Why Is FX Loop Block Red?

[Wondo100]

IN 4CM the FX Loop Block is clipping red. Big Volume Knob is at 12:30 All outputs seem fine. Instrument level. 

 

 

[rd2rk]

It's clipping. Check the levels on everything in the signal chain before the FX Loop. If your pickups are super hot you may need to engage the Input Block Pad.

[Wondo100]

Thank you. On the particular snapshot where it is clipping, all of the effects before the FX loop are off. It is a clean channel on my amp. My overdriven channels are not clipping. 

[rd2rk]

What amp are you using? Is it a Serial or Parallel FX Loop? Does it have it's own level control? Is the amp's Master Volume before or after the FX Loop?

If it's sending back a LINE level signal, and the loop is set to Instrument, you may need to use separate Send and Return Blocks set appropriately..

Try turning down the Helix FX Loop Send Level, then the Return level. That might identify where the clipping is coming from.

[Wondo100]

Quote

What amp are you using? Is it a Serial or Parallel FX Loop? Does it have it's own level control? Is the amp's Master Volume before or after the FX Loop?

If it's sending back a LINE level signal, and the loop is set to Instrument, you may need to use separate Send and Return Blocks set appropriately..

Try turning down the Helix FX Loop Send Level, then the Return level. That might identify where the clipping is coming from.

rd2rk, 

Thanks for this. I am using Two H&K Grandmeisters one is the 36 and one is the 40. The one that is clipping is the 36 on a clean channel. Both amps use a serial FX Loop. I believe that the Master volume is after the FX Loop. I do not think it is sending back a line level. I believe it is at instrument level. I have tried messing with the send, return and 1/4 levels and that can make the clipping go away but then the amps sound like poop because when I switch off the FX loops on the amp they go back to their normal level which sounds great. I am including a picture of my signal path and a picture of the manual which outlines levels for FX loop of the amp. If I can get this issue under control, it will be awesome because my set up is pretty sweet. Thanks. 

[rd2rk]

I can't tell much from a picture. Attach the actual preset and I'll look at the settings.

One thing that stands out, each path has both an FX Loop and a separate Return. Why is that?

 

[Wondo100]

Here is the preset (attached below). I took out the two return blocks that were there. I had them there because I was experimenting if having a separate send and return would help. I did not notice much, but not sure if I set it up right. Wish I could get this sorted out. I don't notice any clipping in the sound, but I am sure it is not supposed to be like this. 

 

You will notice that the 1/4" outs are both boosted by +3db. The 1/4 outs go to the amps FX Returns. This was the setting that matched the amp volume between FX loop on or off. I tried putting these back to 0 and the clipping still occurs. YMMV

 

Also included a picture of how I have the 7CM set up. 

 

Thanks!

Hemispheres.hlx

[rd2rk]

Here's a modded version.

I set all of the Ins/Outs/Loops to Instrument level.

Input PAD (Global) is ON.

My guitar has a Seymour Duncan JB in the bridge, which is pretty hot for a passive Alnico pickup (16.6k).

Using the meters on my 18i20, I set all of the Loop and Output levels to just below "YELLOW (vs RED)" when HARD picking. IOW, always in the GREEN.

I tied the Output Block Levels to the FX Loop Bypass switches so that the levels are the same whether ON or OFF, for BOTH Path 1 and Path 2.

That means that both amps should be getting the same level, regardless of whether the FX Loops are ON or OFF.

Nothing is clipping, and there should be sufficient headroom in the loops.

 

I only did this on the default Snapshot. None of my settings are tied to Snapshots. Save a copy BEFORE you start modding it.

 

Hemispheres Mod1.hlx

[Wondo100]

Thanks! This looks good. I am going to try this now. I noticed the second Signal path with the second FX Loop is -10db. I don't think I had it like that before. I am not sure what you mean when you said you tied the output block levels to the fx loop bypass switches.

[rd2rk]

27 minutes ago, Wondo100 said:

Thanks! This looks good. I am going to try this now. I noticed the second Signal path with the second FX Loop is -10db. I don't think I had it like that before. I am not sure what you mean when you said you tied the output block levels to the fx loop bypass switches.

