are old tapes out of phase ?

[wcb]

Hi, its my first post. I received my deck back from doc, with new 2 track heads by flux and re lap  4 track heads. Wow what improvement in sound. I have been playing all of my old 2 track tapes and Had hit the mono button by accident. I then notice that the vocals Had a echo effect i then tried a 4 track and it was fine, vocals in the middle . Now I'm thinking something is out of phase so i try one of Dans tapes and it played fine when I hit the mono button. does anyone else have this problem or are the old tapes made out of phase ?

[High and Outside]

Hi, its my first post.

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