[ginetto61]

6v should be fine too. 12,6 is high, too high in my opinion,,,

 
Hi and thanks again.
No way to find a 7V or 8V EI transformer ... no way.  Values jump from 6 to 9.

It seems indeed that 6 and 9 are more standard values for secondaries voltage.

last thing that i would want is to fry the regulator ... that would be the end of all games for sure
i have to content myself with the stock design, to keep a much lower profile and ... to stop dreaming
hope the caps will do something anyway
if only this unit had the PS of the Tanly ... i would be very happy 
Regards, gino
 
P.S. in the end found one and bought it.
sadly not small enough to fit in the original case, but it looks ok
 
http://www.ebay.co.uk/itm/291216912314?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
 

 

[abartels]

Hi all,
 
First irreversible step in modding my MX-U8:
 
Removed the  IEC320 inlet which is VERY crappy quality btw and replaced it with a 100% red copper - rhodium plated one.
Because I needed some more room in enclosure for the 2x R-Core 28VA (with Copper shield) I had to mount the new IEC320
external, so I created a wooden block and mounted IEC320 in there.
 



 
 
Just waiting for the R-Cores to arrive so I can start the whole project.
 
So far done in advance:
 
-1 Building the 0.8uV noise PSU from DIYINHK with 4700uF-16V Nichicon FG's
-2 Replacing the 4x  2200uF-25V BC stock caps with 4x 2200uF-16V Nichicon FG's
-3 Fabricated NDK NZ2520SD TCXO's on adapterboards
-4 Replaced stock IEC320 with Red Copper - Rhodium plated one, mounted external
 
 
To do's:
 
-1 Mount R-Cores in enclosure
-2 Put some 3M AB5100S leftovers in enclosure under pcb-section
-3 Mount main pcb
-4 Mounting a full copper shield between psu-section and pcb-section (have to buy that one and make it fit in enclosure)
-5 Mount 0.8uV psu in enclosure
-6 Mount the NDK's on the main pcb
-7 Connecting all wires
-8 Put 3M AB5100S leftovers on caps and chips
 
-9 Closing enclosure 

 
-10 Light a candle and hoping MX-U8 will start-up correctly 

 
Pictures will follow asap
 
Cheers,
 
 
Alex

 

[ginetto61]

  Hi all,
 
First irreversible step in modding my MX-U8:
 
Removed the  IEC320 inlet which is VERY crappy quality btw and replaced it with a 100% red copper - rhodium plated one.
Because I needed some more room in enclosure for the 2x R-Core 28VA (with Copper shield) I had to mount the new IEC320
external, so I created a wooden block and mounted IEC320 in there.
 

..........
Pictures will follow asap
Cheers,
Alex

 
Hi Alex good morning and congratulations again for the very nice job.
I am waiting for the pics.
During the thread my interest for power supplies has grown exponentially.
In particular i am now obsessed with power supplies noise measurements.
I have a very cheap Hantek pc scope that i am trying to use  

... and i have come to the conclusion that is not enoug. 

Well ... maybe it could be if i can find a uV signals low noise amplifier ? 

I think its sensitivity is around 10mV ... but i am not sure about this.  Specifications are not clear.
I think that this kind of measurements are the acid test at least for power supplies modifications.
A stable clean supply i think is mandatory for any quality device.
 
Are you going to perform any noise measurement ? how ?
 
As i said my only chance is to find a suitable uV signal very low noise amplifier.

Thanks a lot again.
Kindest regards.  gino

 

[abartels]

   
Hi Alex good morning and congratulations again for the very nice job.
I am waiting for the pics.
During the thread my interest for power supplies has grown exponentially.
In particular i am now obsessed with power supplies noise measurements.
I have a very cheap Hantek pc scope that i am trying to use  

... and i have come to the conclusion that is not enoug. 

Well ... maybe it could be if i can find a uV signals low noise amplifier ? 

I think its sensitivity is around 10mV ... but i am not sure about this.  Specifications are not clear.
I think that this kind of measurements are the acid test at least for power supplies modifications.
A stable clean supply i think is mandatory for any quality device.
 
Are you going to perform any noise measurement ? how ?
 
As i said my only chance is to find a suitable uV signal very low noise amplifier.

Thanks a lot again.
Kindest regards.  gino

 
Hi Gino,
 
I'm not going to measure, don't have the equipment to do, can ask a friend of mine, but it's what I hear, not what I measure,,,,,
I follow design rules, selecting components, measurements would be ok too.
 