 

You had the problem of different levels from the amps with the Loops On or OFF. Now when you turn the Loops On or Off the Output Block levels change to accomodate.

[Wondo100]

Ok. Still getting the same problem. The first two snapshots with my overdrive sounds on the amp are not a problem. It is the clean channel that is causing it. Even when I switch the loops around it still does it in the other loop, so it is not the amp. I am getting to the point of giving up. I have been working on this for weeks now. I cannot get it to stop clipping

 

 

[rd2rk]

I don't know what to tell you. The FX Loop levels are NOT clipping. The meters tell the tale. There's PLENTY of headroom.

Since the levels I set are NOT connected to Snapshots, and the first two snapshots are fine, what is it about the other snapshots that is causing the clean (Path 2?) to clip?

 

I just had another look. You've got the Return on loop 2 set to add 4db on SS2,3 and 4. Try deleting that. Here, I did it on the attached.

Hemispheres Mod2.hlx

[Wondo100]

Yup. No matter what I do, it is there. Only if I turn down the channel volume on the amp does it work and we are talking about half way down from where it is now. Why would I want to rob my tone this way? I can bring send, return 1/4" levels down on the helix as well as big volume knob and it is still there. I can even put a volume gain right after the FX loop, on the signal path. Turn it on so that no signal is going to my amp, dead quiet and the FX Loop Block still clips red on the Helix.

[Wondo100]

9 minutes ago, rd2rk said:

I don't know what to tell you. The FX Loop levels are NOT clipping. The meters tell the tale. There's PLENTY of headroom.

Since the levels I set are NOT connected to Snapshots, and the first two snapshots are fine, what is it about the other snapshots that is causing the clean (Path 2?) to clip?

 

I just had another look. You've got the Return on loop 2 set to add 4db on SS2,3 and 4. Try deleting that. Here, I did it on the attached.

Hemispheres Mod2.hlx 28.12 kB · 0 downloads

It is snapshot 3, that is clipping. The Clean Snapshot. The first two are fine. Always have been. 

[Wondo100]

Thank you again for doing this! I have moved these levels up and down at nauseam. It still clips no matter what I do on Snapshot 3 the clean channel. 

[rd2rk]

If only ONE snapshot clips, then it HAS to be a setting in THAT snapshot.

Try lowering the Send Level on THAT Snapshot. Be sure you're saving it, and be aware that whenever you change assignment levels you need to switch out and back for it to take effect.

 

This is the sort of problem that L6 should use as a case study on why you should use two Power Cabs and L6 Link!

 

There really isn't anything more I can do, Even with your original preset, I can't get anything to clip on ANY snapshot!

Not to say that you're not hearing what you're hearing. You are using two amps, different ones at that, whereas I'm playing a different guitar and looking at meters on a mixer. It could be just a hair of a difference in a level someplace that's causing your problem, and I just can't see it on my equipment.

 

Anyhow, Good Luck!

[Wondo100]

Thanks rd2rk. I really do appreciate all of your help. You have been great. Both amps are Grandmeisters. Even though one is a 36 and one is a 40. They are pretty much the same amp. I had Powercabs on order and then cancelled because I really want to use my amps, but I ordered them to avoid exactly what I am experiencing. Do you think I should go ahead and get the power cabs? If I play out I would never run both of these GMs anyway that would drive me and the soundman crazy. I would just run 4CM and use either a HX Effects or a MS 3 (if I want it simple) I am just trying to use the Stereo set up  in the studio to get multiple amp tones and use my Piezo. 

 

As far as clipping. The sound is just fine as far as I can tell, it is just that the block keeps turning red on Path A on the clean tones on snapshot 3. 

 

Thanks,

Bill

[rd2rk]

I guess my biggest problem troubleshooting this was that I never was able to get any of the FX or Output blocks to turn red. Maybe the problem is not the Send level, but the Return? That's what I can't duplicate with my setup, your amp's FX Send level. When I suggested using separate Send and Return Blocks, I should have specified to set the SEND to Instrument and RETURN to Line. You said you tried that, is that what you did?

 

As for the PC+ vs the GM, I've found it's usually best to simplify. Eliminating the FX loop variables saves a lot of hassle.

