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Purifi 1ET400A / Hypex NC500 Input Buffer

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#42
polywine said:
where cani download the manu? I wanna check what cables and power supply are.needed.
casshan, where did u get the power cable? it should be a y cable? single socket from hypex smps to two buffer boards
Click to expand...
If you buy the buffer from web, you’ll be given a link to download manual. The cable set is brought from Purifi accompanied with 1ET400A. I build a mono block so no Y cable is need.
 
#44
polywine said:
thanks, hows the sound? Do you also have eval buffer? Eval use +-18 and i guess i need another LPS for Neurocrome.
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I haven't not yet finished the amplifier.... Purifi also has EVA1 with two amplifier module and buffer. Because I build a 7 channel amplifier for AV purpose, I bought 3 EVA1 and 1 1ET400A. EVA1 has buffer but 1ET400A not.
Neurocrome buffer can add external regulator, you can buy their PCB for LPS if you need.
 
#45
casshan said:
From manual, pinout of J2 is compatible to pinout of J4 of SMPS1200A400. If I user external voltage regulator (brought the PCB) on input buffer, should I configure J4 and J4 of SMPS1200A400 to provide unregulated voltage to the input buffer?
Click to expand...

Pardon my belated response. DIY Audio has apparently decided to no longer send me email updates for this thread. Or maybe I forgot to subscribe. My bad...

Yep. If you use an external regulator, you need to remove the two jumpers on J4 and install an external regulator. Then set the SMPS1200 to provide the unregulated voltage.

Tom
 
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#46
BTW: These Buffers are quite popular. I've sold about 2/3 of the first batch and am working to put the second (larger) batch into production. Those of you who are on the fence about ordering may want to get off the fence and onto a computer to place your order if you want to take advantage of the lower price of the first batch.

Just saying...

You can order yours here: Purifi 1ET400A / Hypex NC500 Input Buffer – Neurochrome

Tom
 
#48
Just received buffer, thanks Tom!
 

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#51
daniboun said:
Can you tell me if I made a mistake in the above picture ? Just need to connect a RCA plug into my NC250MP module :
Click to expand...

I suggest reading the NC250MP data sheet. You can download it from Hypex, though they might require that you register on their website before they'll let you download it. You can find the NC250 product page here: Hypex Electronics B.V.

The attached figure is a screen grab of the relevant section of the data sheet. You'll notice that the input to the NC250 is differential, thus, requires three connections: IN+, IN-, and GND.
Elsewhere in the data sheet, you'll notice that the input impedance of the NC250 is 47 kΩ.

Any audio source is able to drive 47 kΩ, but not all sources offer a differential (or balanced) output. So you have a choice:
  • Use a pseudo-differential connection (as shown in attached figure)
  • Use one of my Universal Buffers to make a single-ended/unbalanced to differential/balanced converter

Personally, I would fit the amp with an XLR input connector so you maintain the differential connection. The XLR standard pinout is:
  1. GND
  2. IN+
  3. IN-
Female connectors are used for inputs. Then use either an RCA-XLR adapter or a pseudo-differential cable, which you can make yourself. Alternatively, connect the RCA shell to pins 1 and 3 on J4 and the RCA centre to pin 2.

Note that this thread is about my Purifi 1ET400A / Hypex NC500 Buffer, which is not useful for the NC250. Should you have further questions related to your NC250 build, I'm sure you'll be able to find help in the Class D forum if you post a thread there.

Best of luck with your build.

Tom
 

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#54
In my (perhaps not so humble) option, there isn't much to the voltage regulators. That hasn't stopped people from tweaking and perceiving a difference, though. I provide the option for those who wish to tweak, and I will happily build you a set of regulators, but I cannot measure any difference with/without the regulator as long as you obey the voltage requirements for the Buffer and the amplifier module.

Tom
 
#57
Hi Tom. i just bought a couple of these boards on swap meet. i need info on how to wire them up and i cant located them on your website? is it one of those policies that you only provide them to the original owner?

do these input buffers need a separate power supply?
 
#58
In this picture this board seems to be the output stage while the universal buffer is the input buffer. im confused as to what is happening here? why does there need to be this board on the output just before the speaker terminals? doesnt the amplifer board provide the amplified signal directly to the speaker? why is it called input buffer if it has the speaker level signal? I thought i knew what was going on but now im really confused:

IMG-0506-Dx-O-1-large.jpg
 
#60
I suggest you contact the original owner for the detail about this build.

The green boards were an early prototype of the Purifi/Hypex Buffer. It looks like the original owner bypassed the buffer board and wired the Universal Buffer directly to the input of the amp module. That's why you see that "flyover" coax cable. The prototype for the Purifi/Hypex Buffer did not have a differential output. That was added before the circuit went to production. That's probably why the amp is built that way.

If you contact me by email, I'm happy to provide the documentation for the Universal Buffer for you. Just include a picture of the board in your email so I can get the correct documentation to you.

I do not have documentation written up for the prototype Purifi/Hypex Buffer board. I'm happy to answer your questions about it, though.

And, yes, it's compatible with the SMPS3k as well.

Tom
 
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