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

[daniboun]

I can't help help but wonder if you aren't looking at this the wrong way. You state that the Mornsun et al. drop in power output when used without fans, but imply that the Micro audio does not, so you ask if this could possibly result in perceived audible effect as stated.
The Micro audio will derate its output as well, just as any other power supply. The difference is Micro audio does not publish detailed specifications and measurements as is the industry standard, despite several requests on these forums for them to do so.
We know exactly how much power a Mornsun will put out, at what temperatures, what air volume is needed to maintain a higher stable output etc. We have no idea what the Micro Audio will put out beyond a peak power output of 600 watts.

this is in addition to supposed sonic improvements from using the Micro Audio ostensibly owing to it's unregulated output or supposedly greater output power and such...
So if I use 55 watts at a given point, the 700 watt max output supply will sound better than the 500 watt supply?
this takes nothing away from efforts to actually measure the Micro audio setup so as to verify if the perceived differences are real. This is after all audio SCIENCE review and thank goodness for that

It is because I am skeptical myself that I want to push the test to the end. I am convinced that the truth will come from measurements. With supporting figures we will probably be able to find out more about this Micro Audio PSU and eliminate any subjective reasoning.
I share your opinion regarding the insufficiently detailed technical documentation concerning the Micro Audio PSUs but nevertheless the feedback seems generally laudatory...
Wait and see now )

 

[MicroAudio]

I can't help help but wonder if you aren't looking at this the wrong way. You state that the Mornsun et al. drop in power output when used without fans, but imply that the Micro audio does not, so you ask if this could possibly result in perceived audible effect as stated.
The Micro audio will derate its output as well, just as any other power supply. The difference is Micro audio does not publish detailed specifications and measurements as is the industry standard, despite several requests on these forums for them to do so.
We know exactly how much power a Mornsun will put out, at what temperatures, what air volume is needed to maintain a higher stable output etc. We have no idea what the Micro Audio will put out beyond a peak power output of 600 watts.

this is in addition to supposed sonic improvements from using the Micro Audio ostensibly owing to it's unregulated output or supposedly greater output power and such...
So if I use 55 watts at a given point, the 700 watt max output supply will sound better than the 500 watt supply?
this takes nothing away from efforts to actually measure the Micro audio setup so as to verify if the perceived differences are real. This is after all audio SCIENCE review and thank goodness for that

The SMPS630-SO is designed for music reproduction and is therefore not able to deliver its maximum output power long-term.

The RMS value of any common music signal generally doesn’t exceed 1/8th of the maximum peak power.

The data sheet will be updated in SMPS600-R2 in the next month or two.

And for the fan, you don't need a fan to run the SMPS630-SO.

If you are looking at the continuous output power of the SMPS630-SO it's 400W for 3 minutes and 600W for 30 seconds.

The output voltage of the SMPS630-SO will drop with load, all the details will be published more accurately in the next datasheets for REV-2.

REV-2 will be tested in 14 days, and based on the results orders will resume after that.

If there is enough interest in REV-2, we can run a group buy at a good price.

Thank you

Sam

 

[SMen]

I can't help help but wonder if you aren't looking at this the wrong way. You state that the Mornsun et al. drop in power output when used without fans, but imply that the Micro audio does not, so you ask if this could possibly result in perceived audible effect as stated.
The Micro audio will derate its output as well, just as any other power supply. The difference is Micro audio does not publish detailed specifications and measurements as is the industry standard, despite several requests on these forums for them to do so.
We know exactly how much power a Mornsun will put out, at what temperatures, what air volume is needed to maintain a higher stable output etc. We have no idea what the Micro Audio will put out beyond a peak power output of 600 watts.

this is in addition to supposed sonic improvements from using the Micro Audio ostensibly owing to it's unregulated output or supposedly greater output power and such...
So if I use 55 watts at a given point, the 700 watt max output supply will sound better than the 500 watt supply?
this takes nothing away from efforts to actually measure the Micro audio setup so as to verify if the perceived differences are real. This is after all audio SCIENCE review and thank goodness for that

Thank you @jlx , you have expanded on my question well. @daniboun has asked for measurements of the Micro Audio power supply so hopefully some answers will come back from his initiative. My question was also really if anyone had tried with / and without fan for any perceived differences in power. I am also wondering how an smps might vary in terms of power relative to heat. There is a discussion on power supplies also here : https://www.audiosciencereview.com/...p-with-power-supply.52325/page-3#post-1916497.

