Quote:
Originally Posted by Ted Kendall
...One point I haven't solved to my entire satisfaction is whether cassette tapes lose enough HF with age to affect Dolby tracking, or whether the observed dulling at the top end is the result of incorrect line-up or oxide shedding. The NAD play trim feature struck me as a sensible real-world solution.
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Yes hard to know the exact cause in a particular tape. As you say, it could be the recording was never lined up in the first place. It could be due to overbias, wrong pre emphasis, even just a dirty or worn record head.
I agree the NAD/Yamaha "play trim" feature was a sensible idea for consumers to try and correct mistracking but it was necessarily simplified. Left and right channels were ganged together and the adjustment of highs was limited, and could only help with mild hf mistracking. I've had to push it further with independent left and right channel adjustments, and generally more targeted corrections - which sometimes still aren't enough, and one has to abandon decoding, as you say.
My impression is that the techniques for attempting to get a Dolby encoded cassette to track correctly aren't that well known.