Today I made the copper shield for shielding / separating R-Core transformers from electronics enclosure, it looks quite nice,
it's 5mm thick copper 

 VERY heavy 

 

 

 

 
Cheers 

 
 
Alex

 

[ginetto61]

   
Hi Gino,
 
I'm not going to measure, don't have the equipment to do, can ask a friend of mine, but it's what I hear, not what I measure,,,,,
I follow design rules, selecting components, measurements would be ok too.
 
Today I made the copper shield for shielding / separating R-Core transformers from electronics enclosure, it looks quite nice,
it's 5mm thick copper 

 VERY heavy 

 

 

 

 
Cheers 

 
 
Alex

 
Hi Alex thanks a lot for the kind reply
Impressive slab of copper indeed !
I am very interested to see some pictures, even during the process ... i like pics a lot 

 
in the meantime i understand now that i have made an horrible mistake
i bought a LIPO battery that if pierced catches fire.

I understand also that putting it after complete discharge in a bucket of salt water makes it inert.
Is it true ? what a stupid mistake indeed.

Regards, gino

 

[abartels]

Hi Gino,
 
When I receive the R-Core transformers I will post all pics and describe what I did.
For now it looks it could take up to 2 weeks before receiving the R-Core transformers 

 
EDIT: They are on their way to my very helpfull middleman Riemann 

 , so, I expect them in a week or so 

 
When they arrive I will post a step by step "manual" including all pics.
 
 
 
What are you talking about your mistake? Are you planning to stick a pin or something in your LIPO?
Or, planning to throw your LIPO in a bucket of water???
 
Just use your LIPO for the purpouse you bought it for, don't see any problems at all.
 
 
I suppose it's a joke or??
 
 
Regards,
 
Alex

 

[ginetto61]

  Hi Gino,
 
When I receive the R-Core transformers I will post all pics and describe what I did.
For now it looks it could take up to 2 weeks before receiving the R-Core transformers 

 
When they arrive I will post a step by step "manual" including all pics.

Thanks a lot  Alex !
 

What are you talking about your mistake? Are you planning to stick a pin or something in your LIPO?
Or, planning to throw your LIPO in a bucket of water???
Just use your LIPO for the purpouse you bought it for, don't see any problems at all.
I suppose it's a joke or??
Regards,
Alex

 
given the Vsupply around 10VDC of the device i was thinking to try, as an experiment, batteries. Just for curiosity.
I looked in ebay and found these bloody LIPO batteries used for model elicopters and cars by hobbysts.
They are quite powerful and small size ... they even fit inside the Melodious box
So i bought one and now i am waiting to receive it.
Look here the risk (this could happen any time)
 
https://www.youtube.com/watch?v=-DcpANRFrI4
 
stupid me.  I do not want to run this risk for sure.
And i have decided to stop the idea of batteries.
The first thing i will do when i receive it is to dispose it in a possible safe way.
In a bucket of salt water and pierced to make it inert and then to the disposal center.

  bad thing ignorance ...
 
Bye, gino

 

[abartels]

  Thanks a lot  Alex !
 
 
given the Vsupply around 10VDC of the device i was thinking to try, as an experiment, batteries. Just for curiosity.
I looked in ebay and found these bloody LIPO batteries used for model elicopters and cars by hobbysts.
They are quite powerful and small size ... they even fit inside the Melodious box
So i bought one and now i am waiting to receive it.
Look here the risk (this could happen any time)
 
https://www.youtube.com/watch?v=-DcpANRFrI4
 
stupid me.  I do not want to run this risk for sure.
And i have decided to stop the idea of batteries.
The first thing i will do when i receive it is to dispose it in a possible safe way.
In a bucket of salt water and pierced to make it inert and then to the disposal center.

  bad thing ignorance ...
 
Bye, gino

 
Hello Gino,
 
I had several lipo's in several mobile phones, those batteries where NOT from original manufacturers, just very cheap replacements.
And, YES, I'm still alive 

 
 
If you use a good charger, there's no problem at all.
You don't have to throw them away!
 
LIPO, it's Lithium Polymer, it's used in more products than you can think of.
 
Cheers 

 
 
Alex

 

[ginetto61]

   
Hello Gino,
 
I had several lipo's in several mobile phones, those batteries where NOT from original manufacturers, just very cheap replacements.
And, YES, I'm still alive 

If you use a good charger, there's no problem at all.
You don't have to throw them away!
LIPO, it's Lithium Polymer, it's used in more products than you can think of.
 
