Filter Tap Length
Filter tap length is the number of weighted sample terms used by a digital filter.
More taps can support a more detailed filter response, but the coefficients and design determine what the filter actually does. Tap count is not the same as an oversampling ratio.
Filter Tap Length — DAC
For a DAC, this count describes its own reconstruction filter. That filter shapes the sampled signal before analogue reconstruction within the converter’s processing path.
Compare tap counts only alongside filter purpose and operation. A separate upscaler’s count does not become the DAC’s count, and more taps alone do not establish better sound or a particular delay.
Filter Tap Length — Upscaler
For an upscaler, taps describe the filtering used to calculate the outgoing sample sequence. Filter length is one design parameter alongside the output rate and response.
Keep the count attached to the stated filter or mode. It cannot be calculated from the upsampling ratio, and comparing counts alone omits the filter coefficients, frequency response and processing delay.