AMR DP-777, what am I missing ?

I have no directly relevant experience, but it seems to me that you may gain some insight that would be helpful in formulating a course of action if you were to experimentally try a different computer; a USB 3.0 port if you are presently using a USB 2.0 port (on the different computer if necessary); a USB 2.0 port if you are presently using a USB 3.0 port (on the different computer if necessary); and different USB ports on each of the computers. And definitely also try a better USB cable.

Also, as an experimental measure, it may be worth TEMPORARILY trying a cheater plug to isolate the AC safety ground connection of either the computer or the DAC. Or both, for that matter. I'm envisioning the possibility that ground loops may be causing jitter or other issues in the DAC.

Very nice system you've got there, btw. Good luck. Regards,
-- Al

01-31-15: Douglas_schroeder
I wouldn't dream of running any file-based playback with a trash USB. It would eviscerate the sound quality...I only takes one garbage connection to take down a system. One.

+ 1. Single or preferably double-xlr connections from server transport to dac for me thanks.

Other dacs I have tried are: triode labs dac, nad m51, benchmark hgc, wavelength cosecant. Amr in my memory seems the beat of the lot.

The usb input is async for sure. Yes I use usb

Douglas, can you recommend some usb systems, I am assuming you mean a usb to spdif converter.

I believe that a better usb cable might help but don't think it will gve me the order of magnitude performance jump I am looking for.

Thanks for ic recos willie , will check them out.

Al, my current plan as you suggest, is to switch my iMac to a Mac mini, since my iMac seems to be really slow and unresponsive these days. Then next maybe try a USB filter system.

Am planning to start with the ifi USB filers and cables system by Amr , unless you guys think there is something better I should try first

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.