- internal clipping is surely possible but not at default settings and only using one amp (being it at default settings too),
in the test above, if the guitar doesn't clip the A/D converter (you can hear it with all amp/fx bypassed), then using Guitar/Same will not clip;
If engineers at line6 designed a dual path unit which, at its default settings, is unable to receive the same signal on both inputs, without internal clipping, they would be crazy or unqualified (if you start adding eq, comp, etc of course you can clip it)
- my understanding of the POD HD500 routing, as explained in my schematics, simply says that the "normal" level to send to the first effect is with both inputs active (Guitar/Same),
this is proved by the fact that putting the same distortion/amp in the pre-path or in one of the dual paths gives the same distortion ONLY if the inputs are on Guitar/Same (see the last part of my original post, which has been edited to be even more clear);
as I already wrote, this doesn't mean that using only one input (Guitar/Variax) is wrong,
on the contrary, it is perfectly reasonable if you want cleaner tones:
it gives exactly the same result as adding a fixed volume pedal at -6dB, but it's better, because you don't waste an fx block!
in the same way you just can't say that using both inputs is wrong or that it's causing problems on its own (unless you prove it);
on the contrary, if you want to use a dual amp setup and you choose only one input (Guitar/Variax) then you have to waste an fx block (noise gate 100%-0%) to send the signal to both paths!
This doesn't make sense to me at all
(unless you need to attenuate the input because the amplifiers' drive pots are already low but you want an even cleaner tone from both amps).
- we arrived at the point that many people think to solve the so called "problem" of the two inputs by giving away their ability to use two signal paths and putting every effect (and amp) on path A only!
This choice is unfounded for 2 reasons:
1- you have a machine able to do complex routing and you give this possibility away because you think it is flawed (if it's true, return it)
2- worse: by putting everything on Path A, you are actually sending to your effects exactly the same signal * as if you did put everything in the pre path and select Guitar/Same so it just CAN NOT sound different, but, as someone else said that not using input-2 and path-B sounds better, you just do it without properly testing it and against the default settings of the unit
I'm aware that all of this confusion comes from the official documentation: I think that the manuals are guiltily incomplete on purpose, to avoid to make you think that it's a complex machine because it has a complex manual.
that's why I posted all of this: to explain how this unit really works to people who are interested in using it at it's full potential
* look at the last 2 pictures in my original post
if you use those two setups with Guitar/Same you get EXACTLY the same result
if you use those two setups with Guitar/Variax you get less distortion in the second one