• first of all I must say that my intent here is NOT to tread on anyone's toes
I just don't like when an idea, not founded on reality, begins to spread and everyone thinks it's the truth, while the facts say something else
• the background:
many users in this and other forums reported the same "feeling" that something is wrong when using the default Input Settings which means selecting the same signal for input 1 and 2 (I'll refer to this as "guitar/same" o "both inputs active"):
according to them, this setting introduces some artifact which I'll call for simplicity "the input settings phase issue"
as a consequence they say that by choosing guitar/variax (therefore "disabling" input 2) you get a better tone
(of course if you use a variax you must "translate" what you read, the point is: if you are using only one instrument, should you choose its input for Input-1 and "same" for Input-2 or not?)
• I never read more than personal opinions on this matter and no "scientific" tests and of course simply switching between one or two inputs in the same patch is not even to take into consideration due to gain differences
so I decided to run those tests by myself
• even before testing I must say that, if the phase issue between input-1 and 2 was true, then it should be ascribed to a serious bug in the POD HD signal routing
"both inputs active" is even the default setting so it should work as expected
• if you're interested in the POD HD signal routing and to take full advantage of the possibilities of this machine, please take a look at these routing schematics I built months ago based on many tests:
• and finally the real point of this post:
I tested the difference by ear with a guitar and a looper before the pod and did not hear any difference,
then I tested it in a professional way and confirmed that THE ONLY DIFFERENCE between guitar/same and guitar/variax Input Settings is the level that the first effect/amp in the pre-path will receive.
So choosing guitar/variax is not "better" than guitar/same, it's just a good way to lower the input level and so reduce the distortion/saturation of your first effect/amp in the pre-path.
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 post here:
as I already wrote, this does NOT 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 simply no one can say that using both inputs is wrong or that it's causing problems on its own (unless he/she proves 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 (e.g. noise gate 100%-0%) to send the signal to both paths!
This doesn't make sense to me at all.
• I did the tests with a BC Rich Mockinbird with a DiMarzio Super Distortion on the bridge position, mounting GHS Boomers 11-50: not exactly a quiet signal...
and I didn't even have to insert the input pad of the pod;
so for me no clipping is caused by the use of both inputs alone at least for the effects I used in the tests
of course, for example, the studio eq and the tube comp have a relatively low clipping threshold with respect to the POD internal routing BUT it is a simulation of an analog clipping so it's an intended effect!
and again I've got nothing against the usage of the single input if you want to put one of those effects as the first and want it to be cleaner but please then do not crank the output of the effect or you'll be back to the start!
• last but not least, please if you are confused by the routing do not think that you have to use the "path A only" solution (putting everything in path A, center its pan and mute path B ),
you will get exactly the same tone and simplicity by using the defaults
to be more detailed:
- start from the default new tone (maybe switch the inputs to guitar/same jut to avoid any possible noise from other inputs)
- use the amp in the default position (pre split)
- if you don't need the parallel A/B paths simply do not touch them or the mixer
- put the pre effects like distortion in the pre path
- put the post effects like reverb in the post path
and you'll be perfectly ok
this should be written in the manuals, and in part is is,
I needed to clarify it
• for those of you who are interested, I created a setlist with the patches I used for testing, so that you can hear for yourself;
in a note inside the zip file, there are the descriptions of the patches and of the tests I did
• some amplifiers/fx models can have a slightly different sound thanks to an attenuation to the signal sent to them independently from their drive pot position (maybe because there is some pre-drive-pot circuit ?!? thanks to gckelloch for the idea)
this attenuation can be obtained with the "single input" setting only if your amp/fx is in the pre path, otherwise you need a workaround
read here for more details:
good reading/testing and