Disabling the speed control on a Thorens TD 125 MKII

I was just trying to demo a Walker Audio Precision Motor Controller on my Thorens TD 125 MKII.  What I found is that the speed control on the Thorens takes over speed control and does not allow the Walker to do it's job.  Does anyone know how to disable the speed control on the Thorens?  I am not sure this is even possible, and am not about to go cutting or splicing wires unless I know it is possible and I know exactly what I am supposed to do.  Thanks.
Don't do that!
Speed control is part of 3-speed electronics and frequency generators supplied to the AC synchronous motor of the deck. Not possible at all.

That is definitely what it seems like.  I am bringing the Walker back tomorrow.  Probably pick up a Phoenix Engineering Road Runner tachometer which I just tried, to dial in the speed accurately.  Thank you for the input.