I have been working on modding some Line 6 DL4's for some friends. I have been looking into what modifications really make a tonal difference in the pedal. I am really open to any ideas anyone has. I figured out how to put on an expression knob and an external tap tempo jack that works both ways (the tap tempo jack is cool if you want to use the tap button on the dl4 to control another delay like a dd5 or something. I am writing up how to do those mods now. Questions.....
Does anyone know how to make an expression system switch. Adding a 3dpt switch with led. I have it to use a switch with an 10 resister but I am unsure how to power / wire the led?
Anyone have any clue's about tonal mods?
I found you can remove C1, C36, C23, C24) and reduce R36 and R37 will take care of the volume drop issue.
Hopefully I'm going to take apart one that already has some mods and I will post my findings.
If be interested in what you find since I'm about to rip open my dl4 too. the tap tempo jack is a good idea. I was trying to figure out a way to control both my dl4 and dd20 with the same external tap but your idea saves a lot of board real estate. One mod I'm excited to try is the feedback option which feeds one of the stereo outputs into the input again to get some really crazy delay noise
Please let me know if you find out anything about that feedback knob. The tap tempo is super easy all you need is a jack and two wires. You soilder the jack onto the tap switch on the dl4. I recommend taking out the battery compartment and using that space to mount your jack. I'll post pictures when I get home
Here's a write up on replacing the switches.
http://www.diystompboxes.com/smfforum/index.php?topic=74735.0
http://freestompboxes.org/viewtopic.php?f=10&t=6255&p=67072&hilit=dl4#p67072
double preset mod
http://kyleagee.com/?page_id=105
another Jack/tap tempo write up