[sdiy] Adding LED rate indicator to delay unit

[Travis Shire]

I have an old "Larson" rack "digital" delay unit I'd like to add an LED rate
indicator to the LFO just for visual indication of the repeat speed. No
service info available for this unit, but I think its just a knock off of
the Deltalab things with a rotary switch instead of the pushbuttons for
delay time. Sound feasable? I'll have to open it up and poke around with a
scope to see what I can see around the LFO. It might be some sort of clock
whick would simplify things.