Tube Guitar amp Input Transformer Removal
The input transformer is required for electrical isolation.  Do NOT remove it!

This circuit is similar to the old tube-type AM radios from years gone by.  The circuit operates directly from the incoming AC power.  If you look closely, you will see that one side of the incoming AC power cord is tied directly to the main circuit ground.

Although the AC plug is marked with (-) &amp; (+), there is NO guarantee that you won't wind up with the incoming hot (Line) conductor connected to the circuit ground.  This is a potentially lethal shock hazard should anyone touch both circuit ground and an Earth ground.

The input isolation transformer simply couples the desired input signal to the volume control while providing galvanic isolation.

Note: the metal shell on your 1/4" Phone Plugs on the guitar cord as well as the metal faceplate on your guitar are all exposed and can be touched.  Do NOT remove or bypass that input transformer!