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"Micro Bamboo Project" : 3E Audio 260-2-29A Stereo amplifier + Micro-Audio PSU

daniboun

Major Contributor
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May 2, 2020
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Hi Amigos )

As promised, I remain faithful to my Diyer position ) After my dual Mono project "Bamboo" I return to the scene with a new project "Micro Bamboo" to pay tribute to Micro Audio and its audiophile grade SMPS630-SO PSU. (46V/13A or 51V/11,5A) Now that we know the measurements of the 3E Audio 260-2-29A module, I wanted to shed a little light on the added value of such a PSU...

About Micro-Audio : Micro Audio Thread

Since I cannot measure its performance, I would stick to a purely subjective opinion based also on the comments of Sami (Micro-Audio). I think that the most informed users know about Micro Audio power supplies and they have a pretty good reputation.
Anyway, I will give you my opinion after a comparative and relaxed listening in a few weeks and therefore later on this same thread )

I also wanted to dispel the myth that this unregulated power supply could not work with the 3E Audio modules.. Those PSUs are fully compatible with full bridge Class D amps and power supply bus pumping should not be a problem (no need to add extra caps). BTW > please note that XRK Audio has developed a TPA3255 (Discovery Warp One) amplifier based on this same Micro-Audio PSU and which is sold for the modest price of $1499 ))

I would like to point out that this project is not oriented towards price optimization but rather to imagine a fairly high-end amp.
Keep in mind that the average price of my project is about : 360 euros

About Warp One amplifier :

Discovery Warp One link 1
Discovery Warp link 2

@MicroAudio + @3eaudio > Thank you for your contribution :)



For those who want to carry out this project, here is the list of components you will need:

Micro Audio PSU

3E Audio 260-2-29A module

Aluminium Case

Gold Plate Binding posts

Bamboo plate
(Any from Amazon with a thickness of 1cm maximum)

Cables set
(If you are resourceful, do it yourself with any quality cooper cable from 1.5mm2 to 2mm2 and faston connectors)

Neutrik XLR

IEC Power Switch

Micro Audio PSU



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DISCOVERY WARP ONE XRK / MICRO AUDIO : $1499
VS MICRO BAMBOO / MICRO AUDIO : $360


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Very cool (my parts are on the way to build my dual SMPS/3E mono setup). Would be interested to hear how it sounds vs say your purifi setup.

Shout out to Sami at Micro Audio, he was super helpful and answered all my beginner questions so if anyone needs a SMPS check them out, super service.
 
Very cool (my parts are on the way to build my dual SMPS/3E mono setup). Would be interested to hear how it sounds vs say your purifi setup.

Shout out to Sami at Micro Audio, he was super helpful and answered all my beginner questions so if anyone needs a SMPS check them out, super service.

Share pictures of your project asap ) thx
 
Nice clean layout and craftsmanship!
 
Beatiful work! :)
 
@daniboun how did you go about screwing the SMPS and 3e board to the case?
Did you tap the holes and screw them in or fix them with a nut and bolt?
I was thinking about tapping the holes just because I've never done it and wanted to learn.
 
@daniboun how did you go about screwing the SMPS and 3e board to the case?
Did you tap the holes and screw them in or fix them with a nut and bolt?
I was thinking about tapping the holes just because I've never done it and wanted to learn.

Best way to drill it is to report the wholes in a paper sheet (A4 is ok).
When you have transferred the marks onto the sheet of paper, place it at the bottom of the case. Before drilling the case, I advise you to attach a masking tape to avoid any scratches. You need M4 screws / bolts for the PSU and M3 for the 3E Audio Module.
Another solution and one that works very well, you can use double-sided thermal adhesive, I tested with a load of 2KG on other project and it is really reliable ) In the first case, don't forget to apply thermal paste to optimize the transfer (a thin layer).
It goes without saying that you will need steel/aluminum bits and you need to drill at low speed.

