• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

"Bamboo V2" project. 3E Audio 260-2-29A Stéréo Rev. B (OPA1656) + PFC/LLC PSU. APx555 Measurements )

daniboun

Major Contributor
Joined
May 2, 2020
Messages
1,955
Likes
2,336
Location
France (Lyon)
Hi amigos,

Before starting, I suspended the measurements of the first project "Micro Bamboo." I will come back to the quick measurements at the end of May finally, I still have to speak with Sami about his Micro Audio PSU... am focusing on this thread only on the measures of the "Bamboo V2" project which highlights revision B of the 3E Audio module 260-2-29A and a brand new PSU that I found on the web)

This is my very first experience with measurements, by which I mean entrusting a project to a professional with an APx555. I would therefore like to point out that I am not an expert in this field and my knowledge is therefore still limited even if I love learning)
I won't hide from you that I had a sinking feeling in my stomach when I shipped my amps to the German lab. First I was afraid that it would go wrong and I admit that I have little confidence in the carriers (we use “Colissimo”, the French post office in France). I was also apprehensive about the results of the measurements since I had absolutely no knowledge of this German Lab before. I was also apprehensive about the results of the measurements since I discovered this German Lab by chance.

But then who is behind this lab? It is in fact in its official name Dr-Jordan-Design whose owner is Frank). He is based in Dresden (for those who know the duo band “Dresden Dolls” which I love by the way!) I entrusted this measurement project to Frank because it is the only lab I found in Europe which has an APx555 and which offers these measurements as a service. You will understand that French laws regarding exports and shipping outside Europe are so expensive and complicated; that I had to find an ASR equivalence in Europe....

About @docjordan :
"My name is Frank Jordan, located in Germany, Dresden. Most people call me ‘docjordan’, simply because I studied electrical engineering in Hamburg and I have PhD on communication systems. My professional work with audio started mid 1990s. In 2000 I finished my PhD on digital communication systems.
From a first sight this has nothing to do with audio, but the research work on signal processing was very useful for audio. Look e.g. at audio compression techniques like mp3, or the STI measurement method
In general, I cover all range of audio starting with infra-sound up to ultra-sonic, room- and building acoustics and psycho-acoustics. Special focus is on ISO/IEC/DIN compliant measurements.
Most of my work is software development using most of modern languages. Focus is DSP and audio measurements.


I own a very well-equipped lab for audio and acoustic measurement including all premium brand tools. This includes an APX555 which is the heart of my measurements. As a special, I did deep reverse engineering of the APX-Framework and offer independent plugins for special measurements. I have a good communication loop with AP (Greetings to Dan Knighten), but there is no business interaction (although I enjoy working with their products), I’m working 100% independent.

Since 2002, I own a small business called “Dr-Jordan-Design”.

www.akustik-messen.de
www.akulap.de (webshop)

My focus is audio measurements, from software, microphones to turnkey solutions.
I engineer professional audio measurement systems. In addition to my core product (Akulap), a software based real-time analyzer, I offer turn-key solutions including all hardware (calibrators, interfaces, microphones, loudspeakers, sound level meters etc.).
I cover a wide range of applications e.g. room acoustics, building acoustics, long-term sound monitoring, production tests and my special focus is psycho-acoustics and many more
I develop stand-alone software e.g. Akulap and plugins for the APX audio analyzer series from Audio Precision
In addition, I offer full custom solutions in the area of measurement and digital signal processing.
For non-commercial applications and education facilities I offer my software products at special conditions.
Due to my large experience for many years, I offer measurements as a service."



I also wanted to take advantage of this thread to thank several members :

@docjordan > Many thanks for your professionalism and patience!
@SylphAudio > you have superb knowledge thank you!
@antcollinet > I think you are an excellent theoretician, thank you for your help.
@oal > I loved your review of the SylphD100, it inspired me a lot
@3eaudio > Your modules are excellent, continue to develop them)
@MicroAudio > Thank you for your collaboration


1714400623048.png
1714400650339.png

1714400680347.png
1714400714633.png

1714400781613.png
1714400905369.png




Test protocol:

Audio Analyser 1 : APx555 + Passive filter (Aux-0025)
Default filter : AES17 20Khz.


