Gapless preset switching

I know it is written explicitly that the “inevitable” gap between preset changes will occur, so I can’t claim I wasn’t warned. Nevertheless, I really wonder why this is de facto inevitable in the most powerful pedal modelller on the planet in year 2021. I have many other devices, which have no perceived gaps (or at least much less) or/and which support spill-over of delay/reverb between even complex preset changes. Please implement at least spill-over, since I can’t cram all my sounds into one preset and solve the issue using scenes (tried yesterday, but QC runs out of resources…). Are there other workarounds apart from adding a further physical delay/reverb device after the QC?..

As I understand it, the delay comes when you allow complex signal chains because it takes time for the processor to set up the new signal chain in memory, interrupting audio flow. The way some devices (GSP-1101 and more recently Helix) accomplish gapless preset changes is to reserve half the processing power and have the new chain set up before switching the audio stream to the new path. Question is, who wants to give up half their device’s CPU?

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Sure, it takes resources, but if other highend (and even low-end) devices can do it, why can’t the QC?

After all they claim that “Quad Cortex is the most powerful floor modeler on the planet. With 2GHz of dedicated DSP from its Quad-Core SHARC® architecture, this ludicrous amount of processing capacity provides limitless sound design possibilities.” and “Want to run four amplifier models, stereo reverbs, and a plethora of other effects simultaneously? Quad Cortex won’t even break a sweat.”…

Accordingly, it is hard to buy the argument that the device should not have resources to at least do spill-over between presets. That’s simply self-contradictive.

By the way, you are right; it seems there are bigger gaps between more complex presets than between simpler ones.


I think the half power reservation approach deserves to be an option. While this may not be for everyone, I think there are people out there who will be satisfied with two stereo paths for all their tasks, and would prefer to have a gapless preset changes.


I have no issue with it being an option the way it is on Helix. OTOH, I think a lot of folks would slow their roll on gapless switching if they could only use two paths in a preset.


Hey, you explicitly asked for presets but there is a workaround for switching sounds between scenes.

You cannot simply disengage/ bypass inputs or outputs but you can disengage/ bypass split signal paths.
You also cannot bypass your effect blocks (because you will have parallel DI sounds with your desired one.

Example with 3 tones:

  1. Use signal splitting (either as first block or after your gate f.e.)
  2. Turn it to A/B on row 1 & 2
  3. For scene #1 (to avoid confusion) leave volume A intact and turn signal B OFF
  4. On your “lower”/ second signal split (row 3 & 4) turn OFF that A + B
  5. For scene #2 turn OFF path A (on row 1 & 2) and have path B engaged. Second split (row 3 & 4) still OFF.
    and so on…

Hope this helps. It’s a tedious work around but it is cleaner than turning down the volume on your amps (-60db is not nothing to me). But you can experiment with that, too, of course.

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I’d be willing to give up half the power for spill-over too! Like on the Helix, could be an option and it would be up to the user to take that path or not.

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I play so times in concerts, and short events, when we know all the musics that we will play. Its so cool, in QC i can create a presets with 8 sounds that i want to use for each music, perfect. But we get too some bigger events, when we play all day, 2…3 days. In this last case, we don’t know what were are going to play, untill the music starts. In Brazil we have a lot of rhythms and styles, in addition, we play a lot of american rhythms and styles too.
What am i
traying to say? I need flexibility and a lot of timbres, so fast, to play freely, impromptu. 8 timbres easy is to little in my case. If I could alter the preset, during a song, like i do in my big rig (no sound break, noise and keeping the tail of delays and reverbs), will be wonderful… please help us!!!
I have seen people using delay, reverb and modulation pedals apart from the QC, many times to tryin minimize this problem, its not cool, QC can be self-supporting. In this point, we just need to have at our feet the possibility of changing presets, to increase the possibilities, without breaking the sound, or losing the tails of reverbs and delays.

For me, using scenes as a “workaround” is more than good enough.
Decent signal path programming presumed, I can switch between a multitude of sounds just by bypassing and/or activating certain blocks or splits, e.g. 5 completely different sounds based on two different amp models is no problem at all, and it’s more than I’ll ever need for one single song.
If the next song needs completely different sounds again - I switch the preset in between the songs.

However, if your music is that complex that you need 10 totally different sounds switched gapless per song and be able to change any parameter on the fly, this won’t help you. But then, what did you do before digital amp simulation existed? You’ll have to make compromises either way.


Hi! How are you guys?

The problem is, the normal in my case is play without setlist, i need a lot of sounds to play minimally any kind of music (minimally ). I aways create presets in my loop midi controller like…

  • Clean or stage 1 or stage 2 or stage 3 or High gain

Combine with …

  • Chorus or tremolo or Leslie

Combine with …

  • Short reverb or Short Reverb Short delay or Short Delay + long Reveb or Long delay +Long reverb

So… A lot of possibilites. Thanks my friends!

Since the Fractal FM9 now has gapless switching between presets, scenes and amps the QC should get it to. Both units use a pair of the same chip, so ‘it isn’t possible technically’ isn’t a valid reason to not implement it anymore. :innocent:

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There’s a lot more to these devices than the processors used. The FM9 “limits” the amount of different blocks you can have in a patch and as far as I understand it, it has all the blocks in memory all the time. This means that you can’t have let’s say three amps, three cab blocks and three reverbs running at the same time unlike on the QC. However, this might be what enables them to have gapless switching. I know which I prefer, but I can see why some users need to have several amps and cabs running at the same time for processing more than two imstruments for example.

In short, I wouldn’t hold my breath for gapless in the QC, especially considering the glacial pace of development.


I would guess that the QC also has all blocks of a preset in the memory all the time, because scene switching is gapless. I’m totally fine with only two amps at the same time if that gives me gapless preset switching. Maybe let the user choose in which mode he wants to use presets and activate / deactivate a limit.

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Logically it has everything in the current patch in memory while the patch is loaded. Then when the patch is changed, it clears the memory and loads in the blocks needed in the next patch.

Since you could make a preset that has 12 capture blocks and 6 reverbs with a freeze block and then a preset with one amp and 20 choruses, it can’t have everything loaded at all times.

Sure. But I doubt that the FM9 holds everything in memory all the time because you can switch between every preset at all time. With the setlists feature you can even switch between specific scenes of different presets. It would have to hold every amp, effect, etc. that it provides in memory all the time if that would be the way they implemented gapless switching with the last update.

As I understand it, It holds all the possible blocks in memory. So the FM9 always knows that a preset can contain any combination of the possible blocks (2 amps, 2 cabs, 2 reverbs etc). The settings within the blocks can change between presets/scenes/channels. This way there’s less data that needs to be loaded when a preset is changed. I could be totally wrong here anyway. :joy: The QC needs to figure out how many instances of any particular block is in a preset every time a preset is loaded.

This is the one of the very few things that I miss about my GT-1000…

I would be perfectly happy just being able to switch instantaneously to the next preset in a setlist.
I’m sure most people could deal with that too (obviously more would be better though).


Nah, that doesn’t make sense. If I have every block existing in the FM9 used at least once in any preset it would have to hold every block in memory, because the software can’t know which song on the setlist / preset I will switch to next. The FM9 doesn’t work with ordered lists of presets where you can only go to next or previous one, instead you can change to whatever preset you have on the device. Therefore that can’t be the their approach.

I too think that would totally do it for most of us. One would just have to build a setlist before your gig and you are good to go. But additionally FM9s way to arrange setlists by choosing single scenes of different presets for a single song would add so much on top of that.