Cool down and tale some Ritalin. NAD has jus moved from Hypex to Purifi, and the fact that the Purifi modules are also available to DIYers whereas the Hypex NC500 is not does not change the facts: the same designer, Bruno Putzeys, has improved his design while changing company.
What can we expect? similar sound quality, less distortion, some additional features that you do not have to use.
Gu gu gu, wooo woo woo baaaaaaa baaa baaaa (throwing my feces at random people)
Or just normal flexible binding posts (make sure it is copper, and not silver plated. Rhodium or nothing.)
Z-plugs. I use Z-plugs everywhere. Well, not. Not in my food or during sex. But I use them A LOT.
Not sure how audiophonics can bet them for that price, probably from chinese aliexpress sellers, and these are knocn-offs, BUT: 99.99% of cable sound comes from geometry, and the chinese kimber-like wreathed geometry cables are like the real thing. I have those and they are absolutely fantastic (as long as you dont have a NAIM amp, that hates capacitive loads).
The more wreathed, the better. Buy some "12PR" from china, they sound sweert. Terminate them with Z-plugs (crimp them with a hexagonal crimper and good copper cable ends) and you have 99.99% of the quality of those tube connectors.
Roberto, when it works, try to connect it to the DIY powerstrip that incorporates the Schaffner RF/EMI filter and DC Blockers and tell us about the sound.
[IMG, link] http://maty.galeon.com/WP-imagenes/hard/ATL-PSD-08-filtered-mocenigo-inside-with-schaffner.jpg
[IMG, link] http://maty.galeon.com/WP-imagenes/hard/ATL-PSD-08-filtered-mocenigo-with-cables.jpg
[IMG, link] http://maty.galeon.com/WP-imagenes/hard/ATL-PSD-08-filtered-mocenigo-inside-with-schaffner.jpg
[IMG, link] http://maty.galeon.com/WP-imagenes/hard/ATL-PSD-08-filtered-mocenigo-with-cables.jpg
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Now the description of my work.
After some conversations with Kim Nordtorp Madsen at Purifi, I decided to buy a Connex SMPS800Re, which can deliver 800W continuously and up to 1000W burst. I picked it configured at +-54V, even though I could have asked for a customised 65V (more lead time), or even take the 72V one and use the trimmer to go down to 68.8V. In this configuration I have about 160W on 8ohm and 320 on 4ohm. With my very efficient speakers (95db!) I could have bought also a +-25V version.
Then I sourced from Mouser two little 18V switchers manufactured by RECOM. These seem to be the only little switchers at 18V for < 1A (in this case about 0.3A). 24V switchers are also ok, Meanwell also has them, but the RECOM ones are exceptionally low noise, low EMI, and precise. I mounted the two switchers on a little breadboard, as you can seem, with the -V of one tied to the +V of the others and to the ground, so I get -18,0,+18 - for the modulator. This is temporary since I will replace this with a little toroidal and a ATLhifi modified Sulzer regulator.
I use the Connex for +VP, -VP, VDR, VDR_RTN which is internal tied to -VP, and for GND. I need only one GND since the positive and negative rail share he ground, so I have one GND connection "dangling" and will later remove it.
Note that the Connex is, unlike the hypex, regulated, and a lot of DIYers in France and Germany swear by the Connex power supplies, considering them much better than the Hypex ones.
While I cannot do a direct comparison, the little Purifi amp with the stock buffer NOT yet bypassed sounds so much better than the NC500 mono blocks (with hypex smps and a buffer with Sonic Imagery opamps) that I find it quite likely that it is not due to the amplification board alone.
After some conversations with Kim Nordtorp Madsen at Purifi, I decided to buy a Connex SMPS800Re, which can deliver 800W continuously and up to 1000W burst. I picked it configured at +-54V, even though I could have asked for a customised 65V (more lead time), or even take the 72V one and use the trimmer to go down to 68.8V. In this configuration I have about 160W on 8ohm and 320 on 4ohm. With my very efficient speakers (95db!) I could have bought also a +-25V version.
