JVC HR-S7500E head switch point?

[mts1]

Hi, guys.

I've got a VCR to play with. It's JVC HR-S7500E.
I adjusted the head switch point and I've got a super picture! I have 2 original tapes and it shows!
One of theses tapes had Hi-Fi audio, and I expected to get some noise, crackle, distortion, hum, whatever.
However, there was nothing alike. It was just a good sound.
So, my question is why? Was I just lucky? Or adjustment was too small to hear a noticeable effect? Anything else?

Thanks.

[latreche34]

Well, you can't complain about good. But yah some tapes are recorded with good equipment in perfect alignment so to mess it up it takes a lot, Having said that, try other tapes especially low speed tapes to make sure your switch point is dead on, you can't make adjustment on good tapes.

[mts1]

Well, I don't complain about good. I'm just afraid it's gonna hit me back when I need it the most.
Unfortunately, I don't have many tapes with Hi-Fi sound. And we're way past the times, when I could get a bunch from a bin in a grocery store for a buck or two.
On the other hand, the one I have is professionally recorded (wedding).
I could record one using untouched (by me) VCR, but would it be more reliable than the one above?

[latreche34]

You can't align a VCR on it's own recording unless they were previously recording on it when it was perfectly aligned.

[mts1]

I guess I wasn't clear. When I said 'untouched (by me) VCR', I just meant another VCR.
I guess I could record some video pattern (for calibrating or, at least, to see what I'm getting back ) and silence using different speeds.