perapera

hi, I totaly understand your need to have the same amp parameters sound the same on a single path or on a dual path with an A/B split-switch you came to the right solution, but may be interested in this anyway: cheers Lorenzo

hi guys first of all I'd like to let you know that I read all the threads I found about this same subject and didn't find the complete answers, so I decided to run some tests myself (like I did on the POD HD years ago) and to create a new thread with my results (I'm on FW 2.60 by the way) ok, I'll start from the end results, so that those who just need to have a quick answer can read it immediatly, then I'll give some deeper explanations the main point of this post is: the moment you create a split/merge routing configuration by dragging down a block you get a level change: after the merge block, with all bypassed fx: with split A/B and Y you get +3dB at the output sum with split crossover you get -3dB at the output sum BUT each path by itself gets attenuated by -3dB so if you use the split A/B to switch between sounds, each of those sounds is -3dB qiueter than the same fx/amp with the same settings in a non-splitted path the good news are that the level changes do not actually occur at the split, so the two paths are both an exact copy of the signal before the split, instead the change occurs at the merge block so the right solution is to act on the merge mixer faders --- why? and why those values? • well to answer, I need to clarify two things that I've read someone get wrong and mixed up in other threads 1) when you sum two identical signals in a circuit either analog or digital you get +6dB boost (voltage sum) 2) when you send a signal to a physical speaker and then send the same identical signal also to another identical speaker you get +3dB (acoustic power sum) this is math and physics, not an opinion now, this second point is one of the reasons why something called "pan law" exists: as we said, when you have a mono signal going to two speakers (so the pan knob on a mixer is at the center position) you get +3dB of sound pressure so mixer designers in some cases decided to pad the center position of the pan knob by -3dB, gradually returning to unity gain at the extremes (in some other cases they may use -2.5, -4.5 or -6dB: the actual effect of the pan law depends on the coherence/incoherence of the signals, on speaker placement, on listening conditions, and also on mixing taste I would say, so the designers have to make an assumption and take a plunge, I don't have time to enter into this now, sorry). • now back to the Helix: you have an empty "new preset" patch you have a signal going through path 1 (I used various sine waves and pink noise) you add a gain block at 0dB (if you want you can even bypass it) => nothing changes you drag the block down creating a double path => you get +3dB at the output sum so, what's going on? - the A/B or Y split duplicates the signal to two paths, so each of them carries the same identical signal which goes to a merge block mixer channel, then the two get summed together... so you should get +6dB, but... ... since the pans in the mixer have a -3dB pan law you only get +3dB - the crossover does not duplicate the signal but splits it in two frequency bands, if you sum those two filtered signals you get the exact same signal you had before, so no +6dB boost here, but there is still the pan law, so you get the -3dB - but, as I wrote before, each path by itself gets attenuated by -3dB because of the pan law, so if you use the split A/B to switch between sounds, each of those sounds is -3dB qiueter than the same fx/amp with the same settings in a non-splitted path • please note that these are not theories or speculations, I've tested and measured thoroughly every configuration and I'm sure the Helix routing works like that • all this behaviours occur identically to mono or stereo signals, remember that all the lines representing signal flow in the Helix display are always "double conductor cables" so either stereo or dual-mono (stereo = they carry two different signals; dual-mono = they carry two identical signals) this point could be deepened a lot but I don't have time for this now --- some other considerations: • if for example you open the pan pots of the merge mixer to the extreme L and R, the pan law attenuation does not apply and the level goes back to unity BUT this is not a solution, because if you run in stereo you only get the left from path 1A and the right from path 1B • I'd like to warn you of potential problems I found with the parameters inside the split blocks I) the split A/B "route to" parameter is a balance control, not a crossfader, so moving it to the left attenuates the signal going into B while not touching the signal going into A and viceversa; so it is appropriate to use that parameter to switch from A to B but not too much to find a mix of A with B for 3 reasons: 1- as I said you only have control over the attenuation of one of the two signals you are mixing 2- at center (even position) you have more level than any other position because the two signals are at full level, so the judgement on which is the best mix is compromised for psychoacoustic reasons 3- worst of all: if the blocks in the paths are amps or distortion boxes or compressors, as long as you are not in A100, "even" or B100 positions, you are sending an attenuated signal to one of them, changing its sound and not only its level II) the split Y "Balance A" and "Balance B" parameters (added in fw 2.10 so not covered in the manual) work like this: the stereo or dual mono signal goes into the split, it is duplicated to path A and B and on each of those you can control the balance between left and right, those balance control also have a pan law but different from the merge mixer block pans ! in this case it's unity at center and +3dB at sides ! (I think the reason for this is to avoid an attenuation to the splitted signals at default settings) so if for example you use 2 amps in the paths do not use these parameters or the two amps will receive a different level than if the balance is at center. --- • to finish I'll add two other Helix Routing measurements I found during my tests: - the pan block is actually a balance control with a pan law equal to that applied in the split Y block: at center it's at unity gain, going to the left attenuates the right up to minus infinite and adds +3dB to the left (and viceversa) - unlike the POD HD500 the fx sends / returns on the Helix are all at unity gain levels (+/-0.3dB), thanks Line 6 ! --- thanks for reading, I hope to have been helpful bye Lorenzo

