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AK4490 USB Dac with dsd support.

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#1,643
To show How clean and simple it Can be when using out cap bank and soft start.

With this build up very few tools is needed in the assembly process.

Solder iron, fast on connector and a cheap crimptool.

I will offer a kit price without toroid.

img_2209.jpgimg_2208.jpg
 
#1,644
sonnya said:
To show How clean and simple it Can be when using out cap bank and soft start.

With this build up very few tools is needed in the assembly process.

Solder iron, fast on connector and a cheap crimptool.

I will offer a kit price without toroid.

View attachment 702037View attachment 702038
Click to expand...
Sonny, is your TPA3244 based 60W class d board / amp, a match for the Mirand A1 sq/price wise? As far as I remember, Grunnet liked it a lot. BR, Per
 
#1,646
You have to have good quality power supply parts.

I would suggest long life and low impedance capacitors

Low impedance usually have higher ripple current.

Lower impedance means less heat, longer lifecycle.

Absolute minimum 300VA toroid. 500VA.... But look at regulation on current load... It is given in %.... Lower is better meaning a more stiff supply.

Get a shielded transformer if possible.

I have not tested higher than +/-50VDC that is equivalent to 35VAC secondary.

Manual is in working.... I finishing it as fast as possible. But it is very simple to use.

BR

Sonny
 
#1,647
I am looking for the firmware according to the attached post (I own the AK4490 USB DAC V1). I checked on this thread but the latest firmware I was able to find is dated 27 dec2015 (post #705). No any help from Mirand website since, even if this dac is still available for purchase, there is no any sw which can be downloaded.
Is there someone who can help me?


sonnya said:
New firmware for the frontpanel when used with the DAC only.

Two weeks ago we have made a new firmware for the frontpanel used with the DAC only.

An externally hosted image should be here but it was not working when we last tested it.
Click to expand...
 
#1,648
sonnya said:
You have to have good quality power supply parts.

I would suggest long life and low impedance capacitors

Low impedance usually have higher ripple current.

Lower impedance means less heat, longer lifecycle.

Absolute minimum 300VA toroid. 500VA.... But look at regulation on current load... It is given in %.... Lower is better meaning a more stiff supply.

Get a shielded transformer if possible.

I have not tested higher than +/-50VDC that is equivalent to 35VAC secondary.

Manual is in working.... I finishing it as fast as possible. But it is very simple to use.

BR

Sonny
Click to expand...

Thoughts on this Avel Lindberg Y236803 500VA 35V+35V Toroidal Transformer
 
#1,649
michip said:
I am looking for the firmware according to the attached post (I own the AK4490 USB DAC V1). I checked on this thread but the latest firmware I was able to find is dated 27 dec2015 (post #705). No any help from Mirand website since, even if this dac is still available for purchase, there is no any sw which can be downloaded.
Is there someone who can help me?
Click to expand...

We have changed the website to the bad

I have a couple of people asking for the software and I am working on it
 
#1,658
I have some questions about A1 V1.2. Is the idle bias fixed, or can it be adjusted? Is it possible to run it with 50 VDC at low impedance LS? The adjustment for offset, will it remain stable after initial setup? Any measurements for noise available?

Is it possible to bridge 2 of those modules? If yes, is there a possibility to increase input impedance without sacrifying on performance?
 
#1,659
Joseph K said:
The sound: obviously, attention, subjective opinion coming! And first impression. Also the system is settling.

In the original version I have always very much appreciated a beautiful, refined, full, natural sound, with a hint of a romantic 'halo' around. A tube like sound. With a slight, beneficial veil, probably.. a slight middle-range emphasis.

Now it had changed. The new version opened up, bass is more impactful, contrast augmented, projects a bigger, wider and deeper soundstage, more precise sound but with a warm tone; gives the feeling of more dynamics..
Very entertaining; spectacular.
There is more agressivity in the highs - - now it still to be understood what part of it is still due to burn- in (not existent..) or more transparency revealing nasties hidden before (happens all time to me)...

Ciao, George
Click to expand...

I have done some listening on quite a few albums and I too found it is for the most part better than the original, except for one part which is the cello instrument. I find it less meaty and the tone is slightly different. This is my favorite music instrument and I think I will need to give the Op Amps some break in time and listen some more to confirm this sound signature change. I still have two original modules which I can use to compare.

I did have very similar findings like bigger, wider and deeper soundstage and a lifted veil as you mentioned but I don't have any of that aggressiveness on the highs for my part.

I still have to do lots of listening and especially some very complex music pieces to hear how the changes cope with this.

All in all, it is a very positive change

Do
 
#1,660
Positive

Yes, I do agree.
It is clearly just better, without drawbacks.
I was hinting at the possible problems, too early without break-in, and other problems from the system shown more clearly. This was holding back the first tests.

Since then we have done more controls, individually and in group.
Result is that I have more work...🙂 to modify the modules.

As mentioned already before, I'm listening to a heavily modified Mirand V. 1.0 dac, with NDK SDA clocks, new clock PS regulator, separate independent PS for each dac section, and a little Arduino board doing the re-configuration for DSD-direct mode.

Last change applied was to 'imitate' the new output schield, that I'm waiting for...
Being impatient, I have just removed the output mute structure from the present schield.

Taking up the risk for bump and noises.

Wov. Have been revarded with a strong change, not only another clean up in resolution, even more opening up of soundstage - - but even the tonality of the dac changed for more Italian sunshine..
Very nice.

I do think that at this stage this dac sounds at a real world-class level...
These two last mods from Sonny has it elevated further in a more than subtle way.

Ciao, George
 
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