crackaly noises are cased by bad optical cable or improper sync settings. Its best to run these things as slave adat and your interface as internal sync.
I encounter it at times with the one connected to my m-audio FireWire 1814 system. I just turn off/on the ada8000 and its ok.
I have never had it mess up on my Event EZ8 ADAT card system.
once you bypass the mic pre's you have a very nice line level a/d converter.
the a/d converter is an Alesis/Wavefront Semiconductor chipset
they set up perfectly with my soundcraft studio board's direct outs.
this is how the mod goes - this is done on the skinny board in the front on all channels:
this is what you have to do for each channel:
1. remove both sets of 47uF capacitors
2. remove both 6.8k resistors (I just cut all of them out with some clippers)
3. remove both glass surface mount diodes
4. remove both 825 ohm resistors
5. remove both 2.49k resistors
6. remove both A1316 pin in hole transistors
7. remove both A06 surface mount transistors
8. install jumper wire across where the 47 uF caps were
9. install jumper wire across where the base to collector juntion of the A1316 pin in hole transistor was.
And there you go, if you feel that you cannot perform this mod yourself, consult your local TV/VCR repair shop. They would have the knowledge and equipment to do this task. and trust me, this mod is worth it.
attached is the schematics for it, GYRAF submitted it in the original thread. print it out and take it to the shop. Happy mods