please can you anyone confirm what bvaladez74 said, that the footswitch midi capability is only working when you are in FS5-8/pedalboard mode? To be clear does it mean that even the four UPPER footswitches don't send any midi data while in ABCD/preset mode? that would be weird (I'm buying an external midi controllable multifx to control it in ABCD mode from the pod with MIDI PC and MIDI CC so this info canmake me change idea!!) the manual says <<footswitches FS5 - FS8 will only transmit your configured MIDI assignments when their Setup option is set to the FS5 - FS8 “Pedalboard Modeâ€>> and this seems obvious since FS5-8 are in ABCD mode, but what about FS1-4? by the way this is a FULLY configurable foot controller for a smaller price: http://usa.yamaha.com/products/music-production/midi-controllers/mfc10/ maybe Helix will include something good from yamaha ;) thanks for any info Lorenzo

this could also be useful: http://line6.com/support/topic/12972-cab-dep-parameter-measurements/

hi this is a known bug it has to do with the edit software communication with the pod the workaround is: when this happens, after you send the correct patch to the pod you need to also save the patch on the pod itself (by pushing the save button 2 times)

Hi, I don't own the ns-2 but I'd say this is how it should be done: gtr > ns2 in > ns2 send > pod in > "pre fx" > pod send > amp in > amp send > ns2 return > ns2 out > pod return > "post fx" > pod out > amp return wow... that's a 6-cable method ;) a LOT of cables! so I'd compare this to just putting a pod's internal noise gate after the fx loop return and see if it's worth it

I meant exactly what edstar1960 described over here... I also wonder how they managed to "optimize" the DSP usage to make the Global EQ compatible even with the most DSP-expensive patches... and I'd add only that a parametric eq fx block should be with 2 bands only to be DSP-friendly not holding my breath neither anyway ;)

this is what you're looking for http://www.sonuus.com/products_g2m.html guitar to midi notes converter only one note at a time though, no chords

great job pfsmith0 !! now, why can't we have an fx block identical to this eq?!? that would be savable per patch and movable along the signal chain, I mean even if with only 2 bands at a time but with Hz and dB's instead of % and without analog clipping simulation come on Line 6, put it in v.2.63 !!

hey there hurghanico! and to pianoguyy: I did the blank setlist too, it's so good to start from scratch! :-)

and the Variax setlist seems to be more useful than other setlists for non-owners of the variax too: http://line6.com/support/topic/13167-variax-setlist-patches-for-standard-guitars/

good to know, that was my intent!

