right, I am confused. Why are you trying to connect the audio jacks of the TD3 to the amp? this can only give you the output of the module, bypassing the computer altogether. But possibly I misunderstand the connections you describe.

The only thing to be connected to the module (besides the triggers) should be the MIDI out port to the ‘usb to midi cable’ (knowing what MIDI interface you have would help us help you).

This will get the MIDI signal inside your computer, assuming you have the correct drivers for it and it is recognized in Toontrack solo (check the Options > MIDI Devices entry).

On the way out, sending audio to your amp, do you get any sound if you click the drums in the interface? If not do you ‘see’ a signal in the Toontrack solo mixer? have you checked which Audio driver is in effect (check the Options > Audio > Audio Devices entry).

Anyway, even with a generic ASIO driver, I might as well warn you upfront that, even if you get this set up to work, the latency (delay in hearing what you are playing) will be quite difficult to get used to. You really should invest in a dedicated audio interface, your RealTek Soundcard is just not going to cut it for any serious work and may seriously compromise your enjoyment of the product.