I built this with the Split 'n' Blend circuit on the Drive A side and it appeared to be working correctly.
It was alright with the Drive knob to about 2 O'clock (65%) then it just got bloated and Fuzz like.
I went back over what I had done which was putting the Split 'n' Blend Circuit First followed by the Hot Wired Drive A side, ie Split 'n' Blend Input - Split 'n ' Blend Output to Hot Wired Drive A Input.
What the issue was is the Pull Down 1M resistor from Drive A Input to Ground was now in the middle of the Circuit.
By removing the 1M Pull Down Resistor & placing it at the Input of the Split 'n' Blend which does not have the Pull Down 1M resistor to Ground on the Layout now works correctly.
Hope this Helps those implementing the Split 'n' Blend or Other Circuits into their Circuit to be aware of Input Pull Down resistor placement.