freestompboxes.org

I want to highpass my Infinium T5 head. In terms of a series capacitor adding a 6db treble slope to everything - so probably starting quite high in frequency.

AFAIK there is no T5 schematic at this point, but there is a V5 schematic which is very similar but has a single tone control and is not SMD.
I already have a 500pf across the volume control and other treble boosting mods, but are still needing to use an eq pedal when at TV volumes - want to really cut the lows and mids from the amp.

If i wanted to add a 6db highpass to things (and at a high frequency - some Khz), what would be the best thing to alter?

Heya!

For a pre-distortion cut, the easiest way would be to decrease C15 or simply add a tiny cap in series with the input. For post-distortion, C10 would be a good candidate.

If you tell us how your EQ pedal is set up we can advise some component values. For higher order cutoffs, C9, C13 and C4 could also be reduced.

All the best,
stolen