Hi oscar, it was a while ago now and I've since sold it to a very happy new owner. If you take the lid off, and locate the RAC jacks, follow the circuit back to the first little capacitor. I think it's dark green by memory but could be wrong. It's a tiny tear drop shaped thing. Just snip one leg on both the left and right channel. Alternatively, unscrew the circuit board and locate the solder joint and unsolder just one leg opening that circuit. This way it is reversible. It's a very good upgrade and takes away the apparent veil that that model tuner has.
Hope this helps,
Cheers James.
Hope this helps,
Cheers James.