On a 3/4 size guitar, the scale length is shorter, which means that the distance between the frets is smaller compared to a full-size guitar. As a result, the frets on a 3/4 size guitar may not align precisely with the same fret positions on a full-size guitar, especially for higher frets.
Therefore, it's essential to adjust the capo placement on your 3/4 size guitar to ensure proper intonation and sound quality. You may need to experiment slightly by placing the capo on different frets until you find the best position that produces accurate and clear tones for the desired key.
It's also worth noting that different capo designs and materials can affect the placement and tension on the guitar strings. Some capos may have slightly different curvature or tension adjustment mechanisms, which may require slight adjustments to achieve proper fretting on a 3/4 size guitar.