thanks, link edited

and to Gazza if you only need a simple setup you don't need to know all aspects of the routing (it doesn't hurt of course, but you don't NEED to), just: - load an empty "new tone" patch - load an amp (leaving the amp block where it is) - IGNORE the A/B paths and the mixer - load the pre-effects before the amp - load the post-effects after the mixer yes, it's THAT easy :)

hi darwan23 I'm the author of the first schematics in this thread, you did great with graphics, good job! I'm sorry to be so late but I'm not following this forum much I just have a pair of doubts/questions for you on the fx blocks you drew 1- which effects do you have in mind as "true stereo" as opposed to "Stereo THRU/Stereo Fx block"? I think this distinction does not exist ** 2- the "-6dB" involved in the mono summing into the effects is missing in your schematics, but I think it's very important to understand how the pod routing/gain-staging works ** what you call "Stereo THRU/Stereo Fx block" IS actually true stereo, but a stereo effect that does not provide a mix knob such as an equalizer for example is true stereo too; from your "true stereo" schematic it seems that these effects treat the left and right signals separately and generate two DIFFERENT STEREO signals and then mix them together: no effect that I'm aware does such a thing in the pod (only some evoved convolution reverb plugins actually do something like that). --- Another two things I feel I need to clarify on your schematics for people that are trying to learn from this thread: 3- the two big schematics (with and without "pre split" FX) are exactly the same, in fact I think darwan23 could get rid of the first one the difference resides in which kind of effect someone chooses to put before the split, if it's stereo it will leave A and B paths separated if it's mono or "mono fx / stereo thru" it will do what their schematics show 4- the continuous vs dotted lines to distinguish between mono and stereo signals could be confusing, in the sense that the dotted lines labelled L and R could also be representing two identical signals running in parallel which IS mono... it all depends on which effect you put where also the two inputs could carry two sides of a stereo signal so the continuous lines could refer to a stereo and not mono signal what I'm triying to say is that in darwan23's schematics there is no difference between what is drawn in continuous or in dotted fashion (it could be all continuous and work the same) as always, I'm just hoping to help bye Lorenzo

yes it's the one in the first post of the thread

hi optimus_7 1) the problem of the level drop at the send is well known on this forum, I did many tests on my pod, please read here: http://line6.com/support/topic/2040-pod-hd-500-the-fx-loop-attenuates-the-signal-at-the-send-jack/ 2) sorry your assumptions are wrong, there is NO +4dBu nominal level input or output on the pod all the "line" are roughly at -10dBV and all the "amp" and "stomp" are at instrument level, while the XLR's are at a (actually hot) microphone level +4 is for studio-grade signal processors 3) also don't be fooled by labels, +4dBu, -10dBV, stomp, line, amp, instrument ... are the NOMINAL level labeling so a +4 OUTput sends a higher level than a -10 BUT a +4 INput (like the return jack) "waits for" a higher level so it's in fact attenuating the input signal (or, more rarely, the corresponding -10 INput is amplifying it) SO when you select "stomp" on the fx loop it's sending a lower level and boosting at the return when you select "line" it's boosting the send and attenuating the return this is the normal behaviour of any fx loop (even that of your amp) 4) "if I change the Unbalanced Out on the POD HD to LINE, my volume drops significantly and the gain doubles..." that's really weird, could it be power amp compression/distortion? the output switch should attenuate by roughly 12dB on the amp position which is intended to connect to an amp guitar input the line position should be right for an amp fx return the most "correct" starting point settings would be: pod fx loop to stomp, amp fx loop to -10, and pod output to line but experimentation and your ears are the guide

this is a known bug after you "send" a patch from the software editor to the hd500, you should use the "save" button on the hd500 before using the unit's footswitches to change patch otherwise many parameters will not be really saved the mixer seems to suffer from this bug more than other blocks see here: http://line6.com/support/topic/2457-hd-500-edit-mixer-volume-droppingnot-saving-to-unit/ and please vote here to ask line6 to solve the problem: http://line6.ideascale.com/a/dtd/HD500-bug-mixer-faders-not-saved-with-send/529219-23508

you only hear a tiny difference in level in the tails of your notes because both the tube comp and the distortion of the amp do compress the sound a lot

