@rrboogie
Not a good idea to use one set of interconnects from DAC to sub-woofer and another to preamp. One set to preamp and two sets out from preamp to amp and sub-woofer, even if you have to use Y-splitters. That way your preamp volume control will control all. Otherwise a mess with control of volume.
I have used three different preamps with my 004 and 005. The Freya+ was my middle pre and is very good for the price. The emphasis is on: for the price. I used it with NOS Chrome Domes. Having tubes somewhere in the system when you are running a solid stage DAC (which is to say, most of them) is great. The Freya+ easily beat out a very good SS preamp. I found, though, that I couldn’t live without a balance control and for this and other reasons went to a much more expensive tubed preamp. It’s all much, much better. The moral of this story is that to hear it at its best you cannot match the Musetec with components appropriate to only a $3000 DAC. In this I agree with @sns . In your place I might consider selling all your pre- stuff and getting something better. But I’m not there and have not heard it all as you have.
As for USB cables. They really do matter and IMO are very system specific. I say first settle on your preamp. AQ Diamond works for a lot of people including @sns. It did not work for me as I wrote earlier. Nor did a custom silver core cable that did fine with the 004. AQ Pearl at 5% of the Diamond price works better here. But it did lose a bit of sparkle/openness that should be there. A change in the interconnect between DAC and preamp is proving just right along with the Pearl. I’ll write about that cable in a bit. So my advice: try interconnect and USB cable. Buy cheap or buy where you can return.