perapera

hi edstar1960 I'm sorry I don't have a lot of time to answer you in these days I'll try to be as clear and synthetic as possible first, you're gonna have to follow me on my schematics while you read here; second, what I'll write here is referred ONLY to the type of mono setup you described in your posts, which I think is the most commonly used by guitarists: guitar > POD HD500 > mono "monitoring system" (whichever you use) third, since you're using XLR outputs I will not consider the jack outputs let's start with a configuration that uses only one amp (no fx, nothing) starting from a default "new tone" just choose an amp model of your choice what happes is that at the split point the mono signal coming from the amp is splitted in FOUR identical signals which go to the left and right channels of path A and to the left and right channels of path B now if you leave the mixer at the default (100% L/R) and connect for example only the left XLR to a monitoring system you get EXACTLY the original "single" signal which is coming out of the amp model if you have followed the signal in the routing schematics you should agree the consequence is that, externally summing the two XLR, is giving you a doubled signal (BUT I must say that "Y cables" used for summing are everything but ideal; see here: http://www.gearslutz.com/board/geekslutz-forum/453415-wye-not-wye-combining-signal-y-cable.html and here http://www.rane.com/note109.html ) AND if you turn the pan pots into the pod's mixer to 0% you'll get another doubling of the signal now remember that our hearing system is NOT linear: an increase in level is perceived as a sound with more lows and highs and this is often described as "fuller", "warmer", "more open" but it's just level, my friend (and of course if it gets too much it can clip and become harsh) http://en.wikipedia.org/wiki/Fletcher%E2%80%93Munson_curves _________ frome here, if you add effects, things can be more complicated... ...but less than one can think for example (always follow me on the schematics): problem: if you leave the mixer at default and put effects on path B they will output only their Right signal to only the Right XLR which in our case is disconnected solution: turn the B pan-pot to 100% Left too! this "looses" the Right signal but this could only be a problem for some effects (ping pong and stereo delays, auto-panners, etc) which a person who wants a mono signal should't use, should he? ___________ sorry there is no "best" way to use the mixer I can only suggest to start from the default and experiment and listen... ...just like you did with the "amp pre-split vs post mixer" experiment: - you heard that at default settings (L/R 100%), it's the same so your choice should be based on if and where to take advantage of the parallel paths for special fx combinations - with the the mixer's pan-pots at center (0%) if A-Left, A-Right, B-Left and B-Right are all carrying the same signal and you put the mixer's pan-pots at center (0%) you'll double the signal, so moving the amp pre-split gives more level ONLY IF YOU SUM the L/R XLR's but not if you use the left only, while moving the amp post mixer gives more gain (distortion) _________ I'm sorry if I didn't discuss all possibilities but this should give you a lot of material to think about ;-) bye Lorenzo p.s. wow that wasn't exacly "synthetic", was it? :)

hi Milan I'd like to check your re-drawings before you publish them and I'd like to use them in this thread (of course with credits to you as the "digital artist" ;-) )

Hi Milan wow, I'm really pleased by your offer! yes of course you can You just have to mention me as the author I think you can write <<original schematics by Lorenzo Sempio, "perapera" on the Line 6 forums>> I'm particularly pleased cause I've been many times in czech touring as a sound engineer and I found many kind people, friends and music lovers ahoy! Lorenzo

thanks guys! it's good to know that I can be helpful to you! and to sjnewbold: check the input settings, but I don't think this is the case: the bypassed-amp vs active-amp level match is independent from the input settings and depends on the "channel volume" of the amp model (of course the master volume and drive affect the level too, but they also affect the tone) anyway, in my opinion, it's not something so important to care about: normally you do not "bypass" your real amp ;-) in your "guitar > pod > amp return" configuration the only thing that matters level-wise is that the return gets the right level for the power amp to work correctly (expecially if it's a valve power amp and you want to push it to get it's sound) so you just have to roughly match the level of your amp's preamp with the pod (with an amp active) example: - match a clean pod amp level with your amp's preamp clean channel (to do so use the channel volume of the amp model and the pod's analog output level and 1/4" out switch) - do the same with a crunch and lead tone (using only the amp model channel volume) - experiment with the output settings (Combo or Stack should be the way to go but only your ears will tell you) - then start building your patches in relation to that level bye Lore

