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

[Treborha]

I just turned on my amplifier. Remote volume control will also be included. Plays great

 

[timiambeing]

I must admit that there is some truth in what you say) On the other hand, if we distinguish between DIY and those Chinese RTR amplifiers, the clear advantage of DIY amps is to offer a qualitative kit. Fosi, Aiyima etc. amps are supplied with low-end brick type PSUs. Not to mention the internal wiring and the sacrifice made on a few other points...
We will see at what price the Fosi and the Aiyima will be offered with a PFFB implementation...But they won't have invented anything since Topping already offered RTR PFFB amps a long time ago....

Personally I would have more confidence with my Bamboo projects rather than a Fosi amp or other, especially since I control what I put in my amps.
I would have a hard time comparing a Fosi or Aiyima to a DIY with a Micro-Audio PSU for example.... but we all agree on one point: quality has to be paid for at some point. --)

It’s funny but I would have thought, bearing in mind the solid build if the ICEPower, my confidence in its provenance and how well it measures, that it would have trounced the Fosi easily! I expected it to, I wanted it to, but in careful, long term listening tests it clearly didn’t. Which I’m pleased about really as some folk would have us believe our own perception is not at all to be trusted, whereas these old audiophile ears proved reliable after all - totally in opposition to all the biases in play! Bugger really!

PS: it’s funny in my main system I have an esoteric no doubt coloured ladder DAC feeding a class D clean as you like amp, and it sound amazing… in my headphone system I have lovely warm class A amp being fed by a clean, clear and amazingly well measuring Chinese DAC, and it sounds amazing… I’m learning new stuff everyday!

 

[daniboun]

It’s funny but I would have thought, bearing in mind the solid build if the ICEPower, my confidence in its provenance and how well it measures, that it would have trounced the Fosi easily! I expected it to, I wanted it to, but in careful, long term listening tests it clearly didn’t. Which I’m pleased about really as some folk would have us believe our own perception is not at all to be trusted, whereas these old audiophile ears proved reliable after all - totally in opposition to all the biases in play! Bugger really!

PS: it’s funny in my main system I have an esoteric no doubt coloured ladder DAC feeding a class D clean as you like amp, and it sound amazing… in my headphone system I have lovely warm class A amp being fed by a clean, clear and amazingly well measuring Chinese DAC, and it sounds amazing… I’m learning new stuff everyday!

Could please share a link to your Icepower amp ? The same for your DAC please ?
If you refer to the IcePower 125ASX2, I would say that it is not very difficult to do better.... Its FFT says a lot with a notable imbalance / mismatch between the two channels
Threshold of hearing also increases with frequency above 5 kHz for the Icepower.
The Fosi shows a big load impedance dependency......

For me, these are two fairly mediocre amps if we compare them to a TPA325X with a PFFB implementation worthy of the name)

 

[timiambeing]

For me, these are two fairly mediocre amps if we compare them to a TPA325X with a PFFB implementation worthy of the name)

Ah! Then I only have good things to look forward too! I have the Fosi V3 not the newer one just released, although I suspect it is very similar in specs. My DAC is this one, only not the 12th, it’s the Pontus II - I did do a bit of digging and somewhere I read this has a high frequency dependent output impedance, probably not ideal for ICEPower amps do you think? The kit I made was this one…

 

[daniboun]

Ah! Then I only have good things to look forward too! I have the Fosi V3 not the newer one just released, although I suspect it is very similar in specs. My DAC is this one, only not the 12th, it’s the Pontus II - I did do a bit of digging and somewhere I read this has a high frequency dependent output impedance, probably not ideal for ICEPower amps do you think? The kit I made was this one…

The Denafrips Pontus II is based on two FPGAs, this is a R2R DAC.
Unfortunately this DAC is not good at all.... Even a $140 DAC like the Topping E30 II measures better than this Denafrips...
On the Sinad ASR list, it would be placed in the “Poor” category. that is a real shame for a $2200 dac

Once again, don't trust your ears... they are truncated instruments and will often deceive you.

Here some APX555 B-Series measurements :

 

[CamRector]

Just wanted to say to anyone on the fence about these amps. Do it! And use a micro audio power supply. My 4 channel
sounds amazing. Clean, neutral, precise. Not analytical or cold at all!
This is high end

 

[timiambeing]

The Denafrips Pontus II is based on two FPGAs, this is a R2R DAC.
Unfortunately this DAC is not good at all.... Even a $140 DAC like the Topping E30 II measures better than this Denafrips...
On the Sinad ASR list, it would be placed in the “Poor” category. that is a real shame for a $2200 dac

Once again, don't trust your ears... they are truncated instruments and will often deceive you.

