Hi Eric
I have played around with it today it is working to a degree. As you said the 1.5k resistors in the bridge reduce the sensitivity but i am trying to reduce the current through the s/g and the overall circuit as it is powered by battery.I can use the other amp but unsure about connecting one to the other i am having enough trouble with one hey.Can you help with connections and do you think this would give better control.If you think there is a better circuit i will give it a go