I bought this to process STEREO SOURCES from SYNTHS into amp simulations and distortion.
On paper, all seems great (impedance matching, stereo input and outputs, flexible routing and all), but on practice, 95% of the effects are mono only, which shouldn't be an issue since you can split the input in 2 channels and process them separately.
But then you'll have phase issues (left and right channel cancelling each other) unless both channel effects are set exactly the same, but yeah, that was expected.
However, what wasn't expected is: you can't start with a stereo effect, split the signal to left and right channels, process them separately and recombine them in a stereo output because, even though it's supposed to be supported, there's a bug that makes the right channel muted (because the mono effects expect the sound to come from the left channel only, so they just ignore the signal from the right...)
What you CAN do is split the stereo signal FROM THE START into 2 channels, left and right, process them separately using mono effects and then combine them into a single stereo channel to apply a stereo effect (like reverb) before output in stereo.
That works, but you can't place any stereo effects before splitting the signal in two, which limits the use for stereo sources A LOT.
Also, since nearly all effects are mono only and you have to duplicate them to process stereo sources in stereo, you'll have to manually copy paste every edit you make in one channel to the other, which is very cumbersome to fine tune the effects or even to adjust them after the preset is done, because there are only 3 assignable knobs and you'll have to use 2 knobs for each parameter you want to adjust, one for the left channel and the other for the right channel.
All of this issues aren't a hardware limitation of the pedal, but errors in the software of the stereo processing.
Even though the hardware is clearly capable of stereo processing and is advertised as such, it's clear the manufacturer didn't pay any attention to how it actually performs with stereo inputs.
The physical knobs are VERY cumbersome to use because they are stepped, very stiff, and change the values either too slowly or too fast.
And that's because the knobs don't have a linear response: they change pace depending on the speed you turn them, which makes them completely unusable for tweaking things like a delay timing in a live performance.
I guess they were designed to set things once and don't change them live.
I end up using the touch screen to adjust the values with a slider, but even then it's still unusable for tweaking parameters live because the sliders are just too small in the screen and you can't be precise at all.
The touch screen is good though, and the user interface is alright, even though it's quite complex. (but that's inevitable when you want flexibility)
The effects are good but not amazing: the reverbs in particular are not the best there are, honestly, so you will not replace a Strymon Sky with this pedal, but they are usable and some of them are actually very good (but not the shimmer reverbs, which sound "stepped" instead of smooth, sadly).
The chorus, phasers and the like, even though they all have a stereo output, can't process stereo inputs, which is really sad.
The amp simulations and distortions are REALLY GOOD though.
Compared to ZOOM multi effects pedals, the effects in general are not as good, but the amp simulations and distortions are much better, which is the reason I bought the Ampero in the first place.
At the end of the day, I bought this unit for dual channel amp simulation, gain staging and distortion. And for that, it delivers and I'm satisfied with it, but I can't recommend it for stereo processing in general with the current state of the software, and I don't expect it to improve, since it's clear the unit is aimed at guitarists alone and stereo input is an afterthought.