Amplifier: Bamboo V2
3E Audio 260-2-29A Stéréo REB B (OPA1656)
PSU : Yongzhuxing 600W PFC /LLC @48V
Extra Caps module Connex LPS212A (4X 4700uf)

Before going on, I would like to point out that Frank measured the Aiyima A07 and his results agree with those of Amir. Which is a guarantee of consistency)
Please note that the measurements were carried out with the Extra caps Connex module.


Let’s start with the first usual dashboard :

1714401151999.png


1714401174338.png


1714401210014.png


1714401275506.png


1714401311150.png


1714401359453.png


1714401399396.png


1714401431377.png



1714401560434.png


1714401588245.png


Conclusion :

It is interesting to note that the PSU may have a slight impact on the Sinad.
This Rev B of the 3E Audio 260-2-29A Module remains faithful to the performances measured on the Rev A. The addition of an Extra caps module does not provide anything very convincing. Performance is excellent considering the overall value for money.
Subjective listening : It's almost impossible to hear the difference between revision A and B of the 3E Audio module... My HD playlist sounds very good with both configurations)
For those who wish to embark on such a project, do not hesitate to ask me for advice, it will always be a pleasure)
 

Attachments

  • 1714400812520.png
    1714400812520.png
    1.3 MB · Views: 99
  • 1714400855897.png
    1714400855897.png
    1 MB · Views: 98
  • 1714401480968.png
    1714401480968.png
    82.8 KB · Views: 106
  • 1714401771072.png
    1714401771072.png
    962.5 KB · Views: 102

olieb

Senior Member
Joined
Jul 1, 2023
Messages
379
Likes
618
Thanks for the cool project and the first rate measurements.
I wonder about the PSU from Yongzhuxing. I am rather clueless about switching PSUs but looking on aliexpress there seem to be dozens of similar ones. What made you pick this one?
After seeing these results which one would you recommend? Connex, Mornsun, Yongzhuxing, other ...?
 

Guddu

Major Contributor
Joined
Feb 10, 2020
Messages
1,032
Likes
921
Hi amigos,

Before starting, I suspended the measurements of the first project "Micro Bamboo." I will come back to the quick measurements at the end of May finally, I still have to speak with Sami about his Micro Audio PSU... am focusing on this thread only on the measures of the "Bamboo V2" project which highlights revision B of the 3E Audio module 260-2-29A and a brand new PSU that I found on the web)

This is my very first experience with measurements, by which I mean entrusting a project to a professional with an APx555. I would therefore like to point out that I am not an expert in this field and my knowledge is therefore still limited even if I love learning)
I won't hide from you that I had a sinking feeling in my stomach when I shipped my amps to the German lab. First I was afraid that it would go wrong and I admit that I have little confidence in the carriers (we use “Colissimo”, the French post office in France). I was also apprehensive about the results of the measurements since I had absolutely no knowledge of this German Lab before. I was also apprehensive about the results of the measurements since I discovered this German Lab by chance.

But then who is behind this lab? It is in fact in its official name Dr-Jordan-Design whose owner is Frank). He is based in Dresden (for those who know the duo band “Dresden Dolls” which I love by the way!) I entrusted this measurement project to Frank because it is the only lab I found in Europe which has an APx555 and which offers these measurements as a service. You will understand that French laws regarding exports and shipping outside Europe are so expensive and complicated; that I had to find an ASR equivalence in Europe....

About @docjordan :
"My name is Frank Jordan, located in Germany, Dresden. Most people call me ‘docjordan’, simply because I studied electrical engineering in Hamburg and I have PhD on communication systems. My professional work with audio started mid 1990s. In 2000 I finished my PhD on digital communication systems.
From a first sight this has nothing to do with audio, but the research work on signal processing was very useful for audio. Look e.g. at audio compression techniques like mp3, or the STI measurement method
In general, I cover all range of audio starting with infra-sound up to ultra-sonic, room- and building acoustics and psycho-acoustics. Special focus is on ISO/IEC/DIN compliant measurements.
Most of my work is software development using most of modern languages. Focus is DSP and audio measurements.