Cheers 

Alex

 
Hi Alex and thank you very much for you kind support
but i am feeling that it would be better to wait a moment and try to learn before acting
I am waiting for an opinion about the Melodious used as stock with a Nad M51 that is indeed a very good piece of dac.
I have bought some Nichicon from Mouser and i think that in the end i will just use them
I have not enough skills and competence to do something more complex. I am a wannabe modder without any skill ...

However I will follow your project with the greatest interest hoping to learn
And the size of the box also does not help either. It is too small. Nothing fits in ...
By the way ... i have bough also some of these ...
 
http://i00.i.aliimg.com/wsphoto/v0/32302878570_1/1Pcs-font-b-DC-b-font-Power-Jack-Socket-Female-font-b-Panel-b-font-font.jpg
 

  Bye !  gino

 

[ginetto61]

Hi Alex !
 
Do you think the U8 could work with a 3.7x2 = 7.4 VDC  ? it is the series of two Li Ion batteries.
i have seen something interesting ... the Chord Hugo dac, quite a good one from what i read

it seems to work also with just two Li Ion 3.7V batteries 
So maybe also the Melodious ... 
They are really cheap on ebay and with many accessories like holders and chargers
 
http://www.ebay.com/sch/i.html?_odkw=li+ion+battery&_udlo=50&_sac=1&_sop=15&_mPrRngCbx=1&LH_BIN=1&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xli+ion+battery+6800.TRS0&_nkw=li+ion+battery+6800&_sacat=0
 

i do not know if 7.4 VDC would be enough to power the U8 circuits by the way.
and i wonder what is the current draw of the circuit as well ... maybe a charge would last only few hours
What you think ?
Regards,  gino  

 

[abartels]

  Hi Alex !
 
Do you think the U8 could work with a 3.7x2 = 7.4 VDC  ? it is the series of two Li Ion batteries.
i have seen something interesting ... the Chord Hugo dac, quite a good one from what i read

it seems to work also with just two Li Ion 3.7V batteries 
So maybe also the Melodious ... 
They are really cheap on ebay and with many accessories like holders and chargers
 
http://www.ebay.com/sch/i.html?_odkw=li+ion+battery&_udlo=50&_sac=1&_sop=15&_mPrRngCbx=1&LH_BIN=1&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xli+ion+battery+6800.TRS0&_nkw=li+ion+battery+6800&_sacat=0
 

i do not know if 7.4 VDC would be enough to power the U8 circuits by the way.
and i wonder what is the current draw of the circuit as well ... maybe a charge would last only few hours
What you think ?
Regards,  gino  

 
Hi Gino,
 
18650 cells are useable, you need 2 in series to get the desired voltage, and, dont forget, you need 2 sets to power the U8, at least, if you want to do it the right way,,,
 
Also, there are MANY chinese 18650 cells which are NOT capacity as described. Those UltraFires are most likely ripp-offs. There are UltraFire 18650 cells on the market
who have written 6000mAh on them,,,,,,,,,,,,,
 

 
I can tell you for sure that highest capacity is around 3300mAh. If you want to go this road, just buy the Panasonic 18650. They are of good quality and capacity is correct.
The 3000mAh versions from Panasonic are very good. They are in two versions available, with and without protection circuit. Buy the ones WITH protection circuit.
 
You can buy them here:
http://www.dx.com/p/3000mah-rechargeable-18650-battery-w-protection-ic-green-4-pcs-306878#.VX7A9M_tlBc
 
BUT
 
Often batteries from asia are marked as dangerous goods when shipping abroad, airfreight will probably decline package, so you end up with receiving your money back after
a few weeks,,,,
 
If you can buy them in your own country it is safest and fastest.
 
 
Cheers 

 
 
Alex
 
 
EDIT:
 
I just saw your UltraFire's are even marked 6800mAh hahahahaha, divide it by 2, they probably won't have that capacity either,,,,,
For what it's worth, I bought a flashlight a few months ago with one UltraFire 18650, marked 3000mAh.
The flashlight draw 1200mAh. After 20 minutes that 18650 cell was empty,,,,,,
 
That gives us: 1200mAh / 3 = 400mAh INSTEAD of 3000mAh
 
Cheers 

 

[ginetto61]

  Hi Gino,
18650 cells are useable, you need 2 in series to get the desired voltage, and, dont forget, you need 2 sets to power the U8, at least, if you want to do it the right way,,,
Also, there are MANY chinese 18650 cells which are NOT capacity as described. Those UltraFires are most likely ripp-offs. There are UltraFire 18650 cells on the market
who have written 6000mAh on them,,,,,,,,,,,,,
 

