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

[brunes]

To help, Hypex recommendations :
I would ground both PSUs to same point.

View attachment 345532

This is useful thanks.
So... Pin1 XLR to chasis with the XLR tab.
So you ground the 3e audio amp to the case using this cable set connected to the chasis...

And IEC and SMPS to case also via. common SP.
I think that's clear.

I also read this:
In the case of an amplifier, say, especially one with balanced inputs, XLR pin 1 should always just go directly to the chassis and nowhere else. Signal ground can be connected directly to the chassis somewhere else in the box, can be connected to the chassis through a resistor, say 10-100 ohms, can be connected to the chassis through a low value capacitor and or the resistor, or indeed left floating

 

[brunes]

ok got it.. found this earlier thread... it should all go to star ground (but not to pin 1-which should only go to chasis)

 

[CamRector]

Fin.

 

[daniboun]

ok got it.. found this earlier thread... it should all go to star ground (but not to pin 1-which should only go to chasis)

Nice you checked the answer from the earlier Thread )
With the help of @S=klogW we carried out measurements between compliance with the AES standard for cabling and current practice

The AES48 method recommends this :

BUT The measurements show no difference between the old practice and AES standard :

Source : https://audiosciencereview.com/foru...ft-pffb-fully-differential.47660/post-1717825


3E Audio Module wired with AES48 Method

3E Audio Module wired with old practice :

 

[brunes]

Good to know! So is everyone connecting the ground from the 3e amp to pin 1 (jst connector) AND the xlr tab to the chasis? Would make it easier to solder!

 

[daniboun]

Fin.

Nice, thanks for sharing.
I have always used the Walnut to make my snare drums,(I am a drummer and fond of woods) It is a wood that I like for its basic tonal properties) But the result is very nice here.

I imagine now that you will take the time to test and give us feedback on your impressions?

 

[daniboun]

Good to know! So is everyone connecting the ground from the 3e amp to pin 1 (jst connector) AND the xlr tab to the chasis? Would make it easier to solder!

Since the Pin 1 is grounded from the 3E Module, I would follow the old pratice. Just my opinion )

 

[restorer-john]

@daniboun Have you personally made any objective tests of this amplifier build and what data do you have to share?

 

[daniboun]

@daniboun Have you personally made any objective tests of this amplifier build and what data do you have to share?

Hi
I shared first impression here )) https://audiosciencereview.com/foru...-amplifier-micro-audio-psu.51454/post-1855547

 

[CamRector]

Nice, thanks for sharing.
I have always used the Walnut to make my snare drums,(I am a drummer and fond of woods) It is a wood that I like for its basic tonal properties) But the result is very nice here.

I imagine now that you will take the time to test and give us feedback on your impressions?

Yes for sure!
This amp sounds clean airy and crystal clear. Neutral city. Zero coloration. Completely nonexistent hiss.
Powerful.
This was my first amp build and will go to my friend who is biamping a 2way horn diy build.
This will power the 15in Faital pro 15pr400 drivers from 35hz-700hz. With 100db sensitivity speakers, this amp will be perfect for that load.
Big thanks you to @daniboun and many others who answered questions and gave advice to this newb.
Next on the plate is the 4channel version for my home system. Just waiting on Sami @MicroAudio to ship the SMPS1KS-PFCR2 and Mundorf caps!

 

[daniboun]

I wanted to share with you a little feedback that I got from a former director of the "la revue du son" specialized in the French Audiophile press. This guy was also one of the product managers from Siare and Audax and as sales director at Dynaudio and product manager at B&W and Focal.
He was super perplexed when I suggested he try the 3e Audio module....

I will let you translate so as not to distort his words) :

"En écoute à niveau raisonnable si je coupe le secteur du 3E Audio il fonctionne encore normalement durant env 25 secondes grâce aux 120.000uF de capas que j'ai rajouté.
Je peux te dire que secteur ou non le son reste le même, ce qui veut dire que la psu est quasi imperceptible, donc dejà assez silencieuse.
Avant les capas j'ai mis une une self de filtrage qui joue beaucoup car si je saute la self, le son est moins propre avec secteur, un peu plus "sale".
Donc l'alim de base à 45 € bien optimisée, ça marche déjà vraiment bien .
J'imagine donc avec la micro audio...
Je confirme que le remplacement des capas d'entrée par de très performantes transfigure littéralement l'ampli à l'écoute. Il est devenu pour moi hier l'un des 3 ou 4 meilleurs jamais entendus en 50 ans de Hi-fi ( et crois moi j'en ai entendu)."

 

[CamRector]

@daniboun
I tried a few translate programs and this message was still confusing.

“I confirm that replacing the input caps with high-performance ones literally transforms the amp when listening”

what caps?

 

[daniboun]

@daniboun
I tried a few translate programs and this message was still confusing.

“I confirm that replacing the input caps with high-performance ones literally transforms the amp when listening”

what caps?

He replaced the decoupling caps, here the picture he shared... (bipolar caps)
To be honest, I won't take any risk and not sure it is going to improve the measurements....

 

[lazerharp]

Also having trouble to understand when translating. Is it his modification that makes it as good as he says or what? What 45€ basic power supply? I´m confused

 

[daniboun]

Also having trouble to understand when translating. Is it his modification that makes it as good as he says or what? What 45€ basic power supply? I´m confused

This one for the PSU : https://www.audiophonics.fr/fr/alim...a-decoupage-smps-250w-48v-5a-pfc-p-18106.html
Personally I would not embark on such modifications. The module as it is sold is excellent even if we were to gain 2db or 3db in Sinad, I don't really see the use here.

 

[CamRector]

This one for the PSU : https://www.audiophonics.fr/fr/alim...a-decoupage-smps-250w-48v-5a-pfc-p-18106.html
Personally I would not embark on such modifications. The module as it is sold is excellent even if we were to gain 2db or 3db in Sinad, I don't really see the use here.

That psu is a little under powered no?

 

[Treborha]

If I understood correctly, he increased the capacity of these four capacitors to 120 000uF

 

[ModDIY]

If I understood correctly, he increased the capacity of these four capacitors to 120 000uF

I think this addition is more on the DC rail between the SMPS and the 3255 PCB

 

[daniboun]

That psu is a little under powered no?

Depends on speakers impedance and other factors. This has been discussed here

https://audiosciencereview.com/foru...-audio-480-1-29a-amplifier.50361/post-1812293

 

[brunes]

Here we go... the easy bit!
Going to try some speakOns