hi ess765 yes the delay bpm also suffers from this problem, actually it's the bpm value saved into each patch that has the bug, so I think each bpm based effect is affected the hd500x has more cpu power not more memory slots, and I don't think this is an hardware issue, I think it's a software bug in the communication from the pod to the edit software (so it could be in the pod firmware and/or in the edit software) reading your issue, it could be that this specific patch has been somehow corrupted try this procedure: save you patch as a file on your pc (as a backup) send the patch from the edit software to the pod save the patch on the pod by hitting "save" two times disconnect the pod usb cable change patch with the footswitches and go back to the first patch was the patch saved? you could also try to send a blank patch on that memory location on the pod and save it to "reset" it and then send the correct patch anyway the point at which I came to is "do not use the footswitches on the pod while it is usb connected to the edit software" bye, Lorenzo

yes,brue58ski correct if you connect to guitar input and leave the default input setting (everything/same) [or maybe opt for guitar/same to avoid any possible noise from the mic in] you have nothing to worry what hurghanico adds is that if someone wants to use two instruments/sources with two separate paths they of course have to set different sources in the inputs settings (e.g. guitar/mic), and they also have to avoid mono effects in the pre-path or the separation is gone... this way they do not have to worry about any signal loss too

thanks Bobbo! you're right, in the pod LCD and Editor screen the single lines indicate stereo/dual signals; I'm writing this note just to clarify and help people who are reading my schematics and these posts: all meambobbo wrote in his post above is written and drawn in my original post/schematics in my schemes above every line is a single signal, so they are a lot more accurate than the Edit software or LCD representation, that's one of the reasons I drawn them. just by understanding and reading them you can really master the routing inside and outside the pod, in fact I personally look at them everytime I need to do some complex routing following the signal through them you can come to a lot of conclusions that unfortunately are NOT explained in the manuals including the so called "advanced" guide peace Lore

yes, they recently moved the old forum and didn't bother to set up some kind of redirection to make the old links work... (of course when I posted this it was working...)

yes of course you're right! :-) the correct phrasing would be "neither the mixer nor the XLR outputs have the ability to mix to mono" by the way, to mix to mono at the end of the chain, you could also use a noise gate with [0 decay; 0 threshold], instead of the fx loop; this way you don't have to use an additional patch cable bye Lore

sorry volkerwassermann that isn't true! Bushman2 was exactly right: "the XLR outputs on the HD500 never sum to mono" no matter what putting the pan to center is not going to mix anything to mono each path (A and B ) is stereo and the mixer "pan" is mislabeled, it's actually a balance knob of a stereo mixer channel this means that if you move the pan/balance to one side (e.g.: left) it acts on the stereo signal by doing NOTHING on that side (left) and ATTENUATING the opposite side (right) if you put it in the center it's just passing the left signal of the respective path to left out and the right to the right so in your application everything is fine, but you've got to know that if you use a stereo effect on path A for example and you pan it 100% Left you are loosing the right side of the effect (not that this is a big deal ) see my post here for a quick experiment that prooves that: http://line6.com/support/topic/2617-using-both-line-out-and-xlr-out/?do=findComment&comment=18005 and if you are interested in thoroughly understanding the pod HD signal routing, I invite you to read this post of mine and to look at my schematics: http://line6.com/support/topic/2033-pod-hd-500-500x-routing-schematics/

thanks man! and thumbs up to who is able to say "I was wrong": not so diffused on forums in general ;-) I think you should make an errata corrige of your statements also in the other topic here: http://line6.com/support/topic/2699-removing-dual-amp/ 'cos someone could make bad choices based on wrong information "thank goodness I like very much many sounds that I get with this machine, which comforts me and makes me forget (even if not completely) certain imperfections.." yeah it's the (in)famous love/hate relationship with that machine, I have it too ;-)

