a stock Hypex buffer boardThere is nothing wrong with that buffer, Putzy's not an idiot to release a Hypex product that kind of bad sound ****
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?
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?
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You say there is nothing wrong with it and at the same time you say there is a "massive improvement" when you bypass it. You cannot have it both ways. Every op amp....every regulator......every everything....has a sound. So all buffers, etc will sound different. Some will sound bad, some are OK, some are good, some are really good, some are great. If you bypass it and you get a massive improvement.....then certainly, it is not great. |
Wake up!! Did you come down with the last shower? It doesn’t sound ****, like your making out. And of course, leave out any buffer regardless of how good if one can with high output source, and you’ll reap those benefits of extra transparency/dynamics and slam, by going direct into the Class-D module with no buffer at all in the way. And that Hypex buffer is a perfect match with the Purifi module, that’s why it’s called and marketed as a buffer. It something else the OP is hearing, and you know what that leaves, the Purifi module itself! |
And that Hypex buffer is a perfect match with the Purifi moduleHave you heard them in combination? I have, and I found them not a good match together. Others feel the same way, for example https://www.audioasylum.com/cgi/t.mpl?f=amp&m=238411. VTV seems to be the only vendor offering this combination. I think there's a reason why nobody else is doing it. |
Have you heard them in combination? I have, and I found them not a good match together.Are you saying it sound like **** like ricevs, and it’s a bad design bad sounding buffer? Or the impedance match is no good as a buffer? then any buffer will have the same problem. Do you think Putzey made a bad one on purpose? Because it is a "simple buffer", made by someone who could make one in his sleep, using good sounding opamps, which is hard to get wrong. He could teach just about anyone how to make one in 15 mins, even adjusting the gain of it Here is one using the opa1632 opamp https://ibb.co/njDHP1H Pin 6 is a misprint, should be 5. Pins 3 and 6 are then for + and - from the powersupply. No, like I said there’s something else the OP is hearing, and all that’s left is the Purifi itself. Cheers George |
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