Then I sourced from Mouser two little 18V switchers manufactured by RECOM. These seem to be the only little switchers at 18V for < 1A (in this case about 0.3A). 24V switchers are also ok, Meanwell also has them, but the RECOM ones are exceptionally low noise, low EMI, and precise. I mounted the two switchers on a little breadboard, as you can seem, with the -V of one tied to the +V of the others and to the ground, so I get -18,0,+18 - for the modulator. This is temporary since I will replace this with a little toroidal and a ATLhifi modified Sulzer regulator.
I use the Connex for +VP, -VP, VDR, VDR_RTN which is internal tied to -VP, and for GND. I need only one GND since the positive and negative rail share he ground, so I have one GND connection "dangling" and will later remove it.
Note that the Connex is, unlike the hypex, regulated, and a lot of DIYers in France and Germany swear by the Connex power supplies, considering them much better than the Hypex ones.
While I cannot do a direct comparison, the little Purifi amp with the stock buffer NOT yet bypassed sounds so much better than the NC500 mono blocks (with hypex smps and a buffer with Sonic Imagery opamps) that I find it quite likely that it is not due to the amplification board alone.
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That is a picture of my "the doge mocenigo" power distributor, that I use for everything. It is a massive 8 outlet power distributor with two DC blockers, one on live and one on neutral, and a LARGE Schaffer RFI filter (up to 15A).
I think that the little Schaffer filters that a lot of people put in their builds damage the sound because they are not sufficiently rated for the high current surges that music sometimes asks for. Such a large filter should not have this problem. In fact (I know, this is all subjective, but we are not on ASR) I have noticed no sound degradation at all and instead a slight clean up, more smoothness.
I have not even tried to use the amp with a different power distributor, by the way, all audio equipment is connected there.
I think I have to partially revise myself. The result with the Connex supply is so good that it cannot be only due to the amplifier board. Yes, the components on it have no noble pedigree (Samxon capacitors) but Connex has a good reputation. I believe that the sound quality here is due to the fact that the supply is regulated.
Maybe when Cresnet will provide his own I will try and upgrade it
Roberto
Yes, Alexandar has two versions, one with a broader board and a slimmer but longer board with space for a little trafo. I asked him to assemble the regulator on the slimmer board and cut away (!!!) the part for the transformer, adding screw terminals instead. So I will get a nice 70 x 90 board that will sit next to the 60 x 90 board for the 0.56uV Ultralow noise DAC power supply regulator.
And early next week the universal buffer will be shipped!
I must say I do not understand all the interest in the Neurochrome buffer board for Purifi projects? What makes anyone think the Neurochrome would offer any advantage over Purifi's eval buffer board? The Neurochrome is just another IC based design. Are you at all aware of the performance of the 1612 OPA for example, it is no slouch!
If we are looking for alternatives for an input gain stage, I would hope that some enterprising DIYaudio member who is adept at discrete circuit development might design a discrete alternative specifically for the Purifi amp modules, this could be a great project, and a really good discrete circuit has the potential to outperform IC based designs if a clever and talented individual designs it. could probably be a decent commercial project as well as it is pretty clear there is going to be a demand for alternative buffers for the Purifi modules.
If we are looking for alternatives for an input gain stage, I would hope that some enterprising DIYaudio member who is adept at discrete circuit development might design a discrete alternative specifically for the Purifi amp modules, this could be a great project, and a really good discrete circuit has the potential to outperform IC based designs if a clever and talented individual designs it. could probably be a decent commercial project as well as it is pretty clear there is going to be a demand for alternative buffers for the Purifi modules.
If it qualify as buffer (fully discrete) - this is the Pass Labs Universal Gain Stage, generation 4. If it does not fit the job or qualify as a buffer, then I apologizes.
