How does Frank Zappa get that creamy overdriven electric guitar sound on his Freak Out! album?
In 1966 distortion was very new. It was often generated by overloading the console or tape machine or a combo of both. Some compressors also contributed distortion and sustain as well. The tools were primitive but they made cool sounds.
If I remember correctly, he overdrove the console to get that " square wave " distorted tone ( he plugged his guitar into the recording console and turned the gain all the way up ). Depending on what gear he used and where he recorded, I can't remember exactly.