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Archimago: Inside an APx555

Purité Audio

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Just needs an external linear power supply, and silver wiring, everything is built to a budget.
Keith
 

Loathecliff

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Perhaps there should be a health warning for oldies?
The front panel resembles a back panel,
Where are the knobs?
& where's the 'scope?!:oops:
 

Tks

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Wish they got the model of fan in this thing. Why it's not a Noctua for the price they're charging is a perplexity. I should as Amir how loud this thing gets in normal operation due to the fan...

Also, the blue PCBs are a lovely touch.
 

wwenze

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Why people pay so much for Noctua is a perplexity.

One of the fan can be identified as a SUNON MagLev MF50152V2-1000U-A99 DC24V 0.72W
 
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chris719

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Wish they got the model of fan in this thing. Why it's not a Noctua for the price they're charging is a perplexity. I should as Amir how loud this thing gets in normal operation due to the fan...

Also, the blue PCBs are a lovely touch.

Noctua is a newcomer to industrial fans. It's not only the quality of fan, it's that they have chosen a small fan for the amount of air and static pressure they want. Any high output fan is loud. The solution is a larger fan or additional slower fans and fewer obstructions. San Ace, Nidec, etc. are great fans, but anything is going to be annoyingly loud if specified that way.
 

restorer-john

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Noctua is a newcomer to industrial fans. It's not only the quality of fan, it's that they have chosen a small fan for the amount of air and static pressure they want. Any high output fan is loud. The solution is a larger fan or additional slower fans and fewer obstructions. San Ace, Nidec, etc. are great fans, but anything is going to be annoyingly loud if specified that way.

The fans pictured in the APX are Sunon, a respectable brand. What's also interesting is they appear identical which would mean unless they are run at different speeds, they may beat/resonate. Vehicle thermo fans use two different fans with different blade counts and revolutions to create less noise.
 

amirm

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Wish they got the model of fan in this thing. Why it's not a Noctua for the price they're charging is a perplexity. I should as Amir how loud this thing gets in normal operation due to the fan...
It is loud all the time. No temperature sensitivity. I don't know why they think this level of noise is acceptable in a lab.

I put mine in a vented but enclosed rack and that helped cut the noise in half. Still, I cannot work beside it without closed back headphones.
 

FrantzM

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Armchair designing :D

Whatever is in there, works so well as to make of that thing The Standard ...
I've learned through my own mistakes (and successes) that a good design is often more than the sum of parts,...
Peace.
 
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restorer-john

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It is loud all the time. No temperature sensitivity. I don't know why they think this level of noise is acceptable in a lab.

I put mine in a vented but enclosed rack and that helped cut the noise in half. Still, I cannot work beside it without closed back headphones.

Ironic isn't it. Amazing ability to dig down into inaudible levels of electrical noise, but it generates so much acoustical noise you can't use it alongside the audio gear you want to listen to.
 

chris719

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The fans pictured in the APX are Sunon, a respectable brand. What's also interesting is they appear identical which would mean unless they are run at different speeds, they may beat/resonate. Vehicle thermo fans use two different fans with different blade counts and revolutions to create less noise.

I had one on my desk for a few months last year. I didn't hear any beat frequencies or resonances that I noticed, it was just loud. It's not as loud as a 1U server at full tilt, but it's louder than a newer one when the CPU is idle.
 

MC_RME

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Archimago wrote: A reader awhile back had the need to do some hardware work on the Audio Precision APx555 B-Series machine...

Now add the photo where the power supply had been removed and the fan behind it has two screws turned out already I wouldn't wonder if the 'hardware work' was to exchange the fans with lower noise ones. Now the question is: are the Sunon the originals or the replacement? [Detective off]
 

restorer-john

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Now add the photo where the power supply had been removed and the fan behind it has two screws turned out already I wouldn't wonder if the 'hardware work' was to exchange the fans with lower noise ones. Now the question is: are the Sunon the originals or the replacement? [Detective off]

This shot looks like he's perhaps put some padding between the aluminium mounting bracket and the fans- maybe to quieten down cabinet/vibration noise.
fan.JPG


Nice to see Nichicon, Rubycon and Panasonic caps. No Aishis or Su'scons here!
 
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