Lowering the VTA typically will roll off the highs as you move below the optimal setting for the LP. The rolled off highs will result in a softer sound with less high frequency energy. Much of the noise from a scratch comes from the leading edge transient, and with less high frequency information the transient will have a lower volume. If your VTA setting was higher than optimal to begin with, it would be accentuating the noise of the scratches. Otherwise, be aware you may be losing information and accurate reproduction by using the VTA as a tone control. In any event, glad you're finding a way to make some of you LPs more enjoyable.
For a good discussion of adjusting VTA and VTF, take a look at Lloyd Walker's recommendations for fine tuning your turntable.
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For a good discussion of adjusting VTA and VTF, take a look at Lloyd Walker's recommendations for fine tuning your turntable.
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