 
I can tell you for sure that highest capacity is around 3300mAh. If you want to go this road, just buy the Panasonic 18650. They are of good quality and capacity is correct.
The 3000mAh versions from Panasonic are very good. They are in two versions available, with and without protection circuit. Buy the ones WITH protection circuit.
You can buy them here:
Http://www.dx.com/p/3000mah-rechargeable-18650-battery-w-protection-ic-green-4-pcs-306878#.VX7A9M_tlBc
BUT
Often batteries from asia are marked as dangerous goods when shipping abroad, airfreight will probably decline package, so you end up with receiving your money back after
a few weeks,,,,
If you can buy them in your own country it is safest and fastest.
Cheers 

 
 
Alex
 
 
EDIT:
I just saw your UltraFire's are even marked 6800mAh hahahahaha, divide it by 2, they probably won't have that capacity either,,,,,
For what it's worth, I bought a flashlight a few months ago with one UltraFire 18650, marked 3000mAh.
The flashlight draw 1200mAh. After 20 minutes that 18650 cell was empty,,,,,,
That gives us: 1200mAh / 3 = 400mAh INSTEAD of 3000mAh
 
Cheers 

 
Hi Alex !
thanks a lot for the always very precious advice.
Do you have an idea of the current draw of the U8 circuit ?
However i see batteries not very handy to use and with many drawbacks.
Even before receiving them i am already abandoning the idea.
I am back to a more traditional power supply option.
I have been buying something on ebay ...
when i will receive them i will post some pictures
They are regulator kits ....
 
Lately i have been told that, on principle, it is possible to filter out a lot of the noise even with a SMPS.
Of course the filter must be very well designed and executed.
And that the noise spectrum (type of noise) it is also important, not only the level.
Of course if you have just 1uV from 0 to 1 MHz ... that is good

I have been thinking a lot to SMPS after seeing clock generators using them.
I do not have the least idea about what kind of filtering they are using.
They look like off-the-shelf units ... like those from TDK.
Mouser stocks many TDK models.
But then additional filtering is needed to get the noise really down.
This would be a much more convenient solution, of course.
So i am still wavering ...
Thanks again,  gino 

 

[Jerryfan]

Alex,

If you don't mind, how much do you have in parts in your u8 mods?

 

[abartels]

Alex,

If you don't mind, how much do you have in parts in your u8 mods?

 
Hi JerryFan,
 
The components in total exceeds MX-U8 itself,,,,,
 
1x 0.8 uV noise psu including shipment                   68,00
2x Nichicon FG 4700uF-16V                                     3,60
4x Nichicon FG 2200uF-16V                                     7,00
8x Schottky Cree diode                                           8,00
2x DIP14 socket                                                     2,30
2x NDK NZ2520SD including shipment                    20,00
2x R-Core 2x7V 28VA – Copper shield                     25,00
2x adapterboard for NDK                                         0,15
1x Tellurium RCA                                                   15,00
1x IEC320 Rhodium plated                                      15,00
1x Copper shield 5mm x 40mm x 150mm                 25,00
1x screws nuts & bolts                                             5,00
1x several materials (glue, wood, wire etc.)             10,00
1x Shipment costs several components                    40,00
 
And, i had to order some alternative for 3M AB5100S which I can't find nowhere anymore, those sheets were way too expensive,
don't have a model number or brandname, they look like 3M but are not the same. I won't add them to the list, otherwise the cost
would almost double,,,,,,,,,,,,,
 
 
Tomorrow I will start modding, sadly I have a customer after work this evening so can't start modding MX-U8 today 

 
 
Cheers 

 
 
Alex

 

[ginetto61]

Hi Alex !
this project looks extremely serious. I am sure the result will be fantastic.
 
I have only place the new Nichicon FG

 and i have already risked to ruing the pcb during the desoldering of the original caps

I am using exactly this desoldering pump here ...
 
http://image.dhgate.com/albu_280646795_00/1.0x0.jpg
 
it could be that i am using a too big nozzle

... because the small holes for caps on the pcb remained closed by the solder

I have to look for different nozzle sizes. 

I have to say instead that for bigger parts it works quite ok and it is very handy.
I will wait for your pictures before doing anything.
However the sound was good already in the stock version
and still good after the caps replacement.
... but better is always better.
Thanks a lot for disclosing your expertise and projects.
Kind regards,  gino