An introduction to computer audio
You can't connect two devices if they don't have the same interface in common.
You need to convert.
USB to SPDIF (coax or Toslink)
If your PC has USB out and your amp SPDIF in, you can try a USB to SPDIF converter.
An overview can be found here.
- High-end 24-bit/96 kHz A/D and D/A converters for ultimate signal purity
- Converts any sample rate between 31 and 100 kHz into 32, 44.1, 48, 88.2 or 96 kHz sample rates
- Flexible format conversion between AES/EBU and S/PDIF (coaxial or optical)
- Ultra high-quality signal output with 16-, 20- or 24-bit resolution
- High-precision quartz clock generator removes jitter and corrects off-tune, incorrect sample rates
- Extremely fast tracking supports varispeed applications
- All three outputs (XLR, RCA, optical) simultaneously operational (splitter)
- Inputs separately selectable (patchbay functionality)
- All digital inputs/outputs balanced and galvanically isolated
- All analog inputs/outputs servo-balanced
Murraypro SPDIF & TOS level to AES 3 £75
Converts SPDIF and Toslink to AES
M-Audio: CO2 - Coaxial/Optical Bi-Directional Converter
- converts between optical and coax S/PDIF
- serves as a repeater to extend cable runs
- TOSlink optical and coaxial digital inputs
- TOSlink optical and coaxial digital outputs always active
- transformer-isolated RCA jacks prevent system ground loops
Available as a simple kit, it comes with an onboard 3.3V voltage regulator for a wide supply range and a Toshiba TORX 147LF optical receiver for support of up to 96kHz.
RCA to balanced
Long RCA cables are not recommended.
Here you find some products converting RCA to balanced audio using CAT5 up to 2500 ft.