sorry guys to say you're off topic with the timing issue... ...now, to tdownerd me too, I'd like the loop volume to be assignable to the exp pedal or at least a "fade out when stopped" option please vote this function on IdeaScale here : http://line6.ideascale.com/a/dtd/HD500-Looper-volume-should-be-controlled-by-exp-pedal/490433-23508

sorry hurghanico, you are wrong ;-) try this: take a blank patch mute path B put a ping pong delay on path A listen through the xlr left out listen to it with the A channel "pan" to 100%L or center: nothing changes: the right part is gone (you hear an eighth note and then quarter notes) (p.s. the "pan" is mislabelled, it's actually a balance on a stereo channel) now want another proof? put a noise gate (decay 0, threshold 0) after the delay and you'll have the real mono summed signal (which sounds like a normal delay) hurghanico said: "if it wasn't like this, it wouldn't be possible to get 2 complete separate chains signals (L + R summed to mono for each path) one on the Left and one on the Right, and all that without worrying if to use or not stereo FXs in each separate chain" that's a good point hurghanico, but it's like this: it is not possible; if you use 2 different sources for guitar and aux inputs and pan the A to left and the B to right you have two mono separate chains with "left only" or "right only" fx but again you only loose marginal things... (and anyway the ping pong delay in "left only" sounds cool doesn'it?) peace Lore

1) in short the answer to the OP is: > Hi, Hi man ;-) > if i only use 1 xlr out, i will get a mono signal, yes and no... if you have a mono signal inside the pod, yes you have a mono signal if you have a stereo signal inside the pod and you use the XLR Left out, you will loose all the Right side is that a problem? well, see below > but if i connect a 1/4" cable to my stage monitor live, while xlr runs to the house PA, will it still be mono in both outputs (since im using 1 of each)? Will the signal be the same as running only 1 cable, or will the signals be overidden by each other? the jack and XLR signals are independent of each other so connecting a jack doesn't affect the XLR signal (what I said about XLR's still applies), but if you have a stereo signal inside the pod the jack signal will be a mono sum of the Left and Right so it will be different from either the Left or the Right XLR §§§ 2) a more detailed answer: first of all, if any of you are interested in thoroughly understanding the pod HD signal routing, I invite you to read this post of mine and to look at my schematics: http://line6.com/support/topic/2033-pod-hd-500-500x-routing-schematics/ then there are some points I needed to claryfy on things asked and asserted in this discussion: - mono sum => NO signal boost even if you have a true mono signal into the pod, using only one 1/4" out will NOT give you a louder signal; the pod correctly attenuates by 6dB and sums the L and R signals any time it does a mono sum - if you have a true mono signal at the end of the pod signal chain, using an XLR or 1/4 jack out doesn't make any difference and you should choose based on what are you connecting to (the 1/4 jack has a hotter unbalanced signal, while the xlr has a balanced mic-level signal) AND you can even use all 4 outputs to go to different destinations with exactly the same sound (but different levels) - so now what do I mean with "true" mono signal? well a mono signal is simply a single signal, full stop. but since all pod internal signals are dual, in the case of the pod we are talking about a pair of signals wich are exacly identical, we could call it "double mono". now, you said you wanted to keep your patches as mono as you can: that's a good idea so, how you get to have 2 identical signals on the Left and Right outputs? on the pod hd you can start with an empty patch, leave all the defaults as they are, only use mono effects and do not use A/B paths (or if you use them, pan them to center) or do anything you want and then put a unity gain non-colouring mono effect block at the end of the chain (the noise gate with 0-0 settings is the one to go); notice that this makes sense ONLY if you want to use a single xlr output) - phase issues: if you do not use path A and B, phase issues given by a mono summing can occur ONLY on: . the tail of a reverb (and only in the tail) or . the wet part of stereo modulation effects (not on your dry signal, only in the wet part, so just reducing the mix value, where applicable, can reduce possible problems) (of course in such a situation you wouldn't use stereo and ping-pong delays... would you?) you really have to decide by yourself listening to left only (or right only) and mono sum: if you do not hear a degradation then it's not there; how to do that? Here it is: mono summing: phase issues test method . connect a jack from the left 1/4" out to an amp or whatever you use . play (or record a loop with the looper, but this must be in the "pre" position because the looper at the end would sum to mono the recorded signal ruining the test) . alternately plug and unplug a "dummy" jack in the right 1/4" output . now listen for any difference in frequency content and level (is it thinner? boxy? dulled?) - now if you hear a difference and you don't like the mono sum, you could follow hurghanico suggestion and use a "left only" approach by putting everything on the A path, panning it to Left, muting path B and using the left jack and the left XLR that would give you exactly the same signal on both XLR and jack left outputs and no phase issue but would loose any right signal (again only half reverb tails and half modulations), and you decide if that's a problem, for me it's not §§§ 3) line 6 line 6 has never showed to care about complex signal routing issues, so my guess is they will not "weigh in on this discussion", dear sbeattie7 they never said NOTHING about my signal routing schematics even if I asked them directly, both on the thread I initially posted in the old forum (http://line6.com/support/thread/90441 ) and through private messages to the experts and gurus notice that luckily I re-posted my schematics and conclusions in the new forum (http://line6.com/support/topic/2033-pod-hd-500-500x-routing-schematics/) because now the old forum is archived and it's NOT reachable from the support menu on the line 6 homepage (by the way it's now here if anyone is interested: http://line6.com/supportarchivenew/) and it's impossible to reach with the old links and it's not searchable from the new forum (well you can search but the links are wrong!) and even if you get there (maybe through google) the archived version has no images and the links to the images are not working well... sorry for the rattling ;-)

