how bad IS the standard Purifi in the VTV? Will the upgraded input board and discrete opamps move it to another level? Obviously the manufacturer won't say "yeah the base model sucks".

Another interesting finding. I decided to swap out my reference power delivery to the amp: LessLoss level 1 power filtering cable + Firewall 64x from a Furutech GTX-D(r) NCF outlet to a standard black 14-guage power chord from a standard outlet. The difference on one test track was...almost nothing. Maybe the it was a touch muted / muffled on the standard cable, but nothing you couldn't chalk up to audio memory effects. This hasn't been my experience with my linear amps. I wonder if the switching power supply is just agnostic to mains quality -- or it's already so messed up the mains quality won't make a difference?