It sounds like you're looking for a USB sound card adapter that supports 7.1 surround sound, and comes with a cable. These types of adapters are used to improve or upgrade the sound capabilities of your computer, especially when the built-in sound card does not provide the features you need.

Here are a few things you might look for when searching for a USB sound card adapter with 7.1 channel support:

1. Compatibility: Ensure the sound card is compatible with your operating system (Windows, macOS, Linux) and any specific hardware requirements.
2. Audio Output: Look for support for 7.1 channel surround sound to get immersive audio experiences.
3. Connectivity: Check if it includes a USB connection and cables (usually comes with a 3.5mm audio jack or RCA outputs).
4. OEM (Original Equipment Manufacturer): This typically means you're getting the adapter without a branded packaging, which may be cheaper but still of the same quality.
5. Driver Support: Ensure the sound card has reliable driver support for the most seamless experience.
6. Additional Features: Some sound cards may include features like volume control, mic input, noise-canceling, and virtual surround sound settings.

If you'd like, I can help you find a specific product or provide links to popular online stores where you can check them out. Would you like that?