I read your amp's manual and I must say the fx loop thing isn't too clear: "The EL DIABLO is designed with a serial effects loop. The effects loop is a post master section loop and is an ideal place to send the entire preamp signal out to another amp using only the send jack, or to insert a global effect such as a compressor (serial effect) or a digital effects processor (a serial effect when used with the processor’s own “wet/dry†mix control). The return is also a handy input for connecting the power amp stage to the output of another preamp or signal source" the two sentences I bolded are clearly in contraddiction with one another: the master volume of the amp should clearly be after the return not before the send... ...so this is the volume control you must use to get the desided reharsal level and you should definitely use the output switch of the pod on "line" position

hi parkinthepark! and thanks for the quote ;) please note that I reposted the fx loop level problem here: http://line6.com/support/topic/2040-pod-hd-500-the-fx-loop-attenuates-the-signal-at-the-send-jack/ this post is much more complete and clear I think, so could you edit your link, please? thanks now, on your main question, I think that "post-master" fx loop could be the thing generating the problem, anyway try out any (or all) of these: - flip the pod 1/4 output switch to "line" - pan both mixer channels to center - rise the mixer faders - discard my "return +8" suggestion so that your preamp will sound quieter p.s.: and by the way, if you have time, read this thread of mine about using the looper to match levels: http://line6.com/support/topic/2034-the-hd500-looper-could-attenuate-the-recorded-signal-by-6db/

done here: http://line6.ideascale.com/a/dtd/HD500-bug-mixer-faders-not-saved-with-send/529219-23508 please vote for it!!!

yes you're right... .. I followed the contact us link and the feedback on products seems now handled by the new IdeaScale thing, do I have to register on that?

I found exactly the same problem and exactly the same solution on my own: If you change mixer levels on the edit software and then "send" to the HD500 those changes are not saved untill you also press the save button on the HD500 itself, so I confirm what jahardo said anyway the problem only occurs to the mixer settings, no other setting that I'm aware of is affected also I'm not shure if the thing appens every time I edit the mixer settings