The Mornsun is
48V 11A (25CFM fan cooling)
48V 6.7A (Air cooling)

A lower powered Meanwell (EPP-400-36) I have for another project is quoted at
36Vdc at 11.2A (25CFM fan cooling) 400W.
This drops to 250W with air cooling. So using a calculator I am assuming 36V 6.9A

So what difference 6.7A vs 11A? And how does the Micro Audio measure to compare? This would be interesting.

​

 

[daniboun]

Thank you @jlx , you have expanded on my question well. @daniboun has asked for measurements of the Micro Audio power supply so hopefully some answers will come back from his initiative. My question was also really if anyone had tried with / and without fan for any perceived differences in power. I am also wondering how an smps might vary in terms of power relative to heat. There is a discussion on power supplies also here : https://www.audiosciencereview.com/...p-with-power-supply.52325/page-3#post-1916497.

The Mornsun is
48V 11A (25CFM fan cooling)
48V 6.7A (Air cooling)

A lower powered Meanwell (EPP-400-36) I have for another project is quoted at
36Vdc at 11.2A (25CFM fan cooling) 400W.
This drops to 250W with air cooling. So using a calculator I am assuming 36V 6.9A

So what difference 6.7A vs 11A? And how does the Micro Audio measure to compare? This would be interesting.

​

You must also consider the Current VS Voltage in the equation
And that varies depending on the loads @4R or 8R

 

[SMen]

You must also consider the Current VS Voltage in the equation
And that varies depending on the loads @4R or 8R


View attachment 359880

Yes, thank you, so it will be interesting to see the actual supply power of your micro audio smps with passive cooling and if this could be a factor in your listening experience.
Do you by any chance have the equivalent power output table for the 3251 chipset? I am investigating both. Just been through your Sylph thread - can't find equivalent table - would be useful.

Great initiative! It is a pity Micro Audio could not publish their ratings.

 

[jlx]

Thank you @jlx , you have expanded on my question well. @daniboun has asked for measurements of the Micro Audio power supply so hopefully some answers will come back from his initiative. My question was also really if anyone had tried with / and without fan for any perceived differences in power. I am also wondering how an smps might vary in terms of power relative to heat. There is a discussion on power supplies also here : https://www.audiosciencereview.com/...p-with-power-supply.52325/page-3#post-1916497.

The Mornsun is
48V 11A (25CFM fan cooling)
48V 6.7A (Air cooling)

A lower powered Meanwell (EPP-400-36) I have for another project is quoted at
36Vdc at 11.2A (25CFM fan cooling) 400W.
This drops to 250W with air cooling. So using a calculator I am assuming 36V 6.9A

So what difference 6.7A vs 11A? And how does the Micro Audio measure to compare? This would be interesting.

​

I I recall correctly, we know that the sinad increases a tiny bit by running the 36 vdc vs 48vdc, but no human can tell 103db from 105db so who cares. it's just soooo far beyond the human range of perception...clearly the max amp power output is less with the lower supply voltage, any other audible differences between the 2 supply voltages (as they both are within the module's specified requirements) would indicate a poorly designed amp module

Frankly any power supply meeting the specs given by the amp maker should have no effect on audible output. If it does then either the given spec requirement is flawed or it is poor amp module engineering. Either way it reflects badly on the amp designers..

so given the limited additional info given for the SMPS630-SO I would guess its true maximum continuous passively cooled power output is between 300 & 350 watts so it is comparable to the Mornsun 550. I suspected this from day one.
I will be using the Mornsun 550 and the 750 soon as the specs presented in their white papers are superb, these are medical grade supplies with reasonably high MTBF as well. I also love the small size. As much as I think Micro Audio makes a quality product, I am very much put off by the lack of technical documentation (this is not a good thing) and feel this lack of transparency led people to think it was a more powerful supply than it actually is.
I am not a believer in magical audio only power supplies as I do science and measurements not vodoo & mystical claims so often put forth by the audio industry, so take that for what it is..
FYI I've built dozens of amps using, Hypex, Pascal, Icepower etc over the years. Built an Icepower 1200as1 amp last week, for subwoofer use, with defeatable opto-isolated 12v trigger and 2 internal 5v Noctua 60mm fans (running at 4vdc) activated by a solid state relay. The fans cool the input T-former and (more importantly) the output inductor, but this is an entirely different conversation and I do not want to hijack this useful thread

 

[MicroAudio]

@SMen

"Great initiative! It is a pity Micro Audio could not publish their ratings."