I own a very well-equipped lab for audio and acoustic measurement including all premium brand tools. This includes an APX555 which is the heart of my measurements. As a special, I did deep reverse engineering of the APX-Framework and offer independent plugins for special measurements. I have a good communication loop with AP (Greetings to Dan Knighten), but there is no business interaction (although I enjoy working with their products), I’m working 100% independent.

Since 2002, I own a small business called “Dr-Jordan-Design”.

www.akustik-messen.de
www.akulap.de (webshop)

My focus is audio measurements, from software, microphones to turnkey solutions.
I engineer professional audio measurement systems. In addition to my core product (Akulap), a software based real-time analyzer, I offer turn-key solutions including all hardware (calibrators, interfaces, microphones, loudspeakers, sound level meters etc.).
I cover a wide range of applications e.g. room acoustics, building acoustics, long-term sound monitoring, production tests and my special focus is psycho-acoustics and many more
I develop stand-alone software e.g. Akulap and plugins for the APX audio analyzer series from Audio Precision
In addition, I offer full custom solutions in the area of measurement and digital signal processing.
For non-commercial applications and education facilities I offer my software products at special conditions.
Due to my large experience for many years, I offer measurements as a service."



I also wanted to take advantage of this thread to thank several members :

@docjordan > Many thanks for your professionalism and patience!
@SylphAudio > you have superb knowledge thank you!
@antcollinet > I think you are an excellent theoretician, thank you for your help.
@oal > I loved your review of the SylphD100, it inspired me a lot
@3eaudio > Your modules are excellent, continue to develop them)
@MicroAudio > Thank you for your collaboration


View attachment 366649View attachment 366650
View attachment 366651View attachment 366652
View attachment 366653View attachment 366656



Test protocol:

Audio Analyser 1 : APx555 + Passive filter (Aux-0025)
Default filter : AES17 20Khz.


Amplifier: Bamboo V2
3E Audio 260-2-29A Stéréo REB B (OPA1656)
PSU : Yongzhuxing 600W PFC /LLC @48V
Extra Caps module Connex LPS212A (4X 4700uf)

Before going on, I would like to point out that Frank measured the Aiyima A07 and his results agree with those of Amir. Which is a guarantee of consistency)
Please note that the measurements were carried out with the Extra caps Connex module.


Let’s start with the first usual dashboard :

View attachment 366657

View attachment 366658

View attachment 366659

View attachment 366660

View attachment 366661

View attachment 366662

View attachment 366663

View attachment 366664


View attachment 366666

View attachment 366667

Conclusion :

It is interesting to note that the PSU may have a slight impact on the Sinad.
This Rev B of the 3E Audio 260-2-29A Module remains faithful to the performances measured on the Rev A. The addition of an Extra caps module does not provide anything very convincing. Performance is excellent considering the overall value for money.
Subjective listening : It's almost impossible to hear the difference between revision A and B of the 3E Audio module... My HD playlist sounds very good with both configurations)
For those who wish to embark on such a project, do not hesitate to ask me for advice, it will always be a pleasure)
@daniboun Nothing short of amazing.
 
OP
daniboun

daniboun

Major Contributor
Joined
May 2, 2020
Messages
1,955
Likes
2,336
Location
France (Lyon)
OP
daniboun

daniboun

Major Contributor
Joined
May 2, 2020
Messages
1,955
Likes
2,336
Location
France (Lyon)
Thanks for the cool project and the first rate measurements.
I wonder about the PSU from Yongzhuxing. I am rather clueless about switching PSUs but looking on aliexpress there seem to be dozens of similar ones. What made you pick this one?
After seeing these results which one would you recommend? Connex, Mornsun, Yongzhuxing, other ...?

