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DIY Purifi Amp builds

Luc

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i find the purifi buffer board sufficient.
i hesitated taking the nord buffers, but pricey... the nice thing is to put the opamps of your choice ;-)
for me the neurochrome buffer is of little to no interest
 
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JimB

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Thread Starter #1,384
Based on documentation R6_A1/A2 resistors should not be present for HW mode.
View attachment 72905

My board looks like follows.
View attachment 72907
There is a smd element without description but with white line.
My board seems to be somehow 50/50 in HW/SW mode :)
Do you have similar smd in place of R6_A1/A2?
I have four boards - none are populated there.
 
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OK, Purifi gave me a few more details regarding this mono input buffer, and I'll just copy and paste it here from the email they sent me. Pretty sure they won't mind, as if this were confidential they likely wouldn't have shared it with me. It's free marketing for them :)
  • 14dB SE/Ballanced gain stage based on OPA1612 with Panasonic thin film 0.1% resistors and Kemet NP0 linear capacitors.
    total system gain is 27dB as for the EVAL1 kit
  • Gain stage can be bypassed
  • Very low noise and low output impedance linear regulators for the gain stage and for analog circuits on the 1ET400 module
  • Available with XLR/Speakon connectors or without
Prices aren't final yet and they hope to have it on the webshop by early June. Their current thinking is a price of 150USD for the fully stuffed version and around 135USD without XLR/Speakon connectors.
The board is manufactured and tested in DK
Any News on this ?
 

Luc

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But the Nord is more than 350 Euro per Channel, thus isnt cheap as well, right ? This ist the Same price than the amp channel
Yes, you're right. Very expensive and that's why i did not do that from the beginning. although i really would like to be able to switch opamp and voltage regulators easily
 

March Audio

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SMPS in STANDBY mode power consumption is 1.9W

SMPS in RUN mode power consumption is 10.7W Amplifier not connected

Hope that answers your question.

Thanks
Im no expert on the regulations, but doesnt the EU now mandate that standby power must be below 0.5 watts?

Might not be relevant for DIY products
 

somebodyelse

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JimB

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Thread Starter #1,394
Interesting...
Are you using J3.2 READY signal in any of your boards? I’m curious what voltage level you have there.
I'm not using that and am not able to check it right now. Hopefully someone else can test that for you to compare. It should be 3.3V logic.
 
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Maybe someone can help me with some feedback. Thinking about 3 Stereo Purifi amps, but in one case. Looking at Apollon Audio they use 3x Hypex 1200 for 3 Channel ! Looks a bit weird with an amp rated 450W, right ?
My idea was one microaudio with 700w or 1000w for Stereo but in comparison this is way less than what Apollon uses.
 

starfly

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Question about wiring up an AC/DC converter. I'll be using the Meanwell LRS-35-12 converter, and it has the following block-diagram:

meanwell.png


And the converter looks like this:

meanwell.jpg



So I wire up Live and Neutral A/C, and send DC 12V to the SMPS for standby circuit, etc.

This converter also has a ground terminal. I was planning on attaching this wire at the same spot I have grounded my IEC A/C socket (on the chassis rear-panel; I confirmed with an ohm meter that any other grounding points in the chassis flow to that point). Is that the correct way to do it?
 
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JimB

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... This converter also has a ground terminal. I was planning on attaching this wire at the same spot I have grounded my IEC A/C socket (on the chassis rear-panel; I confirmed with an ohm meter that any other grounding points in the chassis flow to that point). Is that the correct way to do it?
Your 'converter' is a mains power supply. You should ground it as you say. Did you consider a lower power unit, without ground?
 
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