OTOH, if you REALLY like the GMs, and can afford it, get the Powercabs to try BEFORE you sell the GMs.

 

 

[Wondo100]

I never did that. Would I just put the send right before the return kind of like I have now with just the loop? I do not think I tried that. As far as PC, I am going to try them. If I like them, I would not sell the GMs. Probably just use one and keep the other as back up, unless I can sell one at some point. What do you think of the PC?

[rd2rk]

5 minutes ago, Wondo100 said:

I never did that. Would I just put the send right before the return kind of like I have now with just the loop? I do not think I tried that. As far as PC, I am going to try them. If I like them, I would not sell the GMs. Probably just use one and keep the other as back up, unless I can sell one at some point. What do you think of the PC?

 

Yes. just place the send 1 (Path 1) and 2 (Path 2) set to Instrument next to Return 3 (Path 1) and 4 (Path 2) set to Line and wire accordingly.

 

As for the PC, I wish I could afford two. When I used a 15/112 tube combo as a second, it sounded different, but I can't say all that much better. I'm getting by with a FRFR112 as second, which also sounds different, but not better.

[Wondo100]

Can I have path A send 1 and return 1 and Path B send 2 and return 2 to keep the same 7CM wiring as the picture in my above post?

[rd2rk]

4 minutes ago, Wondo100 said:

Can I have path A send 1 and return 1 and Path B send 2 and return 2 to keep the same 7CM wiring as the picture in my above post?

 

No, because the Global settings work in pairs - Send1/Return one both EITHER Inst OR Line; etc.

You need to be able to split them - Path 1 Send 1 INST/Path 1 Return 3 LINE.

I use those for the sake of remembering - Left is ODD (Path 1), Right is Even.(Path 2).

[Wondo100]

OK I will give this a try if it works, I essentially use all of my effects loops up for this arrangement

 

[Wondo100]

That does not work. Robs tone even more. I have padded the guitar input and then adjusted the send levels which is kind of silly because the send is actually going into the front of the amp, so I am padding a pad as it were. That seems to allow the FX Loop clipping to not happen as often, but it still does when strumming hard, but maybe that is normal. This configuration does not rob tone. I also ended up turning the big volume knob on the Helix all the way up. 

[qwerty42]

I need to do some more testing, but it looks like there might be a bug with the sends/returns and that clipping indicator...?

 

If you set up a preset with a separate 'send' and 'return' block, and then use a patch cable from send 1 directly into return 1, and run a test signal through it, the return block starts clipping about 14dB sooner than the send block. This might be a faulty indication, with it not actually clipping, or it could be a result of the return's A/D having less dynamic range than the 32-bit floating point math that happens once it's in the digital domain. That doesn't seem right though, because the level meter for the send should be a level based on the send's A/D headroom.

@Wondo100 -- are you using firmware 2.92? Which Helix device are you using (floor, HX effects)?

[Wondo100]

Yes. I am using 2.92. When I spoke with Line 6, they thought that the effects loop issue was a bug and would be fixed in the next update. That was about a week before 2.92. That did not fix anything, and it was not listed in the release notes. I do not notice any sound that would indicate clipping. What I notice is that the fx loop block turns read when I am playing. I am using Helix floor and it is pretty much a brand new unit. All new cables. 

[qwerty42]

This likely won't fix the problem, but it will let us pinpoint it. I've attached two presets -- please try the following:

1. In your Global Settings, set "Send/Return 1" to Instrument.
2. Also in Global Settings, set "Send/Return 3" to Line.
3. Also in Global Settings, turn off the "Guitar In" pad (it really shouldn't be necessary).
4. Drop both of the presets I've attached onto your Helix.
5. Put all your amp knobs where you had them before, when they were working with the first two snapshots but clipping on the third.

Next, do this:

1. Set up your amp's send and return cabling into Send 1 and Return 1 on your Helix.
2. Load "Hemis_Snd1_Ret1". Make sure it's on the 3rd snapshot. Try playing and watch the Send and Return blocks on Path 1A. Is one of them flashing red? Which one? If it's the Return block, try lowering the "Return" slider within that block. Does that make it stop flashing red?

