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AK4490 USB Dac with dsd support.

Hi Guys, can anyone recommend a high quality volume control or potentiometer for a Valve DAC output signal. That way I can avoid to use a pre-amplifier and control the output right there in a DAC.

Is there anything better than ALPS 27 ?

Many Thanks
Mykhailo


Please find another place to ask like in the non commercial section. But i would suggest you DACT audio attenuators

BR

Sonny
 
Would someone mind posting the appropriate wire housing plus terminals for use with the 5-position output on the discrete board? Maybe even a Mouser p/n, perhaps? I'd really appreciate it.

Regards,
John

If you're referring to the audio line out, here it is. Those are Digikey parts but you can cross reference with vendor part #.

2 pin Molex KK .100 plug housing - Digikey : WM2000-ND
3 pin Molex KK .100 plug housing - Digikey : WM2001-ND

Molex KK .100 crimp terminal Tin - Digikey : WM1114-ND
Molex KK .100 crimp terminal Gold - Digikey : WM2312-ND

You cannot use a 5 pin Molex since they're two independent sockets.
 
If you're referring to the audio line out, here it is. Those are Digikey parts but you can cross reference with vendor part #.

2 pin Molex KK .100 plug housing - Digikey : WM2000-ND
3 pin Molex KK .100 plug housing - Digikey : WM2001-ND

Molex KK .100 crimp terminal Tin - Digikey : WM1114-ND
Molex KK .100 crimp terminal Gold - Digikey : WM2312-ND

You cannot use a 5 pin Molex since they're two independent sockets.

I will put the crimp housing and crimp terminals in the package.

BR

Sonny
 
All,
Thinking of getting this DAC but there is 2version of the PCM shield. Not sure which I should get.
What's the difference between the discrete DIFF/SE shield and SE shield? The difference is quite a bit @ 60+euros.

I will mostly use foobar outputting FLAC/APE to the DAC and I will also explore pi2/i2s volumio.
The output of the DAC will be connected to an integrated amp or a passive attenuator/tube amp.

Appreciate your help/advice to a noob.
 
All,
Thinking of getting this DAC but there is 2version of the PCM shield. Not sure which I should get.
What's the difference between the discrete DIFF/SE shield and SE shield? The difference is quite a bit @ 60+euros.

I will mostly use foobar outputting FLAC/APE to the DAC and I will also explore pi2/i2s volumio.
The output of the DAC will be connected to an integrated amp or a passive attenuator/tube amp.

Appreciate your help/advice to a noob.

Hi, The difference on the DIFF/SE Shield and SE shield, is due to the use of opamps on the SE shield where DIFF/SE is purely discrete. Relays is replaced by Discrete SSR which sound superior to the relays.

I will remove the option DSD filter from by product catalogue. The reason is that the 2. order PCM filter has less impact on the signal than the 3. order DSD filter

You can listen to DSD and PCM (WAV/FLAC/ALAC/AAC/MP3) files with the PCM filter and they will both sound great.


BR

Sonny
 
Discrete Preamp to be used with DAC and Frontpanel.

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
 

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Hi Sonny this is intrigying now looks like by the time I would be ready to start the assbly you would be offering the full set.

I have tow questions.

Would there be a separate volume control required for the pre amp to work ? If yes, what the impedance should be.

You are saying that pre amp would fit the DAC, meaning AK DAC right ?

On the other hand it has an r2r dac, would there bea n option to choose and external DAC or the internal r2r ?

What chipset would be used in the R2R DAC ?
 
Hi Sonny this is intrigying now looks like by the time I would be ready to start the assbly you would be offering the full set.

I have tow questions.

Would there be a separate volume control required for the pre amp to work ? If yes, what the impedance should be.

You are saying that pre amp would fit the DAC, meaning AK DAC right ?

On the other hand it has an r2r dac, would there bea n option to choose and external DAC or the internal r2r ?

What chipset would be used in the R2R DAC ?

I may have made some misleading here.

The Preamp has build in volume control. It is based on an R2R DAC. The R2R attenuator is based on the DAC8812 from TI using discrete opamps.

It is in the same manner as for example Mark Levison has done it.

The Preamp board can be used with the frontpanel only and with the AK4490 USB DAC where the frontpanel can select 1 of 4 different digital filters.

I hope it clarifies some points here.
 
Hi, The difference on the DIFF/SE Shield and SE shield, is due to the use of opamps on the SE shield where DIFF/SE is purely discrete. Relays is replaced by Discrete SSR which sound superior to the relays.

I will remove the option DSD filter from by product catalogue. The reason is that the 2. order PCM filter has less impact on the signal than the 3. order DSD filter

You can listen to DSD and PCM (WAV/FLAC/ALAC/AAC/MP3) files with the PCM filter and they will both sound great.


BR

Sonny

Thanks for the prompt response.

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.

How do I connect pi2 to this DAC?

Thanks again
 
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