Here some APX555 B-Series measurements :


View attachment 350038
View attachment 350039
View attachment 350040

I understand the viewpoint of those in fascination with measurements, and indeed if measurements were the only indicator of sound reproduction I would have to agree with you… but they are most definitely not. It’s fine you have a firm belief in measurement as the best way to asses fidelity, and I enjoy the technical details derived by reviews here on ASR - they do indeed confirm what goes in is actually what comes out in some parameters. However, over many years of experience of listening to hundreds of pieces of audio equipment in combination with each other, I can happily confirm that how a component actually sounds has often very little to do with how it measures - except in the extreme of course.

And I think that is the point here, listening. You have a firm opinion you can’t trust your ears, that your biases will rule and your brain will lie to you. I on the other hand have exactly the opposite opinion. After so many years of experience of falling for biases they no longer concern me, if a cello sounds more like a cello with one DAC rather than another in my system, then the DAC with the most convincing approximation of reality is always my choice. I don’t care if it measures like an old sewing machine, it’s how it sounds that matters - because isn’t that how we enjoy our music, with our ears?

Just as you are convinced that ears are the last thing to trust, and so that is your reality and I respect that, I am absolutely sure that I can trust mine - because really, even if they lied to me, I would be in heaven listening to their subterfuge!

 

[CamRector]

Fosi and Aiyima aren’t going to be able to touch DIY. My 4 channel has 4 caps that cost more than the highest offering these companies offer.
The Fosi power supply costs $40
This doesn’t come anywhere near the level of quality of the Micro Audio smps.
There is always a market for Hyundai but I prefer the BMW.

 

[bugal]

"Once again, don't trust your ears... they are truncated instruments and will often deceive you."

On the AUDIOsciencereview forum It sounds like a call for anarchy/revolution

I believe that the main purpose of any audio gears is to satisfy our ears, so we have to trust them anyway (or first of all).

One man can enjoy listening to music using their ears (e.g. interested in authenticity of musical instrument's sound/feel, soundstage depth/width, instrument placement, etc.) and the other one does not trust their ears while listening to music and is happy and comfortable just becuase their equipment is listed on top charts of the results/specs reviews.

 

[Ordin Aryguy]

My 4 channel has 4 caps that cost more than the highest offering these companies offer.

Ok, I'll bite...

What measurable characteristics about caps that cost 4X more $ make them actually demonstrably better?
ESL?
ESR?
Temp Coefficient?
Voltage Coefficient?
Something else?
Just saying they sound better isn't an answer.

Capacitors seem to be the new cables. Spend lots of $ on boutique components without actually knowing why.

 

[CamRector]

Ok, I'll bite...

What measurable characteristics about caps that cost 4X more $ make them actually demonstrably better?
ESL?
ESR?
Temp Coefficient?
Voltage Coefficient?
Something else?
Just saying they sound better isn't an answer.

Capacitors seem to be the new cables. Spend lots of $ on boutique components without actually knowing why.

I never said the caps make them “sound better”.
My point was that they are a higher quality and made to tighter tolerances than what cheap components Fosi and Aiyima have to use. Cheap caps fail.
However large capacitance decreases the audio circuit's impedance, limiting the amount of noise between the power supply and the actual audio driving circuitry. So in my case 40000 extra uf is doing a lot more than a Fosi will be able to.

 

[Ordin Aryguy]

I never said the caps make them “sound better”.
My point was that they are a higher quality and made to tighter tolerances than what cheap components Fosi and Aiyima have to use. Cheap caps fail.
However large capacitance decreases the audio circuit's impedance, limiting the amount of noise between the power supply and the actual audio driving circuitry. So in my case 40000 extra uf is doing a lot more than a Fosi will be able to.

Forty years of engineering behind me now, and I am admittedly far from being an expert, but I will claim to have been exposed to a little more than "the average bear."

Capacitors absolutely have become the new darling drug component of choice, now that most have accepted the cable tomfoolery as bunk.

It's likely because capacitors have more "moving parts" and they really do play an active part in circuits and systems, making them a bit more of a mystery. Cables, not so much.

Do ultrasound machines, radar transceivers, satellite radios, or any other ultrasensitive electronic systems such as those have boutique capacitors in them? Nope. They're using Cornell-Doubilier, AVX, Kemet, Nichicon, Panasonic, etc. capacitors. The boutique capacitor companies are fleecing the sheep just like the boutique cable companies do.

Because some folks have found that electrolytic capacitors (caps with wet electrolytes) have their performance seriously degrade over time as the electrolyte fails, there is a belief that boutique capacitors are the only answer. Pure silliness.

I'll leave my comments here and not continue, as I don't want to take away from the OP's intent with this thread.

