delays and Reverb Tails

[lucasvnb]

Hello! I am a new line 6 user. I bought a POD GO a few days ago and I really like it. Although I have a little problem. When I switch between a preset with some delay and reverb to another preset with a rhythm distortion, I can't get the delays and reverb tails to keep playing in the background, I change between the presets and these effects just cut off right away. Can someone help me with this?
PS: Yes, I turned on the "tail ON" button on delays and reverb.

[silverhead]

This is normal behaviour. Delay and other trails do not continue when you switch presets; they cut out immediately as you are observing and there’s nothing to be done about that for technical reasons (a single DSP a chip in the device). The Trails On/Off setting only controls the behaviour within the same preset when you switch those FX On/Off.

[voxman55]

4 hours ago, silverhead said:

This is normal behaviour. Delay and other trails do not continue when you switch presets; they cut out immediately as you are observing and there’s nothing to be done about that for technical reasons (a single DSP a chip in the device). The Trails On/Off setting only controls the behaviour within the same preset when you switch those FX On/Off.

I'm not sure it's anything to do with single or dual chip. As far as I'm aware, dual chip Helix units are the same ie trails only carry over within the same patch.

[silverhead]

As of firmware 3.0 Helix does support true spillover between presets - but only if each preset uses only one signal Path. That’s because it dedicates one of its 2 DSP chips (paths) to each preset. So, yes, preset spillover is directly tied to number of DSP chips.

 

The POD Go device likely will, in the next firmware update, get some of the new goodies in Helix firmware v3.0. Preset spillover will not be among them because of the single chip limitation.

[voxman55]

Ah, so it's only a brand new thing then with Helix following v3.0. Personally, I don't think it's important because in a live mix the audience will never notice it and most changes mid song can likely be done via snaps and stomps in the same patch that will give trails.

 

 

[silverhead]

Personally I agree with you. But Line 6 implemented this so it appears there were enough users requesting it on Ideascale to warrant it. Which means lots of users are willing to sacrifice 50% of the DSP in their presets to be able to have true preset spillover. Go figure. Fortunately those of us who don’t want to use this don’t have to! Nothing wrong with an advantage for some that doesn’t disadvantage others.

[malhavok]

Spillover is a neat feature that only the original read bean POD and the POD XT had and no other Line 6 unit had until Helix got the 3.00.0 update. It's less to do with requiring two DSP chips, per se, and more to do with requiring two things:

 

1. Both presets (the one you're coming from and the one you're going to) must "fit" simultaneously in your overall DSP "horsepower" available. In simple terms, the only way to guarantee it is to limit any preset to use no more than 50% of available power. On Helix, this is easily achieved by limiting each preset to a single DSP chip.
2. Then, you must also be able to process all available channels of both presets simultaneously. This is the stickier point. A POD Go preset has two channels (left and right) so to support spillover, you'd need to not only limit 50% of the processor per preset but you also now need to be able to process four channels (L+R of both presets) simultaneously. On Helix, a preset on a single DSP has four discreet audio paths (L+R for both A and B paths) so spillover is again easily solved by "per DSP" processing of each preset which subverts the need to process eight channels of audio on the chip.

It is not known to me if POD Go's DSP could process four channels of audio simultaneously. Even if we assume it could process two L/R pairs of audio, we'd still be limited to 50% of power. That means you'd sometimes not even even be able to fit a delay or reverb as the amp+cab together can often take the full 50% of power.

 

How did they achieve it on the old PODs then? Well, those did not have dynamic DSP. The original red bean did not even have delay "models" and just had what you might think of as a global digital delay that could be on or off on any preset. Its position was not assignable. It was in a fixed position in the signal chain just before the reverb which was also across all presets and fixed last in the chain. On the XT, my recollection is also that spillover really only worked correctly with delay in the "post" position and that when some other "global" type of feature was introduced introduced (in an update) you could either have that feature or delay spillover, but not both. No Line 6 unit after that ever supported spillover until Helix 3.00.0 release.

 

The trade-offs to support spillover are large. You can trivially support spillover if you sacrifice either a great amount of power or a great amount of flexibility. I think it's great we have the option to choose behavior on Helix but I'm skeptical we'd ever see it on POD Go. Though, I can think of a way it could be done if it required the delay to always be very last in the chain and always be a fixed delay model... My personal vote would be for other features instead of spending time on that.

[silverhead]

Yes, I guess it’s a 50% DSP thing rather than a single/dual chip thing. Thanks for the explanation.