I can understand your frustration I personally use two signal chains in parallel one of which includes the fx loop with a valve preamp with speaker simulation (AMT SS-20) in it, using only one amp module in the pod frees up DSP power and enables me to use all 8 fx blocks

yes this is what I ment with "use the mixer as a boost" but 12dB is A LOT as HarryN noted 5 or 6 dB should be more accurate to send the right signal to external equipment anyway I don't like this solution because it restricts too much the routing options for my use of the unit

in the POD HD500 the fx loop block is LOOSING 5dB on the send with the switch in the "stomp" position. (I don't have a POD HD500X and it would be nice to know how it behaves on that, but I suspect it will be the same or Line6 would have advertized it...) this means that, if you connect anything gain related (compression, distortion, preamps, envelope followers) into the fx loop you're getting the *wrong* gain result of course, also the very popular four-cable-method (http://line6.com/support/docs/DOC-2504) is seriously affected by this problem! this is something couter-intuitive and *guiltily* not stated anywhere in the manuals. • Before explaining the details and giving some possible solutions to the problem I have to say that many other threads (on the old forum) have talked about this matter, including one of mine; those posts received many replies and integrations, so what I'll write here is my experience largely improved by all of those posts some examples: http://line6.com/support/message/393494 http://line6.com/support/message/397759 http://line6.com/support/thread/90441 (point 2) • Now let's see the details: what I (repeatedly and professionally) measured is that, with the stomp/line switch on "stomp" and input pad on "normal", the guitar signal is attenuated by 5dB (approximated with no decimals) along his route from the input, thru no fx and then to the send jack, and then it is partially compensated by a boost of 4dB at the return jack; [this additional 1 dB difference (again approximated with no decimals) from -5 to +4 is even more inexplicable and could be only on my POD HD 500 unit, so you'll need to test your own; but many users confirmed the problem] furthermore, as you may know, the stomp/line switch set to "line" gives (correctly) 12dB to the send AND compensates that by attenuating the return by the same amount, but the line position is "suffering" from the same -5/+4 attenuation/compensation, so you actually get +7dB at the send (+12 -5) and -8dB at the return (-12 +4) as a result; • I can only guess that a reason for this -5/+4 attenuation/compensation could be to put the fx loop block "unity gain" at approximately half-way between a stomp and a line reference level, but this choice is wrong (or at least badly implemented and guiltily not documented in the manuals) common sense here: when I connect my guitar directly to any guitar input (stomp-box or preamp) I have a "stomp" signal level, so: - the stomp position of the switch should definitely be at *real* unity (=same level as the guitar itself) - consequently the "line" position should give +12dB on the send and -12dB on the return - then we should have the ability to give or take some dB's on the send as well as on the return via some software trims • furthermore, if you connect a cable to just one of the fx return jacks (this works also with the Right return, not only the L/mono) the fx loop block acts exacltly like a mono fx block, so it attenuates and sums its inputs and then sends the result to the send jack (to both pins of the TRS jack to be precise), and then splits the return to both outputs of the block IMPORTANT: you need to read this thread to understand what I'm talking about: http://line6.com/support/topic/2033-pod-hd-500-500x-routing-schematics/ this means that if you are using the [input-1: guitar / input-2: variax] setting and you put an fx loop in default mode into the "pre" path with for example your amp's preamp into it, you are loosing 11 (or 12) dB of gain!! • SOLUTIONS 1) "line attenuated" solution - set the stomp/line switch to "line" - use the fx loop with these settings: send: -7 , return: +8 (these values could be precise only on my Pod HD 500 machine, but the order of magnitude is this) and you'll you get the right gain and level (unity gain) AND you can boost or attenuate the send AND the return level if you need it! BUT (and it's a BIG BUT) you'll get more hiss than what it should be (getting more gain always gives more noise of course, but this is added on top of that) I tried the stomp and line positions of the fx loop switch, compensating in various ways to their boost/attenuation and the stomp has always a little more hum while the line has clearly more hiss this has no explanation but is confirmed by many other users 2) "minus two fx-blocks" solution - set the fx loop switch to "stomp" - set up this routing: . a tube comp (settings 100% , 17%) giving +5dB before the fx loop . the fx loop with default settings (send: 0dB and return: 0dB) . a fixed volume pedal (at 78%) attenuating by -4dB after the fx loop that gives you the correct gain and level (unity gain) but with a lot less hiss than the "line attenuated" solution [note: I called this the "minus two fx-blocks" solution, even if it's not totally an idea of mine, because it's easier to recall; actually this is a variation on the solution offered by Jim Reynolds here: http://line6.com/support/docs/DOC-2522 at point 4 of the "Patch Setup - Effects Only" section but I found that even if the "studio eq" gain pot is labeled in dB's, the numeric values are wrong (to have a real 6dB boost, you need to see "8dB" on that pot); furthermore, the studio eq and the tube comp are both intentionally clipping the signal to emulate their analog counterparts and I found that, with my setup, the tube comp has a better sound] • of course it is (at least) ridiculous to loose two fx blocks to compensate for a hardware design fault (I don't think the -5dB send level loss is a fault in my specific unit because many people have found the same problem) and of course, depending on your fx-chain into the pod you could: - use the mixer as a boost OR cut and loose only one fx block - use other effects (which must include a volume control) that you normally leave always on, as a boost and/or cut - use some external analog clean boost and attenuation - compensate with your amp gain and volume controls but anyway you put it, each of these solutions ends up as a workaround that the pod needs to let you do a simple thing • in the end I actually chose a variation of the second solution: I use the switch on the stomp position and a tube comp with threshold 100 and level 17, BUT I decided NOT to compensate for the +4dB given by the return circuit or I would have to loose another block; so in the end it's a "minus ONE fx-blocks (partial) solution" ;-)

