Spektrum transmitters do not connect to computers as a USB joystick device, if they connect at all it is as a mass storage device and as such over USB they will not work with any simulator.
VelociDrone does not currently have 3.5mm audio connectivity it was removed in the 1-12 release onwards and we really don't recommend using it as the connection via this method is laggy / high latency and ruins the experience in the simulator.
For Spektrum you are best using a separate hardware dongle from ebay to convert the 3.5mm jack into a USB joystick connection, they are less than $10 and work very well.
You can connect using vjoy and smartproppoplus just using the mic input on your PC, however, we strongly advise against doing this it is a very laggy connection and ruins the experience.
Orange and Horizon do a wireless simulator dongle which works well and this is a good option.
We usually recommend this hardware dongle, which is normally advertised as a 22 in 1 simulator dongle on ebay. This takes the 3.5mm connection from the tx and turns it into a USB joystick connection....