AMR DP-777, what am I missing ?

Essrand, no, I do not mean USB to S/DIF converter; yikes, that would be horrid! Converters have a great capacity to suck life out of performance, and I try to avoid them whenever possible.

I did mean a quality USB cable to go from your Mac to the DAC. If you have no experience with aftermarket USB cables, you will be surprised at the difference they make. Simply because you don't think it will make that much difference is a poor reason not to pursue it. When I entered this hobby about30+ years ago I didn't think cables at all made that much difference, and I was way wrong about that! ALL wires, ALL connections are critical if one wants to pursue the best sound possible.

If you mean in your above post USB "filter", my opinion is to avoid filters like ferrite rings around cables, etc. My conclusion is that they do filter out noise, but also harm the micro dynamics. Opinions differ on this, as you can imagine. :)

I am currently running a $1K USB cable, the Clarity Audio Organic USB. Pricey, yup, but it bested about ten others including at least one more expensive. I wouldn't be without a premium USB cable, as it is the lifeline for the files to reach the DAC. Screw up that connection and you have fairly killed your chance at premium sound. :)

There are some obvious basics required. Quality isolation and power conditioning for your digital. (And I do the same for analog.) Heed the efforts of Wadia and Esoteric with respect to power supplies and assume similar effectiveness for Spectral digital and Alpha.Different digital components, and power supplies, discharge and/or have varying degrees of sensitivity to line noise. Briefly, if you don't address these items you will never know what any particular component or your system is capable of. "Sound Application" is an outright steal used and supremely effective. "Equitech" provides exc isolation via their patented process of achieving finely balanced (noise killing) transformers. Be prepared to enter a different realm of musical enjoyment :-) . Have fun.

The usb cable is extremely important. Try a Wireworld Platinum usb cable. I was surprised at the difference. My 2 cents.

Douglas, Elsneb

It would certainly make me a very happy camper if a simple USB cable solved my problems.
I am surprised with all the talk about USB Power supplies, SPDIF converters with clocks in them in the other threads that you think they harm the sound.

I will be posting my experiments as I perform them in this thread so maybe it will useful for someone else in the future.

step 1: replace imac with a mac mini that has a SSD and more RAM.
step 2: try a good USB cable, maybe wireworld platinum.
.....
Lets see if that works, before I try out specialized music servers or usb converters.

Williewonka,

Looks like the USB cable you mentioned is sold out.
Any ideas on how to get a cable like this elsewhere.

Thanks