I set up my HDS-42AVR 4K switch designed to pair with the Outlaw 975 Pre-Pro several days ago, and just yesterday I went over to Pat Sklenar's (psklenar) house to help him put up his new Sony 4K UHD HDR set onto the wall mounts. Pat got me interested in Outlaw products back in the Outlaw 1050 days.
We also got the 4K switch set up with his system. When I left his house all that was left for him to do was reprogram his Harmony remote to replace his old TV for the new one in the remote and a couple other items related to installing the switch and using multiple HDMI ports on the TV. (HDMI/ARC from the 975 and his other high speed HDMI port for video from the 4k switch)
First impressions from both of us is the switch is great. Once hooked up and configured (only real configuration is on the 975 side) it works seamlessly to get your 4K devices video onto your 4K set and the audio pumping through the 975.
When it switches devices The 975 picks up the audio format being put out by the device and displays it on the 975's display for a couple seconds and shows which speakers are being used etc.
My first note to anyone setting up the switch is to RTFM!! Read the documentation that comes with the switch and follow the directions. Most importantly is page 4 where it explains how to hook the switch to the 975. I had some initial issues getting it all to work and it was 100% my fault for not RTFM'ing and following the instructions in the documentation that came with the HDS-42AVR. A call to Outlaw tech support and they got my brain "right" (shut up Pat! <g>) and once I had followed the directions from the documentation that came with the 4k switch everything worked.
Connect the Audio Only port on the switch to HDMI1 on the 975. It also explains that all the ports you are using on the switch have to have their corresponding HDMI Input settings on the 975 set to HDMI1 for both video and audio input.
The "video" setting isn't all that important since no video will be going through the 975, but you have to set the video to that HDMI1 in order for the audio input to be set to HDMI1 for all those ports.
Put the HDMI Out on the 975 into your HDMI/ARC port on the TV. This will allow you to get audio back out of the TV for any "TV" features like built in tuner, Smart TV apps, etc and getting the audio through your 975.
Put the Pass Through out of the switch into another HDMI port on your TV. I would suggest checking your owners manual for the TV to pick the next best HDMI port. As an example my set (Vizio M60-C3) has one other HDMI port that has a higher speed capability than the other ports and that is where I connected the pass through from the switch to the TVs HDMI input.
My suggestion is to plug your 4K devices into the same port # on the switch that you had them plugged into on the 975. A) This makes it easier to remember what to set where when you're using your remote to switch devices since it is the same that you were using before.
B) if you are like myself and Pat and are using a unified remote (Harmony in our case) to do all your switching it will cut down on reconfiguring the unified remote to work with the new switch in the system and using multiple inputs on the TV.
On the subject of Non-4K devices you may have hooked to your 975 now you can put them on the switch as well. However I had an issue with my cable set top box in that the Vizio wouldn't sync the video when going through the 4k switch so I had to move that back to the 975 (where I had to set that port to autoscale from the default of native resolution).
I don't fault Outlaw for this, neither the 975 nor the switch. My cable box is an older model. I have Comcast/Xfinity and they want me to upgrade to the X1 system, but I was told if you do that all your boxes have to be X1 boxes and the X1 box doesn't work with my SageTV PC based DVR (NOT giving that up until someone pries it from my cold dead hands!!).
Pat's cable STB (Cox Cable) which is a more current model STB worked fine going through the 4K switch, so most likely yours will too but if not you can still use ports on the 975 that aren't being used on the 4K switch.
I had to fiddle with the placement of the remote IR receiver for the 4K switch (there is no built in IR receiver) to get better reception from my remote controls (both 975 remote and the Harmony). Like a lot of remote IR receivers placement may have to be experimented with for the best reception.
Initially I would suggest (per Outlaw tech support) placing the remote IR receiver right near the left hand side of the 975's display window where the 975's IR receiver is located.
Anyway. My impression of the HDS-42AVR is that it is a great addition to the 975 to get your 4K video and audio working seamlessly. And now I get to see the gorgeous 4K content on my 4K TV and all the great audio through my 975! Well worth the price of the 42AVR IMHO.
I hope this helps people decide whether to get it (If you have a 4K TV then I'd say it is a YES!), and also hopefully some of the tips I mentioned will help others in configuring it with their 975 and TV. If I have anything wrong, or left something out I'm sure someone will reply to add something I missed or correct something I may have misstated.