you're welcome!

the HD500 Looper could attenuate the recorded signal by 6dB ... ...depending on your routing and settings. (all of this should be valid also for the POD HD Pro and bean, but NOT for the POD HD500X since its looper routing is different) The point can be summarized saying that the Looper is a "mono wet / stereo dry" fx block; you only need to be aware of this if you use the looper in "pre" position and you are one of those who think it's better to disable input-2 (for example by assigning it to variax) also, please, understand that what I'm trying to explain here is complicated so start reading only if interested, thanks to understand what I'm talking about, you need to read this post of mine and follow the signal on my graphs here: ...so, getting to the point: "the looper is a mono wet / stereo dry fx block" means that if for example you have a situation like this: - guitar connected to guitar input - Input-1: Guitar / Input-2: Variax - Looper in "pre" position - no fx - Amp Block in Path-A (path-A at unity and pan centered, Path-B muted) and you record a riff in the looper, the looped level will be 6dB less than the original signal! explanation: as a "mono wet / stereo dry fx block" the looper attenuates his inputs and sums them, then it records the result and, when playng back, sends the recorded signal to both his outputs so if you have disabled input-2, your recorded loop will have 6dB less than the original signal and will be splitted to outputs 1 & 2 of the looper, WHILE your dry signal will be present only at the output-1 of the looper now, if the first mono effect you have is in path-A, the mixed dry and -6dB looped signals from output-1 of the looper will be splitted to Left and Right channels of path-A and that mono effect will receive them at both its inputs otherwise, if the first mono effect you have is in the pre path you will hear no difference between dry and looped signals: indeed the looped signal will re-gain its lost 6dB because it will be present at both inputs of the effect (while the dry is present only on one input). so, to summarize: if you have Input-1: Guitar / Input-2: Variax and the Looper in "pre" position: 1- if the first mono effect is in path-A, it receives the dry signal at unity and the looped one at minus 6dB 2- if the first mono effect is in pre-path, it receives the dry and the looped signals both at minus 6dB consequences: This meas that, if your purpose was to have the ability to tweak your amp settings while listening to the results on the looped riff, and your amp is in path-A, you're going to get the wrong gain setting! (because you will be pushed to turn up your amp drive pot more than needed) Now, in the same situation (even while your riff is still looping), if you move your amp in "pre" position the loop will play at the same level but the dry guitar will play less distorted! solution? set both inputs to guitar (before recording the loop), and none of this problems will occur

