This bank of patches for the Yamaha DX9 was converted from an audio file of casette data posted by user18081971 on soundcloud, which you can find at https://soundcloud.com/user18081971/dx9-20-afx-voices. The cassette data was loaded into a DX9 and the bank was dumped via MIDI.

This bank can be loaded into any Yamaha DX7 or DX9 equivalent synthesizer, including the DX7II series, the TX7, TX802, and TX216/816 synthesizers. It is also possible to load these patches on an SY77 or SY99 with the appropriate software. Dexed, a free VST which simulates nearly all of the hardware and features of the DX7, can also load and reproduce these voices with great accuracy. While it is possible to load these patches in FM8, FM8 is not strictly a DX7 simulator, and FM8 cannot properly reproduce most of these patches.

Even though the patches in this bank were made on a DX9, it can be loaded into a DX7 or a DX9 because of the similarities in hardware and patch parameter storage. This bank is only 20 patches, the maximum number of patches in a DX9 bank, so if it is loaded into a Yamaha DX with more than 20 patches per bank such as a DX7, patches 21 and up will be identical to patch 20.

Please note that even though the DX9 is a 4-operator FM synthesizer, these patches are not compatible with any other Yamaha 4-operator FM synthesizer due to the fact that DX9 shares the same patch data format with the DX7, and has the same envelope generators as a DX7. It is possible to convert the patch data to a 4-operator friendly bank with TXConvert, but the complexity of the patches is lost in the conversion from 8 envelope generator parameters of the DX7 and DX9 down to 5 parameters of the newer 4-operator FM synthesizers such as the DX100 or TX81Z.