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

[daniboun]

I have just installed the Micro Audio PSU.
Even after 10 minutes after turning on the upgraded Amp the differences between MP-H250S48 Power Supply and Micro Audio SMPS630-SO are obvious and clear.
Micro Audio PSU is just a masterpiece with increadible impact on sound quality. I have got an impression as if I powered on a different, much better amplifier.

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I see you have probably a different version. Can you tell us the value of the output caps next to the DC plugs. ?

My version comes with some Elna 63v 4700uf.

 

[bugal]

I see you have probably a different version. Can you tell us the value of the output caps next to the DC plugs. ?

My version comes with some Elna 63v 4700uf.

2x Nichicon 3900 uf 63 V

 

[daniboun]

[

2x Nichicon 3900 uf 63 V

Will try next month to add an extra Capacitors board with no rectifier bridge and two high-frequency snubbers to filter the high-frequency noise to see if it makes an audible difference. I ordered an audio grade one from Connex. Wait and see -))

 

[brunes]

Are you thinking to add capacitors after the SMPS i.e this..
I only ask as I have the boards but didn't fit them

 

[daniboun]

Are you thinking to add capacitors after the SMPS i.e this..
I only ask as I have the boards but didn't fit them

I already have this one but not populated yet... --))
and YES I know about bus pumping etc (as already discussed here)

I am talking about the Connex with high-frequency snubbers and some extra caps.
This is a test just out of curiousity )

 

[312elements]

@daniboun are there any other power supplies on your radar that you’re interested in experimenting with? The MicroAudio is discontinued and they’re designing what V2 will be now. It would be cool if there were another unregulated SMPS to test to verify if it’s the unregulated supply or perhaps something else that is responsible for the changes in the sound presentation.

 

[MicroAudio]

@daniboun are there any other power supplies on your radar that you’re interested in experimenting with? The MicroAudio is discontinued and they’re designing what V2 will be now. It would be cool if there were another unregulated SMPS to test to verify if it’s the unregulated supply or perhaps something else that is responsible for the changes in the sound presentation.

SMPS630 REV-2 is identical to the current model but with some changes/updates.

Thanks

 

[daniboun]

@daniboun are there any other power supplies on your radar that you’re interested in experimenting with? The MicroAudio is discontinued and they’re designing what V2 will be now. It would be cool if there were another unregulated SMPS to test to verify if it’s the unregulated supply or perhaps something else that is responsible for the changes in the sound presentation.

Hi
Arfff the only one now that is unregulated with a single rail = Micro Audio SMPS630-SO. I wonder what V2 will bring )
At the time there was Audio Power from Italy which manufactured unregulated Audio grade single rail PSUs

PS : I noticed that my Micro Audio PSU is different from all the versions that I have seen in pictures on this forum... I have a different mini transformer for aux. and higher value output caps for DC

 

[daniboun]

SMPS630 REV-2 is identical to the current model but with some changes/updates.

Thanks

Could you please expand on this point and say more?

 

[MicroAudio]

Could you please expand on this point and say more?

The plan is to remove some unnecessary output connectors, eliminate the REG/UNREG voltage selection, and add more output capacitance.

Also, the SMPS gate drive system will be replaced with a better one.

If you let me know what you would like to see in REV-2 that would be great.

REV-2 will have the option to eat 100.000uF ~ 160.000 of output capacitance as an option.

Thanks

 

[daniboun]

The plan is to remove some unnecessary output connectors, eliminate the REG/UNREG voltage selection, and add more output capacitance.

Also, the SMPS gate drive system will be replaced with a better one.

If you let me know what you would like to see in REV-2 that would be great.

REV-2 will have the option to eat 100.000uF ~ 160.000 of output capacitance as an option.

Thanks

1)Should be nice to see an active PFC function )
2) Should be great to get real measurements on your site )

Question : what do you mean by REG/UNREG selection ? Should we understand that V2 will therefore be regulated?

 

[MicroAudio]

1)Should be nice to see an active PFC function )
2) Should be great to get real measurements on your site )

Question : what do you mean by REG/UNREG selection ? Should we understand that V2 will therefore be regulated?

Yes, there will be major updates on all product manuals, etc, but that will take some time.

Adding active PFC will increase the cost of the product.

However, the SMPS630 was made as a low-cost product without active PFC.

If you are looking for an active PFC version you can look at SMPS1KS-PFCR2 for example.

The REG/UNREG was for the AUX.

Thanks

 

[daniboun]

Yes, there will be major updates on all product manuals, etc, but that will take some time.

Adding active PFC will increase the cost of the product.

However, the SMPS630 was made as a low-cost product without active PFC.

If you are looking for an active PFC version you can look at SMPS1KS-PFCR2 for example.

The REG/UNREG was for the AUX.

Thanks

OK makes sense.
Looking forward to see the new version.

low cost but well made anyway

 

[daniboun]

Would there be a penalty in using the Micro Audio PSU with an umbilical cord (less than a foot). What I’m envisioning is the power supply in a matching case in the same stack. I ask because it seems like that could scale a little bit better as these boards keep getting better. If no penalty, any suggestions on what to use as the connector? Could I just run XLR between the units?

In my humble opinion: the most important thing is to keep cables as short as possible. Prefer sections of 1.5 to 2mm2 and don't neglect the welds if you do it yourself and twist it ! If possible, use shielded cables. If you carefully read the second AHB2 Benchmark ASR test you will understand that distance between connectors and module cares.

 

[bugal]

Twisting pair of cables is not necessary if you put/run them close together lengthwise - that's what I acctualy read in some DIY guidelines. The point is to avoid loops of wires and spreading them apart. Is there any real sonic value (interferences) of twisitng the cables on a distance of 10-30 cm?

 

[daniboun]

Twisting pair of cables is not necessary if you put/run them close together lengthwise - that's what I acctualy read in some DIY guidelines. The point is to avoid loops of wires and spreading them apart. Is there any real sonic value (interferences) of twisitng the cables on a distance of 10-30 cm?

A twisted pair used as a balanced line can significantly reduce the effect of noise currents induced on the line by connecting electric or magnetic fields. The induced currents in each of the two conductors are very almost equal. Twisting ensures that both wires are on average at the same distance from the interfering source and are equally affected. In this way, the noise creates a common mode that can be canceled in the receiver by detecting only the difference signal, the latter being the desired signal.

It costs nothing to twist your cables, the more can the less ) just my opinion

 

[bugal]

I think it would be great to prove it in practise by figures.

Kind of test, as completed by Amir - the same amp tested with twisted and then not twisted pair of wires (eg. between the PSU and amp module).
Then comparison of SINADs.

 

[somebodyelse]

Hypex talk about twisting as important for avoiding crosstalk between input, output and PSU in the nc400 datasheet. I don't remember seeing measurements comparing with and without twist for the same cable routing though.

 

[daniboun]

Hypex talk about twisting as important for avoiding crosstalk between input, output and PSU in the nc400 datasheet. I don't remember seeing measurements comparing with and without twist for the same cable routing though.

I don't think anyone is going to upset Bruno Putzeys, right)
@bugal > so I see no reason not to Twist your cables)

 

[bugal]

I don't think anyone is going to upset Bruno Putzeys, right)
@bugal > so I see no reason not to Twist your cables)

@daniboun > the question is how can you accept the twisted wires theory without the SINAD proof?

@amirm > what do you think about such testing project? the same amplifier tested a) with hook-up wires twisted and b) not twisted (running tight together in pairs)?
This way we can find out if twisting the wires has got any effect on the SINAD score (which is one of the most important equipement quality factor here). I am really curious about the outcome.