I posted this in the old forum months ago, since many peole found it useful I thought I could re-post it here: ___ I really think these are important things not stated (or in some cases not clearly stated) in the manual, that you need to know to start seriously programming your POD HD I ran some serious tests on my Pod HD 500 and here is what I found out (I made my tests on a POD HD500 but this is valid for HD500X and HD Pro and is very similar for the "bean" version too), I'll try to be as synthetic (but complete and clear) as possible, but this is going to be a long reading so sit down and take your time or just go surfing somewhere else §§§ In short: the "famous" [input-1: guitar / input-2: variax] setting gives you different levels of signal depending on the position of the first *mono* effect block you use (amplifiers included), in particular you LOSE 6dB in the "pre" path in comparison to the path A/B or post path (note that this is not the same as saying that you gain 6dB with input-2 to "same", read on). [ if you don't know what I'm talking about just go and read this thread: http://line6.com/support/thread/74045?start=0&tstart=0 then come back here to hear a different opinion on the matter] first of all, try it out: - connect a guitar to the guitar input and the Left output to a full-range linear amp (or use your headphones) - recall a "new tone" default blank patch - set input-1 to Guitar and input-2 to Variax - set mixer channel A fader to unity (0.0dB) and pan to center - set mixer channel B fader to mute - setup a noise gate* with the threshold set to 0% in "pre" position (with this setting this IS a unity gain mono fx block) - play thru it - now if you bypass it, you'll hear that it looses 6dB of level when it's active (I initially thought this was noise gate's fault, but it's NOT) - now re-activate the noise gate and move it in A or "post" path - now if you try to bypass it you'll hear that it does NOT loose any dB - try moving the block back and forth between pre and A or post paths and you'll hear more level in path A or post than in pre this was already found out at least by hurghanico here: http://line6.com/support/message/403287#403287 but it's so important that needs a dedicated and more detailed thread. [* you can repeat the experiment with other mono effects instead of a noise gate but keep in mind that, if you want to clearly hear a level difference, you need a mono unity gain (www.music-dictionary.org/unity_gain) effect, for example: - a tube comp with thresh 100% & level 2% settings will work just as the noise gate above - an fx loop block with a mono cable connected between send and return will work just the same (but also read point 2 below) - do it with an amp with medium-low gain and, moving it between pre and A or post paths, you'll hear a significant difference in gain/ovedrive/distortion, not only level difference] §§§ OK now that you heard it, let's see it in detail; these are the REAL schemes of the pod and fx blocks routing, yes it's done by hand and I love it ;-) As you can see the pre path is a "dual-path" while A, B and post are all stereo paths; at the splitting point, where the path A and B are born, the signal coming from input-1 is splittted to the Left and Right channels of the path A and the signal coming from input-2 is splittted to the Left and Right channels of the path B; furthermore all fx blocks have TWO inputs and two outputs and the mono blocks do attenuate by 6dB and sum their inputs, then process the result and then split their mono output to both outputs of the block; for those who don't know, notice that: - "splitting" means duplicating one mono signal to two "routes" - and summing those two identical signals means doubling the level of the original signal (which equals to 6dB more) [and some side-notes: - the "stereo dry & mono wet" effects are for example the pitch effects and the "dry" type delays, I'm not considering this type of effects in this post, but they work as expected from the scheme you see above; - you can find a list of all the fx blocks divided by type here: http://line6.com/support/page/kb/_/pod/pod-hd/stereomono-fx-list-for-pod-hd-r567 where "stereo dry & mono wet" blocks are called "Stereo Thru/Mono Effect" which I personally find less clear - the mixer control named as "pan" is actually a "balance" control because if you move it to one side (e.g.: left) it acts on the stereo or dual mono signal by doing NOTHING on that side (left) and ATTENUATING the opposite side (right)] §§§ So, summarizing, if you only activate input-1, in the pre path, the first mono effect is attenuating the input 1 and 2 and summing them, but, since input-2 is actually silence, you loose 6dB; in A, B and post paths the effects are receiving a doubled signal on L/R, so the mono blocks, attenuating and summing the two signals, receive the right signal level to process so using "same" or "guitar" for input-2 does not mean to gain anything, but having a constant doubled signal wich is compensated by a 6dB attenuation in each mono summing it encounters in his flow please note that I am NOT saying that using only input-1 is wrong, you just need to know that this can give you different gain results depending on the position of the first mono effect with only input-1 active (Guitar/Variax) and the same parameter values, this: is giving you more distortion than that: now, if you use those two setups with "Input-1: Guitar / Input-2: Same", you get EXACTLY the same sound with both and this is something that can not be ignored ...don't know how to be more clear than that