MIDI-Thru problem ?

[Michael Buchstaller]

Hello dear listmembers,

i am again here to pest you with my silly questions:

After some struggling with various embedded processors and much
help from you, i finally mamaged to biuld my first DIY MIDI device, a simple
MIDI note --> 16 Gates converter box.
It just works fine, but then i wanted to add a MIDI-Thru jack. So i looked at the
MIDI.org schematic at http://www.midi.org/images/midihw.gif
and added the output according to this.
My circuit ist here: http://www.takeonetech.de/midi.gif

OK, the inputs to my onboard CPU does work and recognizes all MIDI data
without problems, so i do think that there is no problem in the input stage - the
signals do also look fine when i look at them with a scope.

But MIDI gear hooked up at the MIDI-Thru connector receives only garbage
and erroneous data. After double-checking all parts, connectors and cables
and verifying that the data at the thru-connector looks to me absolutely the same
as the on as then in-connector, i am absolutely clueless.

Has anybody encountered such a problem yet ?


-Michael Buchstaller