Not always. In fact usually two holes are for one channel. Hi/Lo per each channel (two channels) = 4 holes For instance... My 1965 AC30 has 6 holes. There is a high input and a low input for the top boost channel.... there is a HI/LO inputs for the Normal channels and there are HI/LO for the Trem channel. I place a patch cable into the top boost “high” channel to the Normal channel “low” input.. then I plug my board/guitar into the normal “high” input. So I’m using two channels blended (Normal with Top Boost) It sounds much much better than just using one channel. The Top Boost channel is a bit bright but it has three EQ knobs to tailor the tone. The Normal Channel has no EQ and is a bit compressed and thick. Put them together and you can tailor the volume knob of each channel and the three EQ knobs to the Top Boost Channel. Together, I get the sparkly Jangle while still having that mid thick compressed Brian May eschew tone.