Schmalle

Short to sleeve means that stuff is switched when there is a short (resistance close to zero Ohms) between tip and sleeve (and ring to sleeve if two functions can be switched) on the footswitch jack. [Tip, ring and sleeve are the contacts on the 1/4" jack - you probably know about mono TS (tip-sleeve) and stereo TRS (tip-ring-sleeve) cables] The Marshall does that. This does however just mean that nothing will be damaged. It does not mean that it works properly - it might introduce hum (a ground loop) or not switch correctly.

The second question can be answered with no - it is absolutely not mandatory to use a cab / IR. It just adds color: a realistic representation (or high resolution eq curve) of real world cab+mic combination. The first question opens up a DEEP rabbit hole - if you craw through you come out as an audio engineer. It's like a chef needing to learn ingredients, seasoning, cocking recipes for different meals. Ingredients: Characteristic sound of of different speakers and mics, sound of different cab constructions, mic positioning, combinations of multiple speakers and mics among other stuff. Seasoning: Eq-ing, low and high cuts, ambience and so on. Recipes: What combination works for what sound? Learning by doing and stealing recipes from wherever you can find them including existing presets. Here are a few reads for a start: https://blog.line6.com/2020/06/30/youve-never-actually-heard-that-amp/ https://blog.line6.com/2022/12/21/dave-hunter-tone-in-a-box-part-1-tone-tweaking-via-cab-swapping/ https://blog.line6.com/2023/02/04/dave-hunter-tone-in-a-box-part-2-tone-tweaking-via-speaker-swapping/ https://mastering.com/approach-equalization-two-types-eq Finally: If it sounds good it is good. Trust your ears, but not too much!

You might want to set the Global Settings -> Ins/Outs -> Output Level to Line to get a signal that is about twice the level of Inst.

Do you run the latest HX Edit? Which OS?

The greyed out "customize" is normal for snapshot use. I can't see why this doesn't work for you - the toggle programming should be as easy as this: Switch to Snapshot Mode and make sure you're on Snapshot 1. Switch to Footswitch Mode. Go to Command Center. Set FS1 to Snpsht, Pres/Release, SNAP2, None. Press FS1. Change "Press" to SNAP 1. Press FS1 - it should toggle "Press" between SNAP1 and SNAP2 now. When you leave Command Center and are back it Footswitch Mode it should now display the Snapshot symbol for FS1.

That seems to be legit power supply, but one never knows how much manufacturers cheap out on parts. I've repaired several LCD screens with a similar issue then your HX. Not powering on - only if you're lucky and pulled the power plug for a certain amount of time. That was always caused by defective electrolyte capacitors in the (build in) power supply. If the fault stems from the HX FX: There should be one big electrolyte capacitor on the circuit board close to the DC IN socket, probably a 1000µF 16V or something. That would be my no1 suspect to check for defect.

There is literally a CCToggle command in Command Center?! If you want a PC (program change) toggle try this: Use snapshots with Instant BankPC Command: Switch to Snapshot 1, go to Command Center and set Instant BankPC Command Program to #51, then switch to Snapshot 2, change BankPC Program to #55. Then you can setup a Footswitch (i.e. FS1) to change the Snapshots: Switch to Snapshot 1, go to Command Center and set Footswitch 1 Snapshot Command Press to Snap 2, then switch to Snapshot 2, change Snapshot Command Press to Snap 1. Now Footswitch 1 toggles between MIDI Program #51 and #55. You can then choose the bypass behavior of the blocks to not be affected by Snapshot switching if you want (press Action -> Snapshot Bypass On/Off). This obviously works with more than two MIDI programs or CCs, too.

From my point of view it's a hardware defect and you should open a support ticket. Great description btw!

Can you provide a link for the power supply you're using?

I use Inst level and do Low/High Shelf -> LA Studio Comp. Setting Low/High Shelf as +24dB neutral clean boost: LoGain +12dB, LoFreq 2kHz, LoGain +12dB, HiFreq 500Hz, Level +12dB This way the input level for the compressor is high enough to actually compress the way I want it to. Works great!