Next, try this:

1. Set up your amp's send and return so they are going into Send 1 and Return 3 on your Helix.
2. Load "Hemis_Snd1_Ret3". Do the same as above. Are either the Send or Return blocks still flashing red? If not, does it sound good? If you need more output from the return, you can turn its level up using the "Return" slider in the "Return" block.

Let me know what you find from the steps above and we'll go from there. I still think this may be a bug, but I think there's a solution here regardless.

Hemis_Snd1_Ret3.hlxHemis_Snd1_Ret1.hlx

[Wondo100]

Ok. I will give this a try. When you say amps send and return cabling, should I keep the cabling the way I have it in the picture I posted below? Or should I do something different?

 

On another note, I thought that to bypass all of this 7CM complication that I would just get two Power Cab 112s and run through the L6 Link cable, but that would mean I am relying on the amp models in Helix to do this and when I try to set things up to do this, I run out of DSP space. In other words it would seem that in order for me to use snapshots and be able to have two amps running one in clean, the other overdriven and then in the next snapshot have both overdriven with the Piezo mixed in and then move to an all clean sound on both amps with Piezo mixed in, the only way to do this is with my external amps because they are fully programmable and each snapshot can send a CC to the amps to bring up the desired amp sound. Doing this within Helix with models only and no FX loops, I cannot do this. 

[qwerty42]

Yes, keep it set up like in the picture, with the exception that the 'send' from the amp needs to go into either Return 1 or Return 3 on Helix, as per my instructions above. Please make sure you follow every step I listed so we can draw a valid conclusion from it.

I only changed Path 1 on snapshot 3, since you said that was the one which was clipping. I split your send and return into separate blocks, so we can see for sure which side is clipping. (You have the option to either use an 'FX Loop' block with Helix which combines Send and Return, or you can use a separate Send and separate Return block. The way you had it setup before had an FX Loop block so we have no way of knowing if it was clipping on the send side or the return side). I also built the 2 presets and had you configure the global settings so that in one case, both send and return are instrument level, and in the second case, the send is instrument while the return is line. If you really are clipping a line level return, something really weird is happening and merits more investigation, because the Helix should easily be able to handle what you're doing with it. Anyway, don't overthink it at this point -- if you follow the steps exactly as I wrote them, we can go from there once we see what happens.

Regarding your Powercab idea, are you sure you'd run out of DSP? You wouldn't be able to use multiple amp blocks on a single split path, but you could definitely have 3 amp blocks total and use snapshots to adjust their gain levels and output volumes. Since the Powercabs have built in cab modeling, you could skip the cabinet models in Helix itself and save yourself even more DSP. If you wanted to use the Powercabs as FRFR speakers instead, you could even merge your amps back to a single cab (or stereo cab) block on each path to save DSP. It takes some thought, but there are many, many ways to skin the proverbial cat with Helix. I see you're using some very DSP-intensive delays -- you might be able to consolidate them to a single stereo delay block and feed multiple paths into them. If you had DSP to spare on Path 1, we could also use its B path to offload a couple of your effects and send them down to path 2. It's all about balancing the DSP utilization of each path so you can cram the max possible into it.

[Wondo100]

Thanks. I will try this in a little bit when I can turn things up to get the results. I will let you know soon, Thanks for your help.

 

[Wondo100]

OK. So, first method under preset Hemiis_Snd1_Ret1 gets same results with clipping. 

 

Hemis_Snd1_Ret3 does not get the clipping, although the sound is a bit robbed in fullness of tone between FX loop on my amp and off. I think I have some headroom though to remedy this. 

 

I believe that this is what rd2rk was having me try, but maybe I missed something in that because it was not working when I did that, I may have got some cabling mixed up. 

 

So, now what does this tell us? Am I going to have to set it up like this? If so, I have to use all of my FX loops to run 7CM??

[qwerty42]

Which of the blocks is clipping? It's the one labeled 'Return,' yes? (In the patches I gave you there are separate send and return blocks on Path 1).

