Thomas Henry UD-1 and MIDI2SDS(X) compatibility issue

[furio]

Hi all,

I have a compatibility problem with the TH UD-1 and ED103 MIDI2SDS(X) by Paul Maddox (Elby Design).

The problem is this:
if the UD-1 DrumSynth is connected to the MIDI2TRIG interface... when a trigger impulse is coming to the UD-1 ...the trigger impulse comes back to all connected other Jacks and all connected LEDs bright and all drum modules sounds all together the same sequence for the UD-1.

I have also build the BASS++ and it is working fine with the same interface.

Is it possible to remove R34(1M) on the UD-1 Trigger Imput without damage too some component (like the BASS++ Trigger Input)?

Or any other suggestions?

Thanks!

[State Machine]

This is a bit suspicious to me as the trigger circuits for hte UD-1 and Bass++ are identical except for a single 100 ohm resistor that should not make any difference. Have you double checked you resistor values and any other components in the trigger circuit, including the panel wiring?

The 1M resistor is there to create a narrow wpulse when a trigger comes along so I would not recommend removing that.

While monitoring the negative input of the trigger comparator, and turning the trigger sensativity from full CCW to CW, you should get a measurement of 0 to about 4.7V.

Bill

[furio]

Hi there Bill

Thank you so much for your advise! I am sorry for I made a mistake in my writing, seeing that I do have R34 on both. I have just discovered that my UD-1 PCB has been re-modified by fonik from the original schematics. Most probably I would first need to find the difference to restore the original TH Power design.

I made it from this PDF http://electro-music.com/forum/viewtopic.php?highlight=ud1&t=13207 a few months ago, seeing that you could not sell me a Bord or a Kit, and my thought was that as a beginner (me) it is too difficult to design. Quite honestly spoken the Bass++ was my first PCB self-design, but works very well! Only now I came to the understanding how simple the UD-1 is.

Furio