A (possibly brand new?) Line 6 DL4 mod

Do-it-yourself pedal building

Moderator: Ghost Hip

Forum rules
The DIY forum is for personal projects (things that are not for sale, not in production), info sharing, peer to peer assistance. No backdoor spamming (DIY posts that are actually advertisements for your business). No clones of in-production pedals. If you have concerns or questions, feel free to PM admin. Thanks so much!
Post Reply
moogboy
committed
committed
Posts: 191
Joined: Mon Feb 07, 2011 9:27 pm
Location: Detroit, Michigan

A (possibly brand new?) Line 6 DL4 mod

Post by moogboy »

Alright, so, to make myself feel a little better about this whole venture, I'm gonna just explain what I want to do and why first.
I want to be able to...
1) do live, on the spot one shot looping/sampling with Line 6 DL4's (I have three that I'm going to do this to, assuming this works at all).
2) trigger said loops the traditional way, with the footswitch as given to me by Line 6. Eventually I'll do the footswitch mod but for the moment I'm okay with what they give me.
3) ******THIS IS THE NEW AND EXCITING BIT******* trigger the oneshot samples I've created with the modular synth that already forms the backbone of my live rig.

Technical details about this endeavor that I have amassed in the last 35 minutes of mucking about with almost a semester of formal circuits training:
The DL4's switches are normally closed and open when pressed, cutting the 3.3 volts and triggering the loop. Shorting the two connections makes the loop trigger, which is the exact opposite of EVERY SYNTHESIZER THAT HAS EVER COME IN THE WAKE OF THE ORIGINAL MOOG SYNTHS (I'm going to meditate on Line 6 and Moog being comparable based on this one trait alone for a solid 25 years). This is dumb, and it makes me mildly perturbed (just enough to make grumpy faces in the background of his or her photos) in the general direction of the person at Line 6 tasked with designing that part of the DL4. I only think it's dumb because what I want to do would be stupid easy if the loops were triggered by a Logic HIGH instead of LOW. Since all my synths and gear that I'd be using in this context uses HIGH for triggering, I think I need to add some extra stuff to what I was hoping would be a pretty simple mod.

So, kind and gracious DIY people, here are my questions:
For the modular, external signal triggering the loop, I think the best way to go about it would be feeding the input signal into some kind of inverter/NOT gate (so that when the trigger signal spiked up, the output signal went low) and then regulated/divided it so that it didn't blow up the DL4's circuitry that's only expecting 3.3 volts. Does that make sense/is that what you would do/am I missing anything about that scenario that would destroy stuff?
How do I set things up so that the original behavior (press footswitch, loop gets triggered) is also available with the aforementioned external triggering? Is it just a matter of connecting it so that the footswitch and external triggering are in parallel? Or should I feed both of them into an OR gate and invert that signal?

Thanks in advance for your guidance and sage wisdom!
(first post!)
I play guitar and modular synthesizer in Juggable Offense.
juggableoffense.bandcamp.com
User avatar
oscillateur
IAMILF
IAMILF
Posts: 2014
Joined: Sun Oct 02, 2011 6:16 am
Location: Tokyo
Contact:

Re: A (possibly brand new?) Line 6 DL4 mod

Post by oscillateur »

It looks like what you need is a V-trig to S-trig converter. You can do that with only a couple of components, there are schematics around for that.

And for the record. Korg also uses S-trigs. And Hz/volt too :)
Post Reply