ISF - what does it do?

[majikmojo]

i feel ya Jono - taking my 60 out tonight for the 5th time - so far not one issue and i'm using my pedals less and less on the OD side as i get a grip on the eq controls - still use a chorus and delay on the clean side but i am getting good clasic rock tones on the OD channels all by itself which is really pleasing me

[TomHidd1]

I also don't notice any difference between themtime card calculator