with my tests posted above I demonstrated that attenuating the input signal with a volume pedal by 6dB or with the "single input" setting gives exactly the same result, ... ...now a QUESTION arises: is it possible to compensate the difference between single input and dual input by just using the drive pot on the amplifiers? to answer, I did some other tests starting from a guitar/guitar patch (A) duplicating it and changing to guitar/variax (B ) and then setting the right amount of drive by ear and then comparing the two patches in two ways: - with a guitar signal by ear - sending a sine wave (0dBu @ 1kHz) and looking at the FFT's (I chose 7 amps, an amp+overdrive and 1 amp+boost) http://en.wikipedia.org/wiki/Fast_Fourier_transform playing guitar and sending a looped riff, I can hear subtle differences on a couple of amps where I can't find the right value for the drive (but the difference is not clearly better/worst it's just a bit different) looking at the FFT's those same amps have one or two different harmonics levels between A and B: soldano jcm800 + screamer plexi + boost comp (the plexi alone doesn't have this problem so the boost comp is clearly the culprit) another pair have micro differences in a couple of harmonics (and I can't hear the difference): twin vox ac30 the rest looks and sounds the same jtm45 plexi park 75 mesa bear in mind that the differences are tiny (except for the soldano, the "worst": 10db on the 3rd harmonic and 3dB on the 2nd) and that I wouldn't choose one or the other (A/B) based on these tests (you have to play with the sound in context to chose what you like more), but I can confirm that there are some little differences. I hope this work of mine at least can give you a method to build two identical patches changing only the input setting and the drive value to compare them and, in each case, choose which sounds best to you here you are the FFT's (where red is A and yellow is B and the white horizontal lines are every 10dB) and the setlist to try for yourself: https://dl.dropboxusercontent.com/u/8875989/Pod_HD_forums/amp_drive_vs_input_settings_by_perapera.zip SUMMARIZING • choosing a single input is ONLY attenuating the input signal level by 6dB (no phase or other issues) (I also re-tested the patches I uploaded with my original post with the sine wave/FFT method and all the A/B couples are identical: this confirms one more time that the single input is just an attenuation of 6dB at the input) • some amplifiers/fx models can have a slightly different sound thanks to this attenuated signal independently from their drive pot position (maybe because there is some pre-drive-pot circuit ?!? thanks to gckelloch for the idea) so bear in mind that if someone wants the attenuated signal to be sent to his amp and wants to put it on A or B path, he needs another way to attenuate the signal (since he doesn't have the possibility to attenuate with the input settings choice): he can switch the pad in, he can add a fixed volume pedal @71% before the amp or he can activate only one input and then add a noise gate (100/0) which acts as a splitter in the PRE path and then put the amps in A and/or B path (this is how meambobbo does it); (using a studio eq as an attenuator is NOT a good idea since it has its sound, even at unity and it also sucks CPU power) • overdrive and distortion fx blocks send a higher level to the amp than the direct guitar, so if you don't like the sound of a specific distortion block into a specific amp, it could be a good idea to lower the distotion block output volume instead of lowering the amp's drive CONCLUSION So, if the routing you use allows you to do it, it's worth comparing the single input vs the dual input (the comparison must be made, as I did, with two identical patches changing only the input setting and the drive value); if your routing doesn't allow you to try different input settings (e.g. you use two instruments on two separate paths) you can also try a fixed volume pedal at 71% before your amp/distortion pedal bye and happy new year! Lore

actually the most accurate measure I did gave me -5.4dB ;-) it can also be that not each resistor in each pod unit is the same...

sorry guys I had to re-upload the zip again (!) I found an inconsistency between the setlist saved on PC vs my setlist on the pod thanks radatats! now another good independent test confirms my routing schematics' truthfulness by the way I updated the drawings to make them clearer http://line6.com/support/topic/2033-pod-hd-500-500x-new-routing-schematics/

I updated my routing schematics the mods do not concern the content of the routing It's just a clearer way to explain the same signal routing many thanks to Milan, Line 6 fan and Line 6 manuals' translator into Czech language for inspiring me in doing that cheers Lorenzo

Thanks to you, Milan, I started modifying my schematics and ended up with a version I like A LOT! you can redraw your version and publish it, but I think that here I'll stick with this handmade version at least for a while bye and happy new year! Lorenzo

you're absolutely right and the reason is that with only Input-1 active you are NOT using the split which sends the signal on path B so, as you said, it is always possible to clip the pod internally or to clip the D/A by the routing choices and levels you set in each amp or fx one of these choices is the input setting, but this has effect only on the (digital) input of your fx chain in a real setup, if you are saturating the amp speaker, do you lower the volume pot on your guitar or the master volume on the amp?