The drum channel can have multiple notes/samples playing simultaneously, thus possibly resulting in less notes being dropped due to a lack of MIDI channels. This is possible because there are no volume/pan/freq changes affecting the notes on the drum channel. Most MIDI instruments/players have a permanent drum channel, normally channel 10.
Converting in the drum channel
For a sample to be converted in the drum channel you must first assign it to the drum channel. This is done in the sample options page, either by using the DRUM switch, or by clicking on the piano keyboard (when the SAM/DRUM switch is in the DRUM position). When a sample is assigned to the drum channel, the PATCH value is the sample's base note on the drum channel. The base note is the origin from which all notes used by the sample are offset. When you assign a sample to the drum channel you should make sure there are no other samples assigned to any of the same keys. Any keys with more than one sample assigned will be red on the piano keyboard.
Suitable samples
Not all samples are suitable for conversion in the drum channel. This is because no volume/pan/freq changes can occur on the drum channel (any changes would affect all notes playing). So, for this reason samples that use instrument information (volume envelope/fadeout, panning envelope, instrument vibrato) or any effects that affect the sample's volume/pan/frequency/offset are not going to be converted 100% accurately. You may not mind losing the panning changes of a sample, but samples with volume/frequency/offset changes dropped generally sound pretty bad. You can use the AUTO DRUMS option to let 2MIDI pick out the samples that are suitable for conversion in the drum channel.
Problems converting in the drum channel
A possible problem with converting a sample in the drum channel is if the sample is played at any one note more than once at a time. Each note can only be played once at a time, so in the case of a note being played more than once at a time, the note would be played only once, and it would be ended by the first of the notes to end. Any samples that are played at the same note more than once at a time, should not be converted in the drum channel. You are informed if this problem occurs in the convert options page.