DAC = Digital to Analog Converter.
Yes, it’s the same as your SoundCard.
For the Player Software, try Logitech Media Server (LMS).
It’s FREE & excellent.
It’s browser based, so you can control it from your Tablet or PC.
For a small cost, get iPeng, which is a much nicer interface.
You say you have an external HDD. Is it a NAS? (Network Attached Storage).
Depending on the IT skills & your budget, you have a few options.
1) Buy a Raspberry Pi & install LMS & Squeezebox on it.
Pay the extra for a DAC HAT so you can connect directly to your Amp.
Or connect to your DAC if you already have one.
Attach your external HDD directly to the Pi.
Control from your iPad via LMS or iPeng.
Setting up LMS on a Pi needs some IT skills. More than I have.
If you can stretch to a NAS
2) Buy a NAS & put all your music on there.
LMS comes Free to download onto the NAS.
Modern NAS will play the files too, so can be connected directly to a DAC.
Control from iPad.
Yes, it’s the same as your SoundCard.
For the Player Software, try Logitech Media Server (LMS).
It’s FREE & excellent.
It’s browser based, so you can control it from your Tablet or PC.
For a small cost, get iPeng, which is a much nicer interface.
You say you have an external HDD. Is it a NAS? (Network Attached Storage).
Depending on the IT skills & your budget, you have a few options.
1) Buy a Raspberry Pi & install LMS & Squeezebox on it.
Pay the extra for a DAC HAT so you can connect directly to your Amp.
Or connect to your DAC if you already have one.
Attach your external HDD directly to the Pi.
Control from your iPad via LMS or iPeng.
Setting up LMS on a Pi needs some IT skills. More than I have.
If you can stretch to a NAS
2) Buy a NAS & put all your music on there.
LMS comes Free to download onto the NAS.
Modern NAS will play the files too, so can be connected directly to a DAC.
Control from iPad.