Hi Roger
I converted a WRA 200 a couple of years ago, I can’t remember having any issues with the audio side of things.
I assume that you have fitted a wire from terminal #2 Vac to # 4 as shown in the manual, only other thing I can suggest is check that the contacts in the Audio control relay are clean, making a good circuit & closed when they should be.
On Seeburg SC’s I clean the contacts then close them manually and secure them with a small cable tie so the contacts remain closed, I also disconnect the trigger wire from the relay so that it doesn’t buz or get hot.
Cheers Scudie