I shared pictures of my previous project here

 
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I will come back to you as promised. I was able to listen during 4 hours my HD playlist. I am pleasantly surprised by the results. As surprising as it may be, I perceive a good boost at the bottom of the spectrum. I also implemented my new SMSL D-6S DAC which has a 5V output and measured @123.5db under ASR conditions (a must have DAC BTW). The combo works really well, I have a substantial gain in power at equal volume with my first project (3E Audio 260-2-29A + regulated SMPS MP-H250S48).
I don't know to what extent I can say that this Micro-Audio PSU seems to provide a real improvement and more depth in the bass region than with my MP-H250S48 power supply but the result is very convincing.
As in my previous projects, I can also confirm that the amp is perfectly silent even with my ears glued to my AMT tweeters. Which confirms that this Micro-Audio PSU generates very little noise at its output and that the 3E Audio modules have an excellent PSRR.

Still, I don't have any measurements so consider this feeling as a subjective assessment but I still wanted to do the test and it's done)

I am currently working on my next Sylph Audio project, I could get a very good idea in the long term to compare )
 
@daniboun thanks so much for your feedback regarding the PSU, and the amp build, I am planning on doing this now I have seen it done, certainly seems capable! Could I ask what parameters you used when ordering?

Screenshot_20240119_232826.jpg

46V = 13A / 51V = 11,5A?
 
I got the following :
  • Output Voltage (SINGLE RAIL):
    +51 VDC

You cab also email Micro Audio they are super helpful:

The SMPS630-SO with +51V will work perfectly, even its unregulated it may drop to 47VDC under 400W load.

Bruno
 
@daniboun thanks so much for your feedback regarding the PSU, and the amp build, I am planning on doing this now I have seen it done, certainly seems capable! Could I ask what parameters you used when ordering?

View attachment 343202

46V = 13A / 51V = 11,5A?

Got the. 46V = 13A but both fit
For the aux. out it s up to you, I do not use it )

Capture+_2024-01-20-14-10-43~2.png
 
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What is the idle current draw on this amplifier?
 
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does anyone know what the output vs efficiency is and what the temperature derating curve looks like. It would be great if MA would publish this specific data as it is common for others to do so. I have no idea if this 630watt unit requires air cooling for this output, if so how much, and what is the sustained output without forced air cooling
 
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Got the. 46V = 13A but both fit
For the aux. out it s up to you, I do not use it )

View attachment 343294
Thank you, 12V Useful for the preamp section if perhaps retrofitting into a vintage amp, that way one would keep the original front panel controls operational. That's what I'll be doing anyway as they have a certain asthetic appeal to me. Waiting for something nice condition but broken to come up on the Bay of e.

For now I have ordered the original 5A power supply from the French site along with the stereo module. Next month I'll look at purchasing the unregulated, if I feel I need more juice.
 
does anyone know what the output vs efficiency is and what the temperature derating curve looks like. It would be great if MA would publish this specific data as it is common for others to do so. I have no idea if this 630watt unit requires air cooling for this output, if so how much, and what the sustained output is without forced air cooling
@MicroAudio. > any idea here ?
 
I will come back to you as promised. I was able to listen during 4 hours my HD playlist. I am pleasantly surprised by the results. As surprising as it may be, I perceive a good boost at the bottom of the spectrum. I also implemented my new SMSL D-6S DAC which has a 5V output and measured @123.5db under ASR conditions (a must have DAC BTW). The combo works really well, I have a substantial gain in power at equal volume with my first project (3E Audio 260-2-29A + regulated SMPS MP-H250S48).
I don't know to what extent I can say that this Micro-Audio PSU seems to provide a real improvement and more depth in the bass region than with my MP-H250S48 power supply but the result is very convincing.
As in my previous projects, I can also confirm that the amp is perfectly silent even with my ears glued to my AMT tweeters. Which confirms that this Micro-Audio PSU generates very little noise at its output and that the 3E Audio modules have an excellent PSRR.

Still, I don't have any measurements so consider this feeling as a subjective assessment but I still wanted to do the test and it's done)

I am currently working on my next Sylph Audio project, I could get a very good idea in the long term to compare )
Interesting...I have similar experience when I tested my AB class amplifier with two SMPS power supplies. Regulated SMPS power supply sounded thin in bass with limited dynamic headroom. When I connected unregulated SMPS, more depth in bass, better dynamic and soundstage.

Do you have chance to compare this nice D class amplifier project with Purifi design?
 
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