USB input 7 is a dry guitar signal. If you can select it in Midiguitar2 as the input signal that is all it takes to run Helix and the Synth in parallel. Alternatively you can use a DAW, create a track with USB 7 as input and load Midiguitar2 as a plugin.

Problem 1) Dark sounding guitars tend to sound muddy and fuzzy when distorted. Compare your guitar with your friends guitar. You could both plug in each unit ( at the same time even) and compare the sound. That would be my step one. Problem 3) Perceived tone loss usually is volume loss. If you set input and output levels to instrument and crank the volume knob you should have unity gain (input equals output level-wise) with an empty patch.

49C is the last preset of bank 1. Set bank CC00 to zero (instead of off) to switch to bank 0. Read the Tonex manual's MIDI specifications for further description if needed. Yes.

Threshold sets the input level at which the effect is swelled in or out. Attack determines how fast or slow the swell happens. If you want the note you pick to swell you need to make sure the note's level is high enough to exceed the threshold level AND that the level was below the threshold before you hit said note. Put a compressor or overdrive in front if the swell is too dynamic.

The DT880 is far from being neutral - see DT880 frequency response. Compare them to other headphones or studio monitors to get a feel of how they color the sound. Although you're using a reverb in the patch - when using headphones try adding a dynamic ambience. Otherwise it's like listening to a speaker in a dead room - it's too direct and irritating. You're right about the Katana's controls not affecting the power amp, it's neutral, one thing less to worry about. The Katana is an open back combo with a quite bright speaker. The cab choice you made in the patch is a 4x12 T75. It's great but not bright and has much thicker bass response (hence your 150Hz low cut?!). I like the speaker choice generally. My suggestion: try bring it closer to the Katana by using a parametric eq (in front or after the cab): 80Hz, 0.3q, -2.5dB, 2kHz, 0.7q, 0dB, 4kHz, 7.2q, +2dB. This is just an educated guess of a setting that I did by ear. I should lower the boominess and add an edge in the upper mids. Experiment with the values! All my comments ignore the Aviator's part in the sound - I don't know it and it would take too long to investigate. Lastly: when you lift an amp from the floor you loose bottom end. That is a thing to consider as part of the equation.

I think I can guide you to a place where the direct signal is a good representation of what you're hearing with the amp. This might become a longer process because there are lots of variables involved. I'm reluctant to write extensive posts - so let's go through the matter one step at a time. First step - narrowing down what you are hearing with your amp: What amp do you use "as a cab"? Does it sit on the floor? Do you tilt it at an angle? What's your listening position / angle with respect to the amp? If it has presence and depth controls: how do you set them?

It's a feature and it's AWESOME. It enables switching between snapshots in Footswitch mode. You need to set the footswitch for each snapshot. You can run through snapshots like 1->2->3->1 or 1->3->2->1. Or use two footswitches with 1->2->1 and 1->3->1.

Effects are categorized in Mono, Stereo and Legacy. The latter category is a bit of guesswork on the device. In HX Edit the stereo blocks are indicated with a symbol next to the name. Have fun!

You can tune the tuner using it's Reference parameter. You can use i.e. the Poly Shift with Interval 0 and Cents +50 (or Interval 1 and Cents -50) to shift from standard A to exactly between A and A#. You cannot change the Twin Harmony's note separation points/frequencies - it will glitch more with a non-440Hz tuning.

The preset uses a Simple Delay in mono.

Looks good so far. Check the Split and Mixer "blocks" for neutral panning. If that's not it: post the patch.

You need to use a Send L/R block instead. Send L uses tip, Send R use ring and Send R/L uses tip and ring.

You need to program this per snapshot. Switch to snapshot 2 and then edit the button to got to snapshot 1.

Balanced signal transmission has two benefits: Noise suppression - this is more relevant with weak signals i.e. from microphones. Possibility to lift ground. Ground loop hum can be annoying and lifting ground often is a fix. Transformer balancing adapters like Neutrik NA2 F-J-TX or Palmer DI-REVERSE are good solutions to get those benefits in your situation.