ackoDAC based on ES9018

[acko]

Hi Everyone,

I have started a DAC design based on the Sabre32 ES9018 for DIYers. I am finalising the design at this stage and waiting for parts to test this. Briefly the specs are as follows:

1. ES9018 in 2 or 8-Channel mode.
2. On-board high speed comparator for SPDIF.
3. I2S, DSD, PCM Inputs
4. Precision low jitter clock based on Crystek CCHD-950 8MHz
5. 7 Independent power supplies for the DAC and output stage
6. Low noise internal power based on LM4562 and LT1763
7. Separate ground planes for digital and analog paths
8. Polymer electrolytics caps, COG creamics and low noise thin film resistors
9. 70u thickness copper with Gold flashed pads and anodized tracks.
10. Machine soldered in an ISO9000 facility.

Note: External Micro needed for control.
External IV stage required


Also planned Bare or partially loaded boards for those who wish to tweak or source their own parts. See attached prototype pics. Any feedback appreciated.

[chungtat]

May be digital POT for volume control?

[analog_sa]

Regulators are remote?

[acko]

External Micro can implement digital volume control with a switch select if this option or external volume control. This will connect to the header marked "Control". I will get this done before releasing the DAC kit. I am also thinking of putting the Micro on-board for convenience but not sure if this will upset the low noise circuitry.

Thanks, acko

[acko]

There are low noise on-board regulator placed very close to the DAC chip but yes pre-regulators and other power feed components are extrenal. The supply can be sourced from single feed for convenience or go for fully separate ones for best performance. I will also do matching psu boards to make things easier to setup.

Thanks, acko

[agent.5]

Any chance that your board will allow easy switching of input modes? I am looking for a DAC allowing more than one SPDIF inputs and I can select which input for conversion on the front panel.

[acko]

Yes, this can be done on board with the Micro doing the switching/selecting in response to say a push button. Will try to add this feature

[acko]

All Parts have arrived and NDA with ESSTECH signed for full access to design information. Board design being finalised and should go for fabrication in 2 wks. Micro design and programming in progress. Plan to incorporate Vol control, switch selects and possible PC interface for user to set relevant ES9018 registers

[acko]

Originally posted by agent.5
Any chance that your board will allow easy switching of input modes? I am looking for a DAC allowing more than one SPDIF inputs and I can select which input for conversion on the front panel.

8 Channels of SPDIF now on-board. Will see if I can squeeze in the isolation transformers as well.

[agent.5]

Originally posted by acko


8 Channels of SPDIF now on-board. Will see if I can squeeze in the isolation transformers as well.

WOW.

If you have not finalized the DAC layout yet, I am just thinking that it may be nice to add one extra tiny hole connected to the clock output. This way, people will be able to easily use the clock output as a world clock to sync something else, say a CD player or Squeezebox or whatever.