The problem with the vortex tracker is that it is not the exact same format as the AYT tracker. There are some big differences that make it a tad difficult to do a direct conversion..
Vortex Samples
Each Sample row permits a pitch offset between -4095 to +4095.
AYT permits a pitch offset between -25 to +25. One can achieve a greater span through note offsets.
Each sample row permits changes to the Tone, Noise and EG flags.
AYT does provide these switches but with extra tracks dedicated to Noise and EG values, they take priority control over Noise and EG bits.
Each sample row permits changes in Noise or EG offsets in the range -31 to +31 and -4095 to +4095.
AYT provides similar but less range and with tracks dedicated to Noise and EG they take priority control of these elements.
Vortex Ornaments
Vortex provides sequences of note variations over time (arpeggio) but AYT does not provide these. Instead these are provided in the Effect.
Vortex EG Pattern column
Vortex provides a column for the setting of EG up to 65535 but AYT only permits 0 to 60. Version 0.3 does allow a bigger range by using Track H command pattern to set between 0 and 4095.
Vortex EG
The EG or Envelope Generator, Vortex music usually utilises it as a wave generator and the values the 16 bit period is set to is based on the 1.77Mhz AY clock frequency of the Spectrum. Any converted tune must convert the value to the Oric 1Mhz. These means a mutliplication of about 0.565 which means a definate loss in resolution at higher frequencies.
In Vortex2AYT.exe converter this conversion is always performed.
Vortex Pattern Notes
Vortex allows a note range of up to 96 in a single pattern but AYT only goes to 60 notes. Because AYT has 64 Effects the converter deals with the bigger range by setting the effect to +32 for notes beyond C-5. The Effects over C-5 would then be set to increment the note by 5 octaves at the start thus achieving the bigger range.
I still stand that AYT is more flexible and powerful than Vortex because it supports 8 tracks, sharing and a more logical split of AY musical elements, but i do agree it does make conversion of popular tracker music (beyond just the notes) more of a pain.