Well I tested a bunch of PSUs and I admit that the comments on this PSU were rather positive... so I gave it a go. At this price, difficult to find a 600W PSU which combines two independent circuits for the LLC and PFC part and what's more, provides a Soft start
 
Last edited:

olieb

Senior Member
Joined
Jul 1, 2023
Messages
379
Likes
618
Yes it was a compliment, a strong one indeed. I assume you are not a native English speaker so https://www.collinsdictionary.com/dictionary/english/nothing-short-of
Whenever I am not certain what exactly is the meaning of something I use deepl.com . In most cases it actually helps me.
Here is the output in this case:
@daniboun Rien de moins qu'étonnant.
@daniboun Nada menos que incrível.
Well I tested a bunch of PSUs and I admit that the comments on this PSU were rather positive... so I gave it a go. At this price, difficult to find a 600W PSU which combines two independent circuits for the LLC and PFC part and what's more, combines a Soft start
Thank you.
As mentioned I do not know about the advantages of these independent circuits but soft start that at least I get ;-)
 
OP
daniboun

daniboun

Major Contributor
Joined
May 2, 2020
Messages
1,955
Likes
2,336
Location
France (Lyon)
Chaque fois que je ne suis pas sûr de la signification exacte de quelque chose, j'utilise deepl.com. Dans la plupart des cas, cela m'aide réellement.

The translation gave me "rien d incroyable" which is not a compliment in French lol
In any case I would have learned something))
 
OP
daniboun

daniboun

Major Contributor
Joined
May 2, 2020
Messages
1,955
Likes
2,336
Location
France (Lyon)
Thank you.
As mentioned I do not know about the advantages of these independent circuits but soft start that at least I get ;-)

I would especially say that for 50 € we are not taking too much risk.... Knowing that the Morsun is worth double and that the Micro Audio even more....
 

brunes

Active Member
Joined
Jun 7, 2023
Messages
125
Likes
143
Love the effort you put in here!
Interesting to see minimal if any difference between the 3e V1 and V2.
I understand the power supply you used has PFC, really curious what - if anything the MicroAudio will produce in terms of numbers..
 

SMen

Active Member
Joined
Jan 2, 2022
Messages
225
Likes
111
Thanks for the cool project and the first rate measurements.
I wonder about the PSU from Yongzhuxing. I am rather clueless about switching PSUs but looking on aliexpress there seem to be dozens of similar ones. What made you pick this one?
After seeing these results which one would you recommend? Connex, Mornsun, Yongzhuxing, other ...?
Yes please expand on this with links. Great project thank you.
 

Sokel

Master Contributor
Joined
Sep 8, 2021
Messages
6,522
Likes
6,714
The extra caps bank is usually used with hypex to help down low.
A power vs distortion measurement could be helpful comparing with and without it.
 
OP
daniboun

daniboun

Major Contributor
Joined
May 2, 2020
Messages
1,955
Likes
2,336
Location
France (Lyon)
Love the effort you put in here!
Interesting to see minimal if any difference between the 3e V1 and V2.
I understand the power supply you used has PFC, really curious what - if anything the MicroAudio will produce in terms of numbers..

I will share quick measurements by the end of the month on the "Micro Bamboo" thread so that you can understand the influence of the PSU on performance.
 

V.b.

Member
Joined
Mar 8, 2021
Messages
57
Likes
51
The extra caps bank is usually used with hypex to help down low.
A power vs distortion measurement could be helpful comparing with and without it.
Or a peak power measurement at 1% THD
 
OP
daniboun

daniboun

Major Contributor
Joined
May 2, 2020
Messages
1,955
Likes
2,336
Location
France (Lyon)
Or a peak power measurement at 1% THD

Extra caps are of little interest for BTL / PBTL type amps
Good explanation by @SylphAudio >

"Bus pumping is aggravated on class-D amplifiers with single ended outputs. One of the mitigation techniques include placing large bus capacitors to absorb the energy backflow from the load to the power supply. If the energy backflows, then it will "pump up" the supply rail voltage (if the supply can't regulate it properly).
Like our upcoming SE800 amplifier, it has a single ended output, which requires an external 6800uF per rail to avoid bus pumping.
By having the class-d on BTL (full bridge) configuration, it will balance out the energy flow, so it's a non-issue on BTL amps. So, large caps are not required for TPA325x amps."
 
Joined
Sep 2, 2023
Messages
7
Likes
0
Do you think it's possible this project (or similar with the 3E board) could fit in a 1U rack chassis?
I just got mine and still deciding on a PSU, etc.

Also was curious about something as a noob, since I see 12v triggers and soft start power supplies pretty commonly…
I know speakers popping is bad, which is why I use a power sequencer, but would there be an issue with leaving the amp switched on but pulling power?
 
Last edited:
Top Bottom