Could you please tell me what ratings you are looking at, that will allow us to generate them soon.


Thanks

 

[MicroAudio]

@jlx

" As much as I think Micro Audio makes a quality product, I am very much put off by the lack of technical documentation (this is not a good thing) and feel this lack of transparency led people to think it was a more powerful supply than it actually is"

I appreciate your efforts.

Where did you spot my claim that the SMPS630-SO is more powerful than other supplies?

I agree that the documentation needs updates and as I mentioned already it will be updated.

We are not misleading anyone here nor forcing them to buy our products.

Thank you

 

[SMen]

@SMen

"Great initiative! It is a pity Micro Audio could not publish their ratings."

Could you please tell me what ratings you are looking at, that will allow us to generate them soon.


Thanks

I think that passive cooling power and active cooling power would be useful. And ripple and noise. Also (and forgive me I am working from memory here looking at your products) the impact on noise of using a capacitor bank, and when to use it and when not.

Just a couple of thoughts.

I am not an expert but @daniboun has taken it on his own shoulders to have your smps measured to better explain and understand his findings when listening with the 3e module (which were of course entirely positive).

 

[jlx]

@jlx

" As much as I think Micro Audio makes a quality product, I am very much put off by the lack of technical documentation (this is not a good thing) and feel this lack of transparency led people to think it was a more powerful supply than it actually is"

I appreciate your efforts.

Where did you spot my claim that the SMPS630-SO is more powerful than other supplies?

I agree that the documentation needs updates and as I mentioned already it will be updated.

We are not misleading anyone here nor forcing them to buy our products.

Thank you

where did I say that YOU MIcro Audio made that claim ?? I did not. Are you trying to diminish the value of my opinion by referencing statements I never made??

I clearly said "this lack of transparency led people to believe.."
I feel that owing to the model designation with NO additional technical clarification (until yesterday) led many people to think it could output 600+ watts passively cooled with no limitations (since none were noted) vs the Mornsun's 550's 312 watts (clearly noted in their white paper) passively cooled. I use Mornsun purely out of convenience, other manufacturers follow the same conventions in their spec sheets.

but since you brought "we are not misleading anyone" up, I also see in your spec sheet under:
OUTPUT POWER (CONTINUOUS) typical 12 amps (For +55VDC as example) ............... so we get 660 watts continuous ???? nope
OUTPUT POWER MAIN 600 WATTS

There is not a single note or word specifying that these levels are for a whopping 30 seconds (so NOT continuous) and are in fact continuous ONLY with active cooling and are in reality around 300 to 350 watts passively cooled continuous. This is relevant as the amp built in this very thread and most other builds here do not use active cooling.

Furthermore, under:
THERMAL CONSIDERATION it may hit 55C in hot environments, therefore the FAN Output is there to be used, disabling the FAN will decrease the life of the components in the power supply. However, the SMPS will run without any issues without the FAN, but it is recommended to enable the FAN

not a word is given about true continuous power output requiring fan cooling
In the last two months I have asked at least three times on these forums, as have others, for clarification on this matter and for a thermal derating graph....

Based on the above, I do find your literature is misleading to say the least. I have corrected people several times as they seem to think your supply was 600 watts passively cooled in their comparisons to other products wherein they correctly reference the much lower continuous passive operation specs of those supplies.

I leave it to others to draw their own conclusions

 

[daniboun]

For those who took the time to read the measurements carried out by Stereophile regarding the Warp Discovery amp which uses the same Micro Audio @48V + XRK TPA3255:

"The Warp 1's output power is specified as 150W into 8 ohms (21.8dBW) and 250W into 4 ohms (21dBW). With our usual definition of clipping—when THD+noise reaches 1%—I measured a clipping power of 110Wpc into 8 ohms with both channels driven"

The 3E Audio + Morsun LOF550 gets 92W@8R at the knee....
This should give some clues )

 

[SMen]

For those who took the time to read the measurements carried out by Stereophile regarding the Warp Discovery amp which uses the same Micro Audio @48V + XRK TPA3255:

"The Warp 1's output power is specified as 150W into 8 ohms (21.8dBW) and 250W into 4 ohms (21dBW). With our usual definition of clipping—when THD+noise reaches 1%—I measured a clipping power of 110Wpc into 8 ohms with both channels driven"

The 3E Audio + Morsun LOF550 gets 92W@8R at the knee....
This should give some clues )

Yes I read this, but you have made the comparison in terms of measurement analysis between the Stereophile review vs the Morsun.

