There is none.
For vocals I’ve been able to get pretty nice distortion (without losing total intelligibility) with this procedure:
Splitting the input, slamming the second input channel just the right amount through the dual stage valve thingy, then slamming again to taste through the 1176.
Ad a gate for “stabbyness” if you want, and then blend to taste with dry input.
For other inputs then vocals? I don’t know. Some kind of distortion FX in the rack would be nice.