The Amp Garage

Yes, the xformers are just for isolation purposes. The reason the use 3 is that you can use a stereo jack to connect two effect units - one on tip, one on ring - and eac of the two returns 'get' a xformer. IF you, however, flick the little switch you can alter the operation to balanced mode instead...

I cannot believe they put the relay in the summing node of the op amp. Any noise that couples in here will see the total open loop gain of the op amp. The input resistor should go between the relay and the op amp. The 49.8k's are probably the recommended load for the xformers. They could be wired a...