Instead I think that we need the manufacturers to give measurements ... and for ASR to hold them to their measurements ... and then you with your listening (or indeed me with mine) can deduce.

I am looking forward to reading about the measurements you have commissioned.

Come on Micro Audio ... add some more power and noise measurements to your documentation ... and make them "ASR proof"!!

 

[daniboun]

Yes I read this, but you have made the comparison in terms of measurement analysis between the Stereophile review vs the Morsun.

Instead I think that we need the manufacturers to give measurements ... and for ASR to hold them to their measurements ... and then you with your listening (or indeed me with mine) can deduce.

I am looking forward to reading about the measurements you have commissioned.

Come on Micro Audio ... add some more power and noise measurements to your documentation ... and make them "ASR proof"!!

This is exactly why I called on this German lab)
Let's wait until the end of the month and we'll see what the tests say)

In full transparency, I spoke with Micro Audio to see if we could agree to the design of a "Micro Bamboo V2" project with an SMPS630 REV2 PSU. The idea always remains the same, to be able to measure this new project with an Apx555. )))

I will keep you all posted about this new project.

 

[rsqt]

Hello daniboun,

you said you will test some further capacitance. Will you take many smaller caps or only a few bigger? Years ago I tried this with a class d amp with 6x10000uF and for my ears the bass was more precise and sound overall was smoother.

 

[daniboun]

Hi amigos,

Got the LLC / PFC 600W + Soft Start PSU
Size 184*88*43mm
Weight: 0.43KG
(ouput caps are rated @ 2 x 2200uf / 63V)

Here some pictures so you can have an idea.
I measured 48VDC @ Multimeter and stable (voltage range 45-50V)

The + :

- LLC independent circuit
- Active PFC (PFC power factor: 0.961)
- Soft Start module

The - :
- Not necessary a small factor PSU

I think it's difficult to do better at this price)

 

[daniboun]

Hello daniboun,

you said you will test some further capacitance. Will you take many smaller caps or only a few bigger? Years ago I tried this with a class d amp with 6x10000uF and for my ears the bass was more precise and sound overall was smoother.

I received the Connex extra caps module but they sent me the wrong model.... Wont be able to test this board. Need to ship it back ((( Anyway the extra caps are not necessary fot BTL modules as discussed.

 

[Tell]

Hi amigos,

Got the LLC / PFC 600W + Soft Start PSU
Size 184*88*43mm
Weight: 0.43KG
(ouput caps are rated @ 2 x 2200uf / 63V)

Here some pictures so you can have an idea.
I measured 48VDC @ Multimeter and stable (voltage range 45-50V)

The + :

- LLC independent circuit
- Active PFC (PFC power factor: 0.961)
- Soft Start module

The - :
- Not necessary a small factor PSU

I think it's difficult to do better at this price)


View attachment 360164View attachment 360165
View attachment 360166View attachment 360167
View attachment 360170

This looks interesting! But how big of a difference is there really between PSUs? I mean in their power delivery? And their longevity?
Personally I have a Connex SMPS500r that I bought eight years ago to drive a pair of IRS2092 amps but I recently noticed that the capacitors had started to swell, giving me high pitched noises from my speakers. I thought that Connex made high quality stuff, but apparently not.
Feels like it's really hard two know, so you just have to take a chance and then some years later you might know if it was good or bad.

 

[daniboun]

This looks interesting! But how big of a difference is there really between PSUs? I mean in their power delivery? And their longevity?
Personally I have a Connex SMPS500r that I bought eight years ago to drive a pair of IRS2092 amps but I recently noticed that the capacitors had started to swell, giving me high pitched noises from my speakers. I thought that Connex made high quality stuff, but apparently not.
Feels like it's really hard two know, so you just have to take a chance and then some years later you might know if it was good or bad.

Time will tell... But to find out you have to test)
In the meantime, if I just had to rely on the visuals, the Micro Audio stands out from the crowd.

 

[daniboun]

Hi amigos,

Here the new revision of the 3E Audio 260-2-29A / 480-1-29A

 

[daniboun]

Waiting for the Micro Audio SO630 REV2 PSU. I had fun imagining an integration with my other YZX 600W LLC/PFC PSU and the Connex LPS212A module + 3E Audio Rev 2 Stereo