Behringer UP100 trimpot question

[Magical_Max]

So, whilst sitting here daydreaming about a project I've been daydreaming about for the last 4 years (at least) and not doing tasks I should be, I cracked open a Behringer UP100 (picture below for those unsure of the model) and found two trimpots to the right of the "mode" switch.
Does anyone have any idea what these trimpots do or care to speculate as to what they might do before I go ahead and try it myself at a later date?

Cheers.

[Magical_Max]

So no replies came and I found myself at a loose end yesterday so had a mess about with the trimpots.
Below is a picture of the trimpots I'm talking about.



and a little closer:



It would appear that VR1 increases the depth or level of the effect, making it far more useful IMO. I've found it to be a bit weedy in the past and haven't used it for that reason.
VR2 increases the resonance from usable to self oscillating.

Signal chain for the recordings below is:
bass -> UP100 -> USB interface

Settings (in o' clock) are all in the same mode, mode 1, and with the knobs in the same place played in the same order, with the exception of the last clip because its just twiddling.

Settings:
1st - max, min, max, max
2nd - max, 2, max, 3
3rd - max, max, max, 4

Samples are on sendspace, download button is the orange button not any others on the page:
Pedal in original state, clean 1st the as above
Pedal with VR1 adjusted to 6 o clock
Pedal with VR2 adjusted to 4 o clock
Pedal with VR2 as far as trimpot needed to go to oscillate

Samples will be hosted for 30 days then removed automatically by sendspace, PM me or stick a reply on here when they go if anyone wants the back up.

Errr, yer, if anyone finds this interesting hurrah.
You might find it makes the pedal more useful or if you want a cheap noise maker (probably sound nice if you stuck a huge distortion after it, might try this myself actually) then this could be used for that too.

Cheers.