In Looper Location = Post, where exactly is it inserted? [solved]

elemefjot · Nov 6th 2016

I have observed that when I record a loop with one rig, then change rigs, the sound of the recorded loop changes. I thought that "post" would mean after any sound coloring stage. Isn't that true?

Details: I observe so through Power Output, with Monitor Cab off, using a Guitar speaker cabinet. At the same time, I observe a sound change with some rigs when I switch the Cabinet section off (although it should already be off with "Monitor Cab off"). If there is such a sound change, it will be the removal of strange noises when I 'really' switch the cabinet off. To me, this indicates an insertion point that <fuzzy>somehow involves part of the Cabinet simulation</fuzzy>. I know this is not logical because post should at least be behind reverb, which is behind cabinet.

Update: There is a similar sound change while playing guitar/not using looper, when I switch the Cabinet section off with "Monitor Cab off" but it just lasts about 1/10 sec.

elemefjot · Nov 8th 2016

No idea anywhere?

Sharry · Nov 9th 2016

Quote from elemefjot

No idea anywhere

The reference manual could give you the answer!
Pre = after input, (unprocessed guitar signal)
Post = before output (after reverb)

elemefjot · Nov 10th 2016

Thanks, I've read that. However, based on my observation, that doesn't seem to be true, so I thought I'd ask the pros.

Rome · Nov 11th 2016

This behavior has been noticed several times before but no one from Kemper bothered to clarify this.

It seems like the cabinet is actually the last sound forming unit in the effect chain. This makes sense as you otherwise would need to process the entire post effect section twice, one time for the dry monitor out and one time for the main out with cab sim.

So the signal is split after the reverb and before the cab to go to the looper. This means that the looped sound has no cab sim applied to it. When it gets back from the looper then it's fed through the current(!) cab sim and copied to both the main and monitor out. This seems to be true for the Monitor Cab Off / Main Cab On configuration. The normal configuration seems to work differently.

At least that's my observation.

This is not as easy as it sounds. To get it right you would need two loopers in parallel. One records the signal with the cab sims of the rigs and sends the result to the main out and the other one records the signal without the cab sim to send it to the monitor out. This requires a lot of precious memory so the the KPA's current behavior is a compromise. But that only affects the monitor sound so it is tolerable.

elemefjot · Nov 13th 2016

Thanks for that information, @Rome. I do understand the argument about the need for double processing, that's true even without a looper. However, I would be disappointed design-wise if the cab sim was indeed the last stage. I might check by applying a large delay and then see if the delayed sound changes when I switch to another cab. Following your explanation, it should. I'll update this thread later.

Share