@doug714 - Gordon? I'll translate for you:
"I use the Qobuz app (A subscription music streaming service) on my laptop (his PC, same as your iMAC) to a Fiio Q5 USB DAC (A DAC with a USB input connection), then mini jack to RCA (3.5mm mini connector on one end, standard RCA interconnects on the other end) to my PL (Prima Luna Audio) integrated (Tube integrated amp). Sounds great to me. If I feel like working for my music, my turntable is also connected.
Regarding the NAD Dac2, it's just a DAC, but it is wireless. It uses a 2 piece hardware setup, wireless transmitter with USB input on the source end and a DAC with a wireless receiver on the other end. It's just a DAC, but the connection from the iMAC to stereo system would be wireless, instead of using a USB cable between the two. Seems you would still need a USB cable to connect from the iMAC to the transmitter and you will still need interconnect cables from the DAC/receiver to your stereo system. Could be a good solution if your iMAC is not located close to your stereo system hardware. I've never seen/heard the NAD, so I can't comment on the sound quality.
Lastly, I would be remiss if I did not mention that you are selling yourself short regarding using YouTube as your source for music. YouTube is an awesome app, but sound quality is likely compromised and you are at the mercy of whomever uploaded your music selection regarding the sound quality. You have EXCELLENT speakers and amps. I've heard your speakers on a few occasions and they are fantastic. A subscription streaming music service, like Qobuz, Tidal or possibly the "soon to be" HiFi version of Spotify will provide better sound quality and a better dedicated music focused user interface.
"I use the Qobuz app (A subscription music streaming service) on my laptop (his PC, same as your iMAC) to a Fiio Q5 USB DAC (A DAC with a USB input connection), then mini jack to RCA (3.5mm mini connector on one end, standard RCA interconnects on the other end) to my PL (Prima Luna Audio) integrated (Tube integrated amp). Sounds great to me. If I feel like working for my music, my turntable is also connected.
Regarding the NAD Dac2, it's just a DAC, but it is wireless. It uses a 2 piece hardware setup, wireless transmitter with USB input on the source end and a DAC with a wireless receiver on the other end. It's just a DAC, but the connection from the iMAC to stereo system would be wireless, instead of using a USB cable between the two. Seems you would still need a USB cable to connect from the iMAC to the transmitter and you will still need interconnect cables from the DAC/receiver to your stereo system. Could be a good solution if your iMAC is not located close to your stereo system hardware. I've never seen/heard the NAD, so I can't comment on the sound quality.
Lastly, I would be remiss if I did not mention that you are selling yourself short regarding using YouTube as your source for music. YouTube is an awesome app, but sound quality is likely compromised and you are at the mercy of whomever uploaded your music selection regarding the sound quality. You have EXCELLENT speakers and amps. I've heard your speakers on a few occasions and they are fantastic. A subscription streaming music service, like Qobuz, Tidal or possibly the "soon to be" HiFi version of Spotify will provide better sound quality and a better dedicated music focused user interface.