zolko60

Not really.  In my method MIDI CC# are maped to Helix plugin automation by Reaper. Reaper learns what you teach him. It was 1.5 version of HxN with no midi support. It is however good to know if and what CC data are transmitted from floorboard. For this purpose I use small, old Midiox utility. There should be some alternative for Mac users as well.
HxN v1.6 and up brings more (redundant to my method) possibilities by adding MIDI control directly to the plugin.
In my case changing snapshots with built-in midi does not work cause my floorboard switches can not transmit CC values other than 0 or 127.
I thought that maybe built-in MIDI could be transmitted out of the plugin for changing fb switches state (reverse action and ilumination) after changing snapshot or preset but manual states that all "Command Center" functionality is disabled :(

Sure, but what exactly does not work when you try to set it up following my first post?

That might be your diy made IRs are exceeding 2048 samples. Try to load them in some sample editor and check. They can be edited like other wav files.

No matter what I do Ableton 10 is not able to see HxN plugin (Windows10). I install HxN to Program Files/Vstpluging folder. They reside in ProgramData/Line6/HelixCore folder. HelixCoreWin_x64.dll and HelixCoreWin.dll. Other VST programs can find them, Ableton can't.
Yes I tried to copy them to Vstplugins folder - no luck.

They are not actually Program Changes. You can automate Raper FX Preset Changes this way.
Explained there: https://line6.com/support/topic/32014-helix-native-and-reaper-working-floorboard-live-rig/

Yeah. Line6 GUI designers!
There is plenty of space above the DSP block icons. Why not make "LED indicators" attached to the icon there?

Sure but only variable CC device I have in TLLE is one pedal which I need for other functions. No problem - two snaphots by toggle switch are good enough.

One and only serious "issue" of SAVIhost is it does not handle plugin automation at all :(

There is a litlle drawback in using Reaper "FX Presets". They are in fact "snaphots" of the plugin and instead of loading HxN patch they load saved plugin state.
It means if you make any changes within a patch and save them in HxN, you have to save Reaper FX Preset one more time.
Take care!

Nulls to zero? On different DSPs? Complete Zero, Null, Nothing? Sounds incredible! I always thought different processors would give slighty different solutions.

Not for me :(
Calling HxN subforum still returns an error.
I tried from two different IP's.

There is always some workaround. You can build 1/2 note delay from three 1/2 triplets. :D
(joke) 

Funny thing is I can read last topic on Helix Native subforum http://line6.com/support/topic/32313-hardware-for-native/?do=findComment&comment=248494
called from page http://line6.com/support/forum/29-computer-based-recording/

but caliing HxN subforum http://line6.com/support/forum/90-helix-native/ returns an error 502
<h3>We're sorry.</h3>
<p>There seems to be a problem with the page that you've requested.</p>
<p>Please try again later.</p>
 

So if anybody prooves such a phenomenon exists, somebody will have chance to spot it.
Let's treat it as non-existent until then;)

How rare is that issue? Do you experience such cases? In what circumstances? 1/2 note is higher value than 1/2 triplet or lower?

Can you adress any topics about "delay pitching issue"? You mean "glitching"? http://line6.com/support/topic/29514-delay-glitch-when-choosing-another-snapshot-with-different-delay-time/
I actually love that glitch when changing snaphots :D

Tap Tempo in Reaper with midi CC switch:
- Open "Actions" menu
- In "Filter" field type "Tap" and choose "Transport: Tap tempo"
- Presss "Add"
- Tap your MIDI Switch, click OK
- Press "Run/close"
- In HxN upper right corner change bar icon (Per Preset) to watch icon (Host Sync)
- In delays you want to tap, change "Time" to "Note Sync by pressing watch icon
- Use dotted 1/8 to mimic The Edge ;)

DONE

Link not working.Here's the message I get :

error: Invalid 'page' requested (only number > 0 allowed).

I am so sorry!

Please click "Customtone" above the error message and choose one of Helix items.

It is 2018, XXI century. Still Round Trip Latency RTL is a mystery and hardly interface makers give it as SPEC POSITION. I know it depends on whole lot of factors but:
- there are typical Windows and Apple laptops, desktops - even if one has different machine, results are comparable,
- there are typical audio optimizations for specific operating system,
- there are typical DAW's and audio hosts,

You don't need to rely on software RTL reports or install "RTL utilities". Hooking cable to one input, routing output from DAW track another input (loopback) shows whole RTL for given interface - YES, it is so easy!
Judgment if system is stable and audio artefacts free does not have to be subjective opinion neither.

Line 6 guys - please consider!

There is indeed some problem with snapshots which could be called a "bug".
If you assign automation for DSP block prior to its bypass state in other snaphots, their bypass state is neither remembered nor stored.
The workaround is to assign bypass back to default "None" then make bypasses in other snaphots and then reassign bypass automation to "Switch". 
My setup is Win10 i5M laptop, NI KA6 interface, Reaper 5.62 hosting HxN 1.5 and Vox TLLE as MIDI controller. 

Yeah, if you happen to have interface with >120dB dynamic range and low noise, maybe leaving 18dB headroom is good idea but...
...if you have just budget small USB powered box:
- bang your loudest guitar as strong as you can and set input level (at peaks) just under the digital ceiling (0dBFS) - it will give you about 10-20dB headroom in "regular playing" unless you are extreme heavy hitter.
- if you really experience that your virtual amps gains are set lower comparing to real ones, just lower HxN digital input volume. 

I am trying to avoid more than 20 plugins in digital chain and more than 5 stompboxes. Having 5 guitars (including Variax) instead of 20 sounds like a good minimalistic idea :D

Still in shock how nice it works!
Looking for workarounds of some drawbacks I have mainly due to my floorboard limits I have found these plugins: http://thepiz.org/pizmidi/
I have not tried them yet but they promise to translate various midi (or audio) actions to different ones. If you can imagine for example changing any HxN wah to autowah using Audio2CC 

Free, vst host and OS independent (most of them) http://thepiz.org/plugins/?p=pizmidi

Don't give up! Isolate a problem. If you are having fun in replacing amp tube preamp with Helix preamps, use passive loop switch and check how the noise and sound behaves while switching a real thing to emulation. I would be glad to read/hear what the comparission is (soundwise and noisewise) on similar (virtual vs analog) preamps.
Do the same with fx loop - I mean helix in your amps fx loop vs pair of cables. I am even curious how a pair of Helix AD/DA converters alone in the path compare to a pair of cords.
Please share - it can be important.

Yeah, I know such a "modular thinking" is not popular ;)

Yes, Helix presets are compatible between all Helix platforms. Here you go: https://line6.com/customtone/browse/helix/