Marantz av7005 vs av8801 vs Theta Casablanca

One other thing I would note is between the av7005 and av8801 streaming movies sound much less like an mp3. The av7005 would sound very digital at times. 

Sorry, that message posted before I was done.  I don’t know much about av8801 configuration quirks.  Probably best just to read the manual and try to work from there.  There are definitely some processors that will not do bass management (i.e. subwoofer output) for 2-channel music.  My old Krell HTS had that quirk.  However, the new Krell S1200 and Bryston processors will enable sub for 2 channel music.  If you are using an analog source (like turntable or external DAC), the Marantz could be acting as a pass through preamp, in which it does no conversion to digital for bass management.

Good choice working with an active crossover (like I mentioned before).  I have worked with Ashley pro equipment.  I’m assume you are looking at something like the XR-1001 crossover.  The Ashley stuff has a tube like bloom to the sound.  I believe part of the reason is that Ashley’s internal power supply runs at the bare edge limit of the op amps (+/-18V).   If you want something with a flatter more neutral response, look at a used Rane AC22 crossover.  Rane power supply runs at a more conservative +/-15V.

if you are willing to spend the money, the Bryston 10B is probably the best.  Fully discrete Class A analog circuits with big linear power supply.  Make sure you know which version.  Some versions have RCA, some XLR.  The Bryston will have the most resolution/transparency compared to Rane or Ashley.

if you can get the Emotiva and Marantz to sound good, you may not feel the need to bixamp.

There is nothing that you can do easily with the Emotiva other than a fuse upgrade.  I had XPA-1 Gen 1 in my system.  Currently, I am running with XPR-1 and XPA-1L amps.  Both of these amp versions use two fuses (such as 2 x 4A for the XPAx1L).   I found that my Emotiva amps sounded the best with one Isoclean fuse and one Furutech fuse.  It was an excellent balance of clarity and warmth.  I found that running two Isoclean was just too warm/slow.  Running with two Furutech was too thin/lean.  I am using a really fast high resolution Krell processor (not warm at all). In your situation, it might be that two Furutech would sound best because the Marantz is so warm/slow.  The type of interconnects and speaker cable and power cables could also affect the sound.

fuses are used to help “tune” your system to get further towards the type of sound you want.  I just gave you my two preferred fuses.  You can start however you like.  If you do get fuses, make sure to burn in before making any decisions.  100 hours for the Isoclean.  With Furutech, you need about 240 hours before it calms down (because of the rhodium).

Oh, you could do fuse upgrade in your Marantz AV8801 as well, if you wish. For this, I would recommend a 2A Furutech for the most speed and resolution. I don’t know the physical size, as I think the fuse is inside somewhere.

if you are cost conscious and don’t want to waste money experimenting with multiple Furutech/Isoclean fuse combinations, you could try the generic PADIS fuses for the Emotiva amps. The Isoclean are very warm, but very inviting in the sound.  There is definitely a magic with the Isoclean. The Furutech are extremely high resolution and transparent. The PADIS are somewhat in between.

as far as the Furman goes, I don’t know. Usually, people say to plug the larger amps directly into the wall, but others have had success with power conditioner. Best suggestion is to try it both ways and see if the Furman restricts the sound. Plugging into the wall could give more current which would be more muscle in the bass and the instruments would hit with more authority.

Thanks for all the input Aux. I'm going to get some fuses and give them a try after I A, B, C the preamps. 

Just a brief update on the av8801, I used the on screen Audyssey setup and was able to pinpoint the phase error that way. Looks like when I flipped the phase I might actually kept it the same on the rr surround. I was also able to run full range on the front 3 and after running Audyssey was able to add the subwoofer into the mix during 2 channel. I really like to feel the music. The room correction seems to sound much better than the av7005, after I tweaked some settings more to my taste. I will say overall the av8801 sounds great, I did notice a slightly digital / mp3 sound from the surround and rear channels on DTS matrix while streaming music. I'm going to try it tomorrow with vinyl. The av8801 seems to get pretty hot, doesn't seem to matter what you are doing with it. I think it may have cut off a few times, I thought it was the digital source the first few times but while I was listening to vinyl it cut off for a second but I was in the other room so didn't observe. I'm going to keep an eye on this, turned my rack fans on. I think I'm pretty happy with the current setting so I ordered a set of bookshelves to try out the height / width options. I'm going to continue with the av8801 until they get here before I hook up the Theta. 

Just another brief update, the av8801 is really growing on me now that I have the room correction figured out. I think the set of speakers I ordered to use as wides will be here today so I'm excited to see what 9.1 will sound like. I can say that the av7005 was great but I didn't like the room correction, this all changes with the av8801. I'm actually thinking about just selling the Theta because I really like all these channels, I'm not sure what it would cost to bring the theta to a 7.1 or a 9.1.