EHX - 8-Step Program - Clock to Gate Out Modification
Posted: 03 Apr 2015, 12:25
Hi all,
Last night I finished a modification on my EHX 8-step program CV sequencer. The unit offers no gate or clock output stock. Opening up the back reveals a clock out and ground solder holes next to each other.
I originally connected the jack for the external Foot Controller* (*sold separately- it is labeled FC on the unit. It's the upper left jack in the above picture) directly to the clock out and gnd pins on the pcbs. This outputs a 50% duty cycle square wave that corresponds to the unit's clock (as well as the clock divider setting). The main issue I had is that I wanted this to function as a gate. I worked up a modification last night to create a gate signal from the clock out.
This is the basic schematic. I use NI Multisim- everything outside the box was just used for simulation purposes- the necessary modification is in the box.
This is a shot of the way I worked it up for my unit. I soldered a x2 female header to the clock out and ground pins on the pcb and then created a little add-on board with a x2 male header so that the board was removable. I also added a x2 female header to my add-on board to act as a pass-through for the unstitched clock pulse, so that I could drill and add another jack for a clock-out in the future if I so desired. I used the foot controller jack as the gate output because it was easy and I won't be using the foot controller (all presets are accessible via midi, anyways).
It works very well with all of my modular gear. It's a handy little $90 analog sequencer with 100 presets, programable glide and completely programable/controllable via MIDI... and now it has a true gate function!
I hope this helps- I was looking all over for a mod like this for a bit and could never find it, so I thought it might be worth creating myself. This is my first mod, BTW. I also have the Rev. C pcb in my unit, so please let me know if it works for you with any other revision pcb board- i'm not sure how they differ.
-Ben
Last night I finished a modification on my EHX 8-step program CV sequencer. The unit offers no gate or clock output stock. Opening up the back reveals a clock out and ground solder holes next to each other.
This is the basic schematic. I use NI Multisim- everything outside the box was just used for simulation purposes- the necessary modification is in the box.
I hope this helps- I was looking all over for a mod like this for a bit and could never find it, so I thought it might be worth creating myself. This is my first mod, BTW. I also have the Rev. C pcb in my unit, so please let me know if it works for you with any other revision pcb board- i'm not sure how they differ.
-Ben