MARSHALL JH-1 JACKHAMMER Mod

This could possibly be one of the best pedals ever made. It comes with True Bypass and a mode switch that allows you to switch between Overdrive and Distortion, this gives you two very different pedals in the same unit.

The only problem is, that many of the parts used to construct this pedal are of poor quality, this renders the Frequency and Contour controls almost useless.

The stock unit ships with three TL072 chips which always sound lifeless and regressive. It also uses 1N4148 diodes in its Distortion mode and Red LEDs in its Overdrive mode. Whilst the Overdrive mode can sound quite good with some tweaking, the Distortion mode is weak and boring. No amount of EQ or contour can help this mode. As a result, most people simply never use it.

At Von Lehmann Engineering, we started by replacing the three TL072 chips with three ‘Red Demon’ chips, this really brought the JH-1 back to life, increasing the volume and minimizing the noise.

Then we replaced the boring 1N4148 diodes and Red LEDs, giving the pedal two very different sounding modes of distortion. This turned the Jackhammer JH-1 pedal into a Distortion Monster with enough gain to make Linda Blair’s head spin.

We also replaced all the inferior parts with the highest quality available and reconfigured the EQ stages. This increases the volume and opens up the pedal to new tonal possibilities that spans from ‘Subtle Blues’ to ‘Extreme Death Metal’.

http://www.vonlehmannengineering.com/MARSHALL_JH1.html