Boss DD3-3B , digital delay pedal , 2003

[N Cook]

More a question of what is normal with these. ?
Probably an elcap problem, repaired . Its out of the box so the normal
footswitch action is replaced for testing with just a wire touched to
ground.
As this one stands, then about 0.2 seconds of contact is required for the
flipflop action to change latch action - is that normal. ?
Any less and it just momentarily flicks to the opposite state but reverts.
Also is the "hold" mode not-hold, ie the box is only on for the duration of
the footswitch being pressed and off on removal of foot, in the other mode
ppositions long,medium and short delay then latched, divide by 2, footswitch
action.

 

[D-unit]

More a question of what is normal with these. ?
Probably an elcap problem, repaired . Its out of the box so the normal
footswitch action is replaced for testing with just a wire touched to
ground.
As this one stands, then about 0.2 seconds of contact is required for the
flipflop action to change latch action - is that normal. ?

I would think not. It should be instant.

Any less and it just momentarily flicks to the opposite state but reverts.
Also is the "hold" mode not-hold, ie the box is only on for the duration of
the footswitch being pressed and off on removal of foot,

This IS normal.

I have an old DD-2

db



in the other mode

 

[N Cook]

I would think not. It should be instant.


This IS normal.

I have an old DD-2

db



in the other mode

The dd2 has a dedicated flipflop to do this but this dd3 seems to just use 2
of the 4 sections of a 74HC00 to act as a buffer to doubly invert and
nothing more, and then that signal goes to a pin on the main micro with any
de-bounce/divide by 2 function built in there, it would seem.
I've only done partial circuit tracing so that may be wrong.

 

[N Cook]

The dd2 has a dedicated flipflop to do this but this dd3 seems to just use 2
of the 4 sections of a 74HC00 to act as a buffer to doubly invert and
nothing more, and then that signal goes to a pin on the main micro with any
de-bounce/divide by 2 function built in there, it would seem.
I've only done partial circuit tracing so that may be wrong.

Did a better subcircuit determination
Using one wasted, as paired-up, input to one of the SM 74HC00 gates ,
cutting just one pcb trace and added an R,a C and a D constructed a 0.4s
monostable, pulse stretcher so now latching properly. It does not seem to
have affected the hold mode option either.
Fuller details eventually on repair2.htm file off URL below as latching
failures seem quite common with DD2 and DD3 according to the archives