EDIT: Adding a link to a post I recently did on another thread about adding additional capacitance on power supply rails... and this is just barely scratching the surface, but is relevant in that you said you added 40,000 uf extra.

'Headroom' is a measure of the badness of an amplifier. The bigger the number, the worse the amplifier.

Then let us perform a mind experiment. You can not even be bothered to define what exactly would be "better" And how this "better" would measure. You seam to think more power is better? Then how and why is it better to have less "Headroom"? Sure an amp with more continues Power can be called...

www.audiosciencereview.com

 

[CamRector]

Forty years of engineering behind me now, and I am admittedly far from being an expert, but I will claim to have been exposed to a little more than "the average bear."

Capacitors absolutely have become the new darling drug component of choice, now that most have accepted the cable tomfoolery as bunk.

It's likely because capacitors have more "moving parts" and they really do play an active part in circuits and systems, making them a bit more of a mystery. Cables, not so much.

Do ultrasound machines, radar transceivers, satellite radios, or any other ultrasensitive electronic systems such as those have boutique capacitors in them? Nope. They're using Cornell-Doubilier, AVX, Kemet, Nichicon, Panasonic, etc. capacitors. The boutique capacitor companies are fleecing the sheep just like the boutique cable companies do.

Because some folks have found that electrolytic capacitors (caps with wet electrolytes) have their performance seriously degrade over time as the electrolyte fails, there is a belief that boutique capacitors are the only answer. Pure silliness.

I'll leave my comments here and not continue, as I don't want to take away from the OP's intent with this thread.

Cool story
40 years of “experience” surely taught you can add extra capacitors to attenuate undesired electrical noise to the external load and minimize the change in output voltage due to the occurrence of load current transients.

 

[CamRector]

Forty years of engineering behind me now, and I am admittedly far from being an expert, but I will claim to have been exposed to a little more than "the average bear."

Capacitors absolutely have become the new darling drug component of choice, now that most have accepted the cable tomfoolery as bunk.

It's likely because capacitors have more "moving parts" and they really do play an active part in circuits and systems, making them a bit more of a mystery. Cables, not so much.

Do ultrasound machines, radar transceivers, satellite radios, or any other ultrasensitive electronic systems such as those have boutique capacitors in them? Nope. They're using Cornell-Doubilier, AVX, Kemet, Nichicon, Panasonic, etc. capacitors. The boutique capacitor companies are fleecing the sheep just like the boutique cable companies do.

Because some folks have found that electrolytic capacitors (caps with wet electrolytes) have their performance seriously degrade over time as the electrolyte fails, there is a belief that boutique capacitors are the only answer. Pure silliness.

I'll leave my comments here and not continue, as I don't want to take away from the OP's intent with this thread.

EDIT: Adding a link to a post I recently did on another thread about adding additional capacitance on power supply rails... and this is just barely scratching the surface, but is relevant in that you said you added 40,000 uf extra.

'Headroom' is a measure of the badness of an amplifier. The bigger the number, the worse the amplifier.

Then let us perform a mind experiment. You can not even be bothered to define what exactly would be "better" And how this "better" would measure. You seam to think more power is better? Then how and why is it better to have less "Headroom"? Sure an amp with more continues Power can be called...

www.audiosciencereview.com

Responding to your edit.
You seem to be putting a lot of words in my mouth and assuming.
Firstly the Micro is an unregulated SMPS.
Secondly Noise is a problem with ALL switching supplies, but is solvable by physically isolating and ……filtering the supply (Ahem LARGE CAPS!)
But Fosi and Aiyima can’t really do this because the……. particularly larger electrolytic capacitors, are expensive and every engineer is burdened with the COG's (Cost of Goods) challenge.
I’m not burdened.

 

[cfwotzka]

I understand the viewpoint of those in fascination with measurements, and indeed if measurements were the only indicator of sound reproduction I would have to agree with you… but they are most definitely not. It’s fine you have a firm belief in measurement as the best way to asses fidelity, and I enjoy the technical details derived by reviews here on ASR - they do indeed confirm what goes in is actually what comes out in some parameters. However, over many years of experience of listening to hundreds of pieces of audio equipment in combination with each other, I can happily confirm that how a component actually sounds has often very little to do with how it measures - except in the extreme of course.

And I think that is the point here, listening. You have a firm opinion you can’t trust your ears, that your biases will rule and your brain will lie to you. I on the other hand have exactly the opposite opinion. After so many years of experience of falling for biases they no longer concern me, if a cello sounds more like a cello with one DAC rather than another in my system, then the DAC with the most convincing approximation of reality is always my choice. I don’t care if it measures like an old sewing machine, it’s how it sounds that matters - because isn’t that how we enjoy our music, with our ears?

