I got it working! 2 cables for my entire setup. The USB from the amp to the computer, and the guitar cord from the guitar to the amp. That's it.
I can now use all the features within Rocksmith with a clean signal going into the game no matter what settings I want coming out of the amplifiers speaker. So you can use just the computer, just the amp, or the computer and the amp.
Okay. Lets see if I can explain this. It took me all night to figure out.
First of all you have to use the "No cable" patch. This is simplest method I found for that:
That is it as far as software goes. Very simple.
Download this from that page and you will unzip two files.
NoCableLauncher-m-binary.rar (Lastest version with multiplayer support)
NoCableLauncher.exe & EditSettings.bat
Doesn't matter where you put them, just keep then in the same folder. No editing of any the installed files is needed.
Before you do anything with those files some things have to be setup first.
Of course you have to have your Katana Boss Tone Studio Software installed and all the drivers working etc. This all worked the first install when I got my amp no problem and as expected.
You also have to have your Rocksmith installed and working of course.
Without anything open (nothing accessing the Katana amp or it won't let you change this setting), go to the start menu apps and open Boss>Katana
This opens the Katana Drivers Settings.
You must change the sample rate to 48000 Hz. The default was 44000 Hz and you simply will not get any audio in Rocksmith with this value. Apply that change and close out the driver settings. If you cannot change this setting, then that means you have something open accessing the amp via USB or something locking it up from editing. I ran into this the first time because I had Boss Tone Studio open.
The next thing you have to do is go into your computers "Manage Audio Settings". Select the Recording tab. Set SECONDARY KATANA to the default device. You should have a green check mark on it once this is correct.
Disable PRIMARY KATANA. If you have anything else active in the recording tab you may have to disable it. Before I disabled this, Rocksmith kept thinking I had "More than one Real Tone Cable Connected".
Once you have done this, you should be able to run the EditSettings.bat file. This will pop up a window that lets you select the input device. You should not have to change anything here though if you followed my above advice. It should already show Player 1 Audio Device as Secondary Katana with the VID and PID it pulled in on it's own.
Hit the Save button. This will create a Settings.xml file in the folder that will be used by the NoCableLauncher.exe.
Once you have done this, just run NoCableLauncher.exe
It should launch into Rocksmith as normal. For whatever reason, I seem to always have a distortion tone set in Rocksmith when I load. Change that to something clean just so you can hear something closer to your real guitar sound.
On my setup for whatever reason I could not get quite enough volume for auto calibration to go high enough (yes, the guitar was turned up all the way). I ended up going into the Manual Gain Override in Rocksmith, turned it on and set it to 10dB. I could probably go a tad lower, but this is pretty good as is. I then went back to the tuner and opened the calibrator. The first part gives you a message that you have manual override set and that it is skipping that first part. However, it then goes into letting you check the setting. You can play hard and make sure it does not clip out at the top and make sure it mutes flat line. Mine was very good and finished the calibration. After that you go back to the tuner and you should be able to tune up.
I played a couple tries of a song and it detected fine. Now you can either mute your guitar in the game and just use the amp, or you can use just the computer (amp has to be on). You can also just use the game as is on the computer and mix in your amp in the background. Whatever you want!
There is one downside I found. You must re-enable the PRIMARY KATANA in the recordings tab of the sound settings, or you will not be able to communicate back to the amp using the Boss Tone Studio software. It needs access to that to communicate. That is the only annoyance I see so far. I am not sure if there is a workaround to make Rocksmith let you leave it active without seeing it as another faux Real Tone cable.
There may be a way to feed the games sounds over to the amp also via USB and for sure using the AUX IN via an audio cable, but I am not getting into that tonight.
If you want to use the computer sound and the games tones, you can also just add a little hair of ambient from the amp on the .5 Watt setting and it can help hide a little of the latency in the computers audio (if you have any).
I have to add that the Katana 100 amp is awesome so far. Very glad I sold my Marshal Valvestate and got this thing! I don't think you can touch anything like it for the bargain $350 price tag! (got mine a little cheaper)
I still may consider a Splitter before the amp. It just depends if the disabling of the other items in the Recording tab gets annoying or of I find a work around. Not having the extra Real tone cable routing around and a splitter is nice. This is a very clean/simple hardware setup without them. It also frees up a USB port on my computer.