AK4490 USB Dac with dsd support.

[sonnya]

Just to give you all an teaser. I will of course make an seperate thread for the Discrete preamp but here is an picture of the PCB.

The board has servo but also in this case we have decided to use an discrete approach. The servo can pull the output with +/-20mV. It is mainly the JFET vgs mismatch that sets the limit here.

• Discrete Servo
• JFET input discrete opamps
• R2R DAC 16 bit.
• +12dB Gain
• 5 channel DIFF/SE input
• Balanced output.
• No relays, only MOSFET switches.
• All stages runs in class A.
• Small size : 140x100mm

The price for this board is 389€. To get it functioning it needs the frontpanel and +5.5V,+15V and -15V supply

Ahemmm!!! 🙄 I have made an calculation error here. The price of 389€ is with frontpanel! 🙂 But you have to add 26€ to the encoder EM14A0D-C25-L032N.

But it is a better price for all.

 

[sebbyp]

Sonnya did you see my email about address?

 

[sonnya]

Sonnya did you see my email about address?

Yes i did. We will take care to use the right one.

 

[sonnya]

a little of topic here.

I have got some request if the output stage could be used for PCM1794A, ES9018.

It can be used for that, only the resistor configuration is a little off what is useful here.

So i am going to rearrange the resistor network to fit those two DAC's. It is the same board size only another resistor configuration.

For those who which to use an voltage output DAC like AKXXXX, AD1955, WM87XX, Soekris R2R DAC. They should still use the Discrete output stage i have made here.

BR

Sonny

 

[pinnocchio]

a little of topic here.

I have got some request if the output stage could be used for PCM1794A, ES9018.

It can be used for that, only the resistor configuration is a little off what is useful here.

So i am going to rearrange the resistor network to fit those two DAC's. It is the same board size only another resistor configuration.

For those who which to use an voltage output DAC like AKXXXX, AD1955, WM87XX, Soekris R2R DAC. They should still use the Discrete output stage i have made here.

BR

Sonny

Hmmmm... I would be very curious to try your output stage in I/V mode for my BII (TwistedPearAudio Buffalo II) DAC and compare it against OPC's NTD1 V2. This could be really interesting!

Do

 

[MisterRogers]

Yea, just sold my BIII NTD1 DAC, or I'd be lining up to compare too.

 

[sonnya]

Good Night [emoji41]


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[bavmike]

Good Night [emoji41]


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Nice work Sonny!!

 

[Myint67]

Hi sonny
I don't seem invoice yet
Speaker protection board and output shield.

 

[sonnya]

I will make it This evening


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[MisterRogers]

Anyone else get their discrete IV yet?

 

[sonnya]

They are assembled and testet. But i did have some difficulties getting the connectors and smps for those who have ordered smps. But we did receive them today, and we will ship them tomorrow . As promised the molex terminals are In the package as well.


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[sonnya]

https://vimeo.com/141726488

Firmware on front panel is running.

I will write about it in the preamp and frontpanel thread

But this part is ready, to ship with standalone or with Dac and/or preamp

BR

Sonny


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[pdb]

... I will write about it in the preamp and frontpanel thread ...

Sonny, I would consider keeping the preamp stuff (and frontpanel) stuff in this thread. They are kind of integrated with digital anyway and it is a lot easier to follow in just one thread instead of three. Plus the momentum this thread has gained. I personally don't mind reading reviews, comments and offerings on stuff that I (for now) has not delved into. Just my opinion. All the best, Per

 

[randytsuch]

So quick question.

If I order this DAC, with the discrete shield, and a front panel, I just need to add a +5.5 and +/- 15V power supply, and a chassis, right?

Is +/- 15 is unregulated, from 14.5 to 24? That what the DAC user's guide says, but I think the discrete shield gets power from the DAC, so I wanted to check if that was correct.

I'm looking for a USB dac with volume control. I think the front panel will give me volume control, and let me change the DAC filters.

Thanks
Randy

 

[sonnya]

So quick question.



If I order this DAC, with the discrete shield, and a front panel, I just need to add a +5.5 and +/- 15V power supply, and a chassis, right?



Is +/- 15 is unregulated, from 14.5 to 24? That what the DAC user's guide says, but I think the discrete shield gets power from the DAC, so I wanted to check if that was correct.



I'm looking for a USB dac with volume control. I think the front panel will give me volume control, and let me change the DAC filters.



Thanks

Randy

The +/-15 vdc should be regulated.

The preamp and discrete output stage does not allow more than +/-15vdc +/-1v




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[sonnya]

Some people have asked me how to connect it.

I have attached two pictures :

First one is dac and frontpanel only:

Second one is an complete setup.

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[Forane12]

Looks great!
What are the requirements for the preamp PSUs?

 

[sonnya]

The same as for the DAC.

It will need +5 - +5.5V<200mA, +15VDC, 300mA and -15VDC, 300mA.

The DAC uses +5 - +5.5V<100mA, +15VDC, 200mA and -15VDC, 200mA.

So they can both be powered by the SMPS ECL30UT03 without any problems.

BR

Sonny

 

[pdb]

..
I see many folks here use exotic Power supply for the DAC but you recommended XP ECL30UT03 Power supply. I read that there is a lot of regulation in the board design, and as a designer yourself, do you see the need for exotics or I should keep it simple for now using simple PSU such as ECL30TU03 ...

Good question.