Just as you are convinced that ears are the last thing to trust, and so that is your reality and I respect that, I am absolutely sure that I can trust mine - because really, even if they lied to me, I would be in heaven listening to their subterfuge!

My philosophy: Good measurement results show the direction, individual listening finds the goal. In other words, both are needed to achieve an individually convincing result.

 

[daniboun]

I understand the viewpoint of those in fascination with measurements, and indeed if measurements were the only indicator of sound reproduction I would have to agree with you… but they are most definitely not. It’s fine you have a firm belief in measurement as the best way to asses fidelity, and I enjoy the technical details derived by reviews here on ASR - they do indeed confirm what goes in is actually what comes out in some parameters. However, over many years of experience of listening to hundreds of pieces of audio equipment in combination with each other, I can happily confirm that how a component actually sounds has often very little to do with how it measures - except in the extreme of course.

And I think that is the point here, listening. You have a firm opinion you can’t trust your ears, that your biases will rule and your brain will lie to you. I on the other hand have exactly the opposite opinion. After so many years of experience of falling for biases they no longer concern me, if a cello sounds more like a cello with one DAC rather than another in my system, then the DAC with the most convincing approximation of reality is always my choice. I don’t care if it measures like an old sewing machine, it’s how it sounds that matters - because isn’t that how we enjoy our music, with our ears?

Just as you are convinced that ears are the last thing to trust, and so that is your reality and I respect that, I am absolutely sure that I can trust mine - because really, even if they lied to me, I would be in heaven listening to their subterfuge!

It's an eternal debate here... But keep in mind that we are on a forum based on scientific evidence. If Amir shares such reviews it is precisely to avoid spending astronomical sums on products that do not measure well.
Questioning the measurements is in a way denying science... If you are convinced that the dythirambic poems that we see on the Stereophile, What Hifi etc. reviews can comfort your ears, then run away from home ASR.

I don't think many people would buy a DAC that measures poorly at $2200? I am also not convinced that you would have bought it if you had read the measurements beforehand....

But as you say, everyone has their own reality) I have been a musician myself for several years but my ears have often deceived me and ASR remains an undeniable basis in my audio choices. -)))

 

[daniboun]

Ok, I'll bite...

What measurable characteristics about caps that cost 4X more $ make them actually demonstrably better?
ESL?
ESR?
Temp Coefficient?
Voltage Coefficient?
Something else?
Just saying they sound better isn't an answer.

Capacitors seem to be the new cables. Spend lots of $ on boutique components without actually knowing why.

Only measurements matter here I agree. The proof by A+B:

Audible difference in high-end capacitors? - ABX samples

As announced long ago the last part on the subject of audibility of capacitor upgrade in crossovers. The comparison ranges from a very cheap, decades-old film capacitor to an expensive high-end capacitor. As promised, this time there are short audio samples of each capacitor (in a simple...

www.audiosciencereview.com

 

[daniboun]

On the AUDIOsciencereview forum It sounds like a call for anarchy/revolution

If measurements and scientific evidence bother you, why come here then?
I don't see any revolution in @amirm 's reviews... These are pragmatic tests that simply help you optimize your choices.
You have the right to enjoy music as you see fit, that's not the debate here. As its name suggests, Audio Science Review is a site based on science and not subjectivity.

 

[CamRector]

Only measurements matter here I agree. The proof by A+B:

Audible difference in high-end capacitors? - ABX samples

As announced long ago the last part on the subject of audibility of capacitor upgrade in crossovers. The comparison ranges from a very cheap, decades-old film capacitor to an expensive high-end capacitor. As promised, this time there are short audio samples of each capacitor (in a simple...

www.audiosciencereview.com

You both seem to think I said something about audiophile caps “sounding” better than some other type of cap.
I made no such claim so please stop putting words in my mouth.
The audible difference between adding more/larger caps would come from a reduction of noise by filtering.
Similar to all the ferrite tubes/emi/rfi filters you add to all your amps @daniboun
Cheaper Aiyima and Fosi amps do not have more/larger caps due to cost.
They have some cheap external brick psu that doesn’t come close to the quality of a Micro Audio

 

[bugal]

If measurements and scientific evidence bother you, why come here then?
I don't see any revolution in @amirm 's reviews... These are pragmatic tests that simply help you optimize your choices.
You have the right to enjoy music as you see fit, that's not the debate here. As its name suggests, Audio Science Review is a site based on science and not subjectivity.

"Do not trust your ears" - that's what bothers me in fact. And not Amir's measurements and reviews.
They are a great help however they shoud be percived like a guide or map to bulid a cohesive and well-ballanced audio system.
Enjoing the SINAD scores alone without inviting one's ears for the sound impression judgment (or final buying decision) sounds really unconvincing in the audio world. At least for me.