A manual says that [vd~] is smoother than [delread~] because the first does interpolation. I don't know why, but my patch NUMBER-[sig~]-[vd~] does "clicks&pops" at changing the number, exactly like [delread~]. Why?
Thx

when you go from a number command straight to a signal using [sig~] the changes are just too abrupt. try

number
|
[$1 30[
|
[line~]
|
[vd~]

this should smooth out things, but it will give you a weird pitch changing effect on delay time changes. increasing/decreasing the 30ms should increase/decrease the pitch effect.