I just bought an line6 M9 and I want to control it with the FX-17
Googling it i found there's already been some experiments with it but no conclusive information, except that the mod would be but a simple change of two resistors.
The values of the build in voltage divider.
Can this information in anyway be confirmed ?
And if so can you point me to the 2 resistors to change on the photo (sorry about the quality)
Better Resolution :
Thanks.
If you plug a cable into the exp input without any pedal it measures around 3.15V without any load. A reducing resistive load will reduce the voltage progressively down to 0V.
Within limits, the EXP input is not critical about the range of operation - it appears to learn the range of resistance/voltage swing and calibrates its position dynamically.
But... if you exceed a certain resistance (and therefore voltage) the M13 seems to get confused about the pedal connected and it stops operating as a controller even in the sweep range which worked Ok before the resistance/voltage limit was reached.
I found this out with an Ernie Ball 250K pedal - it works heel down but as you increase the resistance towards toe down it gets to a certain point where the calibration gets screwed and thereafter returning to heel down no longer works. This is an odd quirk but my guess would be if you apply a voltage of greater than say 2.3V or whatever the exact threshold is, you will suffer the same problem.
If my calculations and assumtions are correct - with the L6 pedal max being only 10K, the max voltage seen across the EXP input in that case will only be 1.5V - so you should be able to reduce your controller voltage to 0-1.5V max and still get it to work OK.
I'd be pleasantly surprised if any M9/M13 product expert is prepared to give you their blessing regarding connecting any active device into an expression pedal input - but would be interesting to hear their opinion on this.
BTW - here's a tip for any Ernie Ball (or other) 250K pedal owners - I made up a special jack lead with a 33K resistor between tip and screen in one of the plugs so I could use this pedal without the problem - although the taper is not 100% linear it becomes quite useable with the M13 with this simple custom cable...
borislavgajic wrote:please could you post trace side photo....?
you can add one transistor if you need bigger voltage swing for controlling .....
thanks
Boris
I don't have a photo showing the trace side. I hope the schematic + this photo will suffice.
I need to lower the output voltage from 5v to around 1.50
OR if this "mod" could work i wont need to replace anything :
...Yes they do. I just tried it. It works. I also figured out how to use mine for my HOG. At first mine was adjusted so that at max it was only putting out 3V, and so I adjusted it with my DMM and a screwdriver to put out 5v. When looking down at it, the trimpot on the left controls minimum and trimpot on the right controls maximum.
female stereo 1/4" to male stereo 1/8" with a mono 1/4" cable plugged in.
This grounds out the ring (which is the supply voltage from the pedal.)
Holy sh*t! This is great! I wondered if the trim pots would control the cv.
Hello again
I found out by now that it doesn't work with a straight mono cable , mono jack to mono jack.
But to simplify things, wouldn't it be exactly the same, if I put a stereo jack 1/8" on my mono cable and just ground the volume outlet at that end of the mono cable ?
Can anyone tell me the value of the large yellow electrolytic cap near the right hand/lower trim pot in the pcb shot?
The schematic keeps freezing up on me on my computer. I'm looking for an electro near the trim.
I have one of these given to me that isn't working and I'd love to get it running. That cap is missing on my pcb.
Thanks!
candletears7 wrote:Can anyone tell me the value of the large yellow electrolytic cap near the right hand/lower trim pot in the pcb shot?
The schematic keeps freezing up on me on my computer. I'm looking for an electro near the trim.
I have one of these given to me that isn't working and I'd love to get it running. That cap is missing on my pcb.
Thanks!
Are you talking about C5? It's 330U. It's a power supply bulk cap.
hello, can anyone send me the pdf of the schematics ?
It looks like it's not possible to find it online on the same addresses which were given.
Thank you,
Luca
