Excellent thanks for your help
FYI Jensen reccomend a transformer for this application that other companies are using with success. It is Jensen Transformer model JT-10KB-D
NB NOrmally used a 4:1 transformer for line inputs.
As it does not have centre tap sec. I assume we can use 2x27K resistors( instead of the one from the tap in the schematic) to form a virtual tap at the junction of the two resistors e.g a similar circuit configuration ( with different component values ) as used in the PZM-30D electronics ?
Thanks also for such a great range of products