SRX Cables come standard with the most potent and musical UEF Tuning Bullets in our company's 30-year history and work 100% outside the signal path. Both Gold and Silver bullets are handcrafted in our Southern California Factory from carbon fiber and aircraft aluminum with the Gold option plated in 24k Gold not only for aesthetic beauty but also to help voice the bullet to its intended role as the most musical option for specific systems. To use SRX Carbon Fiber Tuning Modules, allow your SRX cables to settle into your system for 48-72 hours, and then experiment with your two options on a cable by cable basis. Start by inserting a Gold Bullet and then compare to the Silver option and select the variant that makes music in your system. Gold Bullets have a warm and liquid balance that is also more open and transparent than our other warm-biased tuning bullets. While Silver is more extended and detailed but the option that will work best and sound neutral is totally system dependent. If you voice your SRX cables one pair at a time, you will find one color that works best in most applications, plus a few that perform better with the alternate option. This process is how you will get the best from both Gold and Silver bullets when arriving at a bespoke cable loom voiced for your unique system.