Hi, Corey, Ah yes, the Firesign Theatre tape that appeared to have been made with part two overwriting part one (but going in the other direction, I think). It was two track stereo. I suspected that this was the reason and I realize it was used to reduce erase noise. If the erase head had not been disabled, they would have lost one half hour segment instead of two--although there was a tantalizing hint to what be there, we could not find even a sliver to recover without the other program. Later designs with higher erase frequencies and especially lower waveform distortion did not need to do this. There was no longer a benefit. Cheers, Richard On 2/8/2016 12:39 AM, Corey Bailey wrote: > Other "out of the box" thinking at the time led to disabling the erase > head for first-pass on virgin tape to help the signal-to-noise ratio. > This was accomplished by switching the erase voltage to a dummy head so > that the load remained the same on the erase amp. Even tried this with > 2" multitrack recording with improved S/N results but then, the mixer > du-jour would forget to turn on the erase head when needed and record > sound-on-sound for a punch-in so, the multitrack innovation was abandoned. -- Richard L. Hess email: [log in to unmask] Aurora, Ontario, Canada 647 479 2800 http://www.richardhess.com/tape/contact.htm Quality tape transfers -- even from hard-to-play tapes.