With both offerings from iFi aiming to reduce unwanted noise in your system, people often struggle at defining just what each product is meant to target. Should you be using one over the other? Both? Today we discuss the differences between the iDefender+ and the iSilencer+ and what problems each product targets. Before we start we need to talk a little about USBs. The USB standard provides one benefit more than anything else. Compatibility. USB have standardised data ports, allowing a general connector to be used for various uses. Most use cases for USB is about fast data transfer such as for printers, flash drivers and others. However audio class USBs, or more accurately, USB Audio Class 1&2 devices (2 Channels@32Bit/768khz & 2 channels@24Bit/96kHz ) have a greater requirements due to the much higher throughput at high sample rates. In essence this means audio devices require much more precision than most other USB devices. The sampling rate is what really creates issues. With such a constant data stream needed to maintain a high sampling rate, USB Audio Class devices use ‘Isochronous’ transfers while other devices use ‘Bulk/Burst mode’ transfers. A sequence of events is isochronous if the events occur regularly, or at equal time intervals. Using this means that the USB schedules one transfer per available frame therefore guaranteeing the bandwidth on the USB. Because of this, any errors or electrical noise cause data loss leading to distortion or crackling sounds. To remove this we therefore must ensure that the USB signal quality is excellent and no errors occur. This is where the iSilencer and iDefender come in. The iFi audio iSilencer3.0 adapter is a device that eliminates interference in the audio signal generated by the USB port of a computer/music server/etc. Jitter, a term referring to an irregular delivery of data packets which results in cold and aggressive audio can often ruin music. The iSilencer is essentially a USB filter that aims to reduce noise and espically jitter. Simply plug the iSilencer into any standard USB port on your device and removes noise from the signal as it passes through to the DAC. The iSilencer makes use of 3 technologies to achieve this feat which are furter expanded upon in the full length article below. 1. Active Noise Cancellation® technology 2. Reduce jitter + packet errors 3. REbalance® the USB signal 4. USB3.0 technology for optimal transfer The iSilencer+ takes this one step further by reinforcing the iSilencer with the additional low ESR Tantaium capacitors for filtering. This leads to a 100% increase in input filtering capacitance and an 84% in output filtering capacitance. As well as new gold placed USB-C connectors. The iDefender tackles a slightly different problem. The iDefender plugs into your computer USB port and auto-detects if there is more than one earth and will ‘intelligently’ disconnect the computer earth for a cleaner sound. It eliminates ground loops that keep the DAC from functioning properly and compromise the transparency of the restitution. On top of saving your computer from the unwanted earth, if your DAC is USB powered, iDefender3.0 can block the computer’s power supply and replace it by an external power supply. Injecting clean power will ensure you get the maximum outof your USB audio. It significantly reduces the system noise floor and makes for better dynamic contrast, warmth and resolution. The new iDefender+ has the same upgrades of that of the iSilencer+. It uses new low ESR Tantaium capacitors in conjunction with gold plated USB-C connectors, allowing for a 10-fold increase in capacitance. For more technical details please read the full exert from iFi – iDefender vs iSilencer Full Length
About The Author
Hailing all the way from the USA, Jason runs our Wellington store as branch manager. Jason has a background as professional studio engineer and has a longstanding history on the custom installation side of the business. Jason has a great ear for what sounds good and a depth of technical knowledge.