If so, it tells us this:

• Assuming the clipping indicator is correct (which it might not be), then using a line-level setting for the Return eliminates the clipping. That means worst-case scenario, we can still use Helix with your amps without clipping. Yes, routing this way requires FX Loops 1, 2, 3, & 4 to use both your amps. This is indeed what rd2rk was trying to have you do, and from the results I suspected it wasn't actually achieved.
• Any tone-robbing issues you're hearing from the line-level return should be fixable by simply increasing the 'Return' slider of the 'Return' block, or if that causes clipping, then boost the level on the 1/4" output at the very end of Path 1 instead.
  • There isn't anything about using a line-level return that should be robbing tone, except that the level going back out to your amp at the very end of your chain will be slightly less, so add gain after the Return to compensate
  • If you still hear tonal differences after adding some gain after the return block, then it's possible the 'tone loss' you're hearing was actually the clipping giving it extra bite/brightness
• Your options in the end are:
  • Run Helix like this, splitting the Sends are Returns so the sends are instrument-level and returns are line-level.
  • Trust your ears, and use it as it was before with the return 'clipping' until we can get Line 6 to verify whether or not that indicator is correct.

For what it's worth, if the Return really is clipping and the indicator's working properly, it means your amp is the issue, because for some reason it's sending back a signal which is hotter than 'instrument level.'
 

I will submit a ticket to Line 6 with my findings on the Return blocks lighting up well before the Send does if they are patched straight into each other, and see what they say.

[Wondo100]

Thanks qwerty42. I really appreciate it.

 

Also appreciate both you and  rd2rk taking the time to help. I feel like this is the place to get some answers!!

 

Yes it was the Return that was going in to the red. Interestingly, it does not do it on the other amp in the usual configuration. Therefore, I could use it like this:

 

Path 1: Guitar In> Dynamics, Dist., Mod, etc. >FX Send 1, FX Return 3> Volume Block, time-based effects, etc.> 1/4" out Panned all the way to the Left

Path 2. Guitar In> Dynamics, Dist., Mod, etc. >FX Loop2> Volume Block, time-based effects, etc.> 1/4" out Panned all the way to the Right

 

This still leaves me with FX Loop 4 to use if I need to. So, if it is the amp (GM 36) I am not sure why this would be doing this. It works fine, no sounds indicating bad tubes, although it has been a few years since I changed out the tubes. My other amp (GM 40) is less than a year old and I just put all new JJ tubes in there yesterday to replace the weak Chinese tubes.

In the GM 36, I have Tung Sol preamp tubes in all three slots and then TAD power amp tubes. I am not sure which of the tubes if any are related to the FX Loop. 

 

Although, I will really have to experiment with Path 2 to make sure it is not doing this either. 

 

I found a schematic from a H&K forum about 4CM and they are saying to do it with separate Send/Return

[Wondo100]

Oh, and thanks for sending a ticket. When I switch amps out, it still does it in the old configuration. I suspect it is a bug in the system. Hopefully, it is not my Helix unit. I got at the end of 2019 and had my first real chance to start working with this set up in March. So, it is still a new unit (still has the plastic on the main display and scribble strips in case I had to turn around and sell it).

 

I am expecting two PC+ to arrive in a few days to try them out with a return option. Not sure if this will make for a good situation, or create more headaches. 

 

If I can replicate what I am looking for with Power Cabs, then I might go that route. 

 

I chose Rush Hemispheres as the patch to build, because if I could get that to work, then anything is possible. Alex was not that sophisticated on stage (nor was there the same technology) in 1978 as was available to him in the later years. However, I am trying to duplicate the sound on the Hemispheres album Cygnus X-1. He uses an overdriven sound, then a clean sound on top of the overdriven sound with an overdubbed acoustic, then just pure clean with acoustic. With my Les Paul Axcess that has hum buckers and Piezo with separate output for Piezo, I need to be able to blend these all together. With 7CM, I have Path 1 in Helix go to the amp that is overdriven, Path 2 goes to amp that is clean and the third path is the Piezo which goes out to a Fishman Loudbox. That gets the tone since with each snapshot, I can change the settings on the amp if needed like I do with the clean amp to give it more drive in one of the parts. I do not know if I can do something like this with the PC+. Might need some help. 

Thanks!