[sdiy] The fatman is finished...

[Scott Gravenhorst]

Hi Gabriel,
What test equipment do you have access to?  A scope is really helpful if 
you have on or can borrow one.

The MIDI LED flashing is good.

Does the GATE LED come on?

Have you tried using each MIDI channel one at a time each in turn?  (If 
there's something not right with the dip switch, you'll discover it this 
way).  If you find a DIP setting that causes the GATE LED to light when 
a key is down, you've got the MIDI channel set to the one the FatMan is 
actually listening to.  If the setting doesn't look right, there's 
something amiss with the DIP switch.

The GATE signal is required or the ADSR won't cycle.  The ADSR supplies 
the required signal to the VCA control input.

I read your other message, sounds like you have at least used a signal 
tracer.  The VCOs output a constant signal regardless of whether a key 
is down or not.  Check the output of the VCF, it should also have a 
constant output.

Let me know about the above questions, I'll have more depending on the 
answers.

Gabriel Lindeborg <gabriel.lindeborg at sverige.nu> wrote:
>Hi!
>
>I'm almost done with my initial assembly of my Fatman.
>
>Problem:
>It recieves MIDI data(LED flashes), but does not send anything to the 
>synthpart as it
>seems.
>
>Troubleshooting done:
>Checked the ICs, all are turned right and no bent legs.
>Checked other components, all have the right values as it seems.
>All soldering points looks fine.
>The thru port sends MIDI data.
>The osc.1&2 sounds fine, it's allways on (as if gate was allways on) and
>a different note every time I turn the fatman on.
>The panel controls works fine for OSCs, VCF and VCA.
>
>Any ideas?
>
>//Gabriel
>
>
>

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-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
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