I have 2 separate units.
1) A PC stereo sound card unit (Audiotrak Prodigy HD2) with 2 outputs that feed into the inputs of a
2) stereo preamp/amp unit (model HK3480).

I would like to know if the DACs are being used on both units.

My assumption is that the PC Sound card uses its DAC and then that analog signal goes to my preamp/amp unit. At this point...would the HK3480 just amplify the analog signal that had already been converted by the PC soundcard? So I would be effectively bypassing the DAC on the HK3480?

Sorry I could be horribly wrong as I am quite inexperienced with electronics.

 

So I would be effectively bypassing the DAC on the HK3480?

Yes. The DAC input is digital, so if you have an analog signal, then it can't go through the DAC.

 

The PC sound card uses a DAC in order to produce an analog signal.
When this is fed to a preamp/amp it is straight analog from here on to the speaker in a typical old fashioned receiver.