Extigy hacking info

[tiroth]

Thought this might be of value to some folks.

Unresampled signals:
===============

If you want signals before they are munged by the Creative ICs, take them from the Zoran IC (ZR38601) outputs. They output 44.1kHz for CD and 48kHz for Dolby Digital.

C91* MCK
R85 BCK
R68/R69 Front speakers (same signal both resistors)
R70 Rear speakers
R72 Center/Sub

There is no easy takeoff for LRCK, but this signal goes through a via near R85, on the Zoran side. Check this carefully, then flip the board and notice the three traces running side-by-side across the board. The one closest to the rear (output side) of the PCB is the LRCK. Solder an 0805 resistor to this via (30-40 ohm) and then take the signal from the resistor.

*You must remove C91 as it is connected to ground and loads the output too much. I soldered a high-value 0805 resistor here as that makes for a more reliable take-off point.

You should turn the CMSS feature "on" if you want to use these outputs. The CMSS does not appear to affect CD-audio at all (no signal on Rear, Center), but the multichannel outputs won't work for Dolby Digital if CMSS is off. (Note: I verified that the outputs are discrete, not matrix-decoded. Go figure. For CD-audio, the CMSS decoding is done by the Creative IC.)

There is no processing done on these outputs; you will not be able to use the Extigy digital volume control.

Resampled signals
=============
If you need the volume control and/or want the CMSS function for stereo inputs, you must take the outputs near the UDA1328 DAC IC. Here are some easy take-off points:

MCK R106
BCK R101
LRCK Pin 11 of DAC or Pin 1 of U4 (near headphones)
D0/D1 Pin 12 of DAC
D2/D3 Pin 13 of DAC
D4/D5 RP13 bottom-most pad (i.e. towards output side of PCB)

You could of course take all outputs from the UDA1328 but that was a little crowded for my taste. Sorry I didn't list the speakers that correspond but I am not using these outputs so I didn't test.


Wrap up
========

You can also use the 6-channel S/PDIF outputs if you get the special cable or remove the jack. The board draws only about 300mA in my application, in case you feel like ditching the switching supply. You also don't need to worry about the voltage that much; it isn't really important for the digital section. I run at about 9V preregulated.

Also, the power switch does nothing but turn some of the outputs off. Still sucks power and runs the clocks.

I see refurb Extigies on eBay now for $70. This makes a nice core for DIY DD project. No bass redirection or delay controls are available though.

[tiroth]

Oh, I forgot to say that the Extigy uses a RS-422 transceiver for the S/PDIF input. This is schmitt-trigger input. Don't tell Jocko.

[Tieftoener]

AWESOME work and effort...!!

Thanks Tiroth! Now I have to get one... This will be a great solution to my work PC audio system.

[dunderchief]

Extigy doesn't work with KX project drivers does it?

[tiroth]

Nope.