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DIY Purifi Amp builds

k525

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Hi all

My can someone explain me if it is normal my eval1 S1 switch is not working?
I cannot put in standby the amplifier
 
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idv_42

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Hello!
Recently bought a basic Nord 1et400a.
Looked inside, there are rev d buffers, but without voltage regulators. Instead, the jumper is simply soldered.
What do you think, if I buy Sparkos ss7815/ss7915 and just install them? Or maybe less expensive voltage regulators (lm/ldo)? There is a photo buffer on the nord website (without opamp).
In my amplifier, they look the same, only with opa 1612 and without voltage regulators. The name on the board is exactly the same.

It seems that it looks easy. Opa 1612 suits me perfectly, but regulators are probably better to install.

Thanks!

P.S. Sorry for my english, I am using google translator.
 
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tomchr

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FWIW: I've never been able to measure any difference in the output of the Hypex/Purifi amps with/without the fancy regulators or fancy opamps. I wouldn't change anything.

Tom
 

Synergy4

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FWIW: I've never been able to measure any difference in the output of the Hypex/Purifi amps with/without the fancy regulators or fancy opamps. I wouldn't change anything.

Tom

Did you assemble a Purifi amp with your buffers?
Did you use a IEC inlet medical filter (no Y cap)?
Also, did you use a 8 mm tall mount spacer to align your buffer to the Purifi amplifier?
 

tomchr

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Yes.
No.
8 mm sounds short. I think it was closer to 10 mm. 7/16" maybe. Or 3/8. I forget, but I do plan to document that at some point. :)

Tom
 

Synergy4

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Yes.
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8 mm sounds short. I think it was closer to 10 mm. 7/16" maybe. Or 3/8. I forget, but I do plan to document that at some point. :)

Tom

OK 10mm spacer. Metal spacer?

Do you have a picture of the Purifi amplifiers with your buffers installed in a case?
 

tomchr

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It's important to get the correct length or the connectors won't line up. I just plugged one of the Purifi/Hypex Buffers into the Purifi 1ET400A and measured with a slide caliper. I measure 7.8 mm on one side and 8.2 mm on the other. I'd go with 8 mm standoffs. You can always file them down a bit if they're a touch too long.

The standoffs can be metal or plastic.

I don't have pictures. I mounted the Purifi modules and Buffers on a metal plate that I then bolted to the heat sink of a Takachi HY-series chassis. I put the Hypex SMPS1200 in the centre of the chassis.

I have materials for another amp. I'll document the build as I go along. The first build was more of a prototype.

Tom
 

fraa

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I am confused about buffers.
  • Some people say changing buffers from the original Purifi EVAL1 doesn't improve the sound. It seems to be true; Amir's measurements show that the Purifi EVAL1 slightly outperforms "Nord Three SE 1ET400A Dual Mono Stereo Amp" with Nord buffer using Sonic Imagery 990Enh.
  • So, naturally I looked for an amp with the same buffer as the original Purifi Eval1. I have found:
  • Are the "Basic" Nord and the VTV "based on EVAL-1" the only choice if I want to buy a 1ET400A amp that uses an OPA1612 buffer? Is there any other on the market?
 

idv_42

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As far as I know, only Nord with discrete op amps was reviewed here, not the base model.

I am from Siberia (Russia), but in general, yes, Europe is closer than the United States.
In addition, I do not like VTV externally and internally (some kind of sloppy). But this is of course a subjective opinion.
 

fraa

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As far as I know, only Nord with discrete op amps was reviewed here, not the base model.

I am from Siberia (Russia), but in general, yes, Europe is closer than the United States.
In addition, I do not like VTV externally and internally (some kind of sloppy). But this is of course a subjective opinion.
I see. I am in Japan. I imagine the shipping cost would not be much different from either the US or Europe.
I like the rounded corner design of March, I only wish it had a silver-colored version.
In that respect I think I like the Nord, too. Apollon case seems nice, too but it's the most expensive one.
Speaking of the price, VTV is the cheapest and then Nord and March are about the same.
Without any measurement, it's hard to decide....
I suppose only VTV has been measured (as Purify evaluation version).
 
