DOD 440 opto; will a 5C3/2 work?

[Bernardduur]

Hello!

Right now I am working on a DOD 440 for a friend...... shame is that I can only order VTL5C3/2's from the store, not the needed 5C4/2's; what will the difference be if I use the 3's instead of the 4's?

[Bernardduur]

OK; small update:

I tried the DOD circuit with some leftover 3's and I can't get it to work; all I hear is the clean signal that does not differ.

Anyone to back me up on this?