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boXem | audio

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It's important to get the correct length or the connectors won't line up. I just plugged one of the Purifi/Hypex Buffers into the Purifi 1ET400A and measured with a slide caliper. I measure 7.8 mm on one side and 8.2 mm on the other. I'd go with 8 mm standoffs. You can always file them down a bit if they're a touch too long.
No doubt that you are an EE Tom ;)
Datasheet page 22.
1631969704860.png
 

Rick Sykora

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I see. I am in Japan. I imagine the shipping cost would not be much different from either the US or Europe.
I like the rounded corner design of March, I only wish it had a silver-colored version.
In that respect I think I like the Nord, too. Apollon case seems nice, too but it's the most expensive one.
Speaking of the price, VTV is the cheapest and then Nord and March are about the same.
Without any measurement, it's hard to decide....
I suppose only VTV has been measured (as Purify evaluation version).

You are likely get the best performing amp from March Audio. His attention to detail is higher than most and his ability to service you should be better due to regional proximity. You can get more opinions if you like from others on ASR. As this is a DIY thread, you are off topic and so your query is getting less exposure.

As the (very knowledgeable) @tomchr mentioned, there is no measurable difference in the buffers. But if you are an audiophile who needs to try them for yourself, you are better off with a Hypex NC500-based amp and then will have some spare cash to spend trying different buffers. In that case, would look towards the Euro suppliers. They generally have better quality than VTV. Hope this helps!
 

fraa

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You are likely get the best performing amp from March Audio. His attention to detail is higher than most and his ability to service you should be better due to regional proximity. You can get more opinions if you like from others on ASR. As this is a DIY thread, you are off topic and so your query is getting less exposure.

As the (very knowledgeable) @tomchr mentioned, there is no measurable difference in the buffers. But if you are an audiophile who needs to try them for yourself, you are better off with a Hypex NC500-based amp and then will have some spare cash to spend trying different buffers. In that case, would look towards the Euro suppliers. They generally have better quality than VTV. Hope this helps!
Thanks for the suggestion.

I didn't realize March Audio was based in Australia! They use USD as the store currency. Yes, P452 is very attractive. But the case... If there was a silver or metallic case version, it would probably be on top of my list... But I might still get it.

No, I am not the type who has to try different buffers. I just believe the measurements. The OPA1612-based buffer is used in the reviewed Purifi Eval1 so I thought I'd get one.
 

tomchr

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No doubt that you are an EE Tom ;)
Datasheet page 22.
View attachment 154057

I did read the data sheet. Thank you.

Did you consider that the data sheet may not match reality? The distance from the bottom of the module to the bottom of the board measures 7.8 mm on the 1ET400A I have on my desk. There's also an important dimension missing in the Purifi data sheet: The distance from the top of the PCB to the centre of the connector pins.

You're absolutely right that I'm an EE. And as such I've learned to always check the mechanical dimensions of components in reality as reality often differs from the information given in the data sheet.

Tom
 

Count Arthur

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I did read the data sheet. Thank you.

Did you consider that the data sheet may not match reality? The distance from the bottom of the module to the bottom of the board measures 7.8 mm on the 1ET400A I have on my desk. There's also an important dimension missing in the Purifi data sheet: The distance from the top of the PCB to the centre of the connector pins.

You're absolutely right that I'm an EE. And as such I've learned to always check the mechanical dimensions of components in reality as reality often differs from the information given in the data sheet.

Tom

Had you been a mechanical engineer, you'd have realised that it's quicker to add a washer where the stand offs are slightly too short, than it is to file 0.2mm off the ones that are too long. :p
 

tomchr

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Assuming you can find a washer that's 0.2 mm thick. :) Also, you'd likely be adding multiple washers as standoffs don't come in 0.2 mm increments ... though you could machine them that way.

Tom
 
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