TheUltimateSwitch

This is another great hand made project, finished in 2011 - TheUltimateSwitch. Ok, almost the ultimate :)

The main purpose of this simple device is to redirect the audio signal without leaving the listening position (e.g. changing the cables manually). With push of a button, the remote control commands the receiver to turn on/off the signal relays. I decided to use the Takamisawa relays for their reliable and low resistance contact materials. Because i needed the relays to switch higher current when switching a power amp output, multiple relays were used for each channel. Thanks to this design, it is now capable of switching hundreds of watts of power with a minimal wear out.

A special care was taken to eliminate the airborne, or the solid surface transmitted vibrations, with cork damping and foam rubber. This also helped to suppress the noise created by the switching relays that were housed in a plywood box. High quality gold plated terminals (Eichmann, Vampire) with high quality cables were connected by pressure and Marigo Labs. silver solder. In order to achieve the best result with the lowest transient resistance within the whole switching device, the best option is eliminating the solder wherever possible. Solder's greatest disadvantages are higher electrical resistance and faster aging process. In this case, the solder had been used for the low level signal part (switching the Vampire RCA connectors as well as the higher level signal part, where its primary function was to secure, instead of transmit. I was able to make a mechanical clamping system, so that the audio signal was directly transmitted between the copper of the cable and the gold plated part of the connectors.

The chassis of the switch is made of die cast aluminum and the front panel, as well as the knobs, are milled from an african hardwood - Padauk. A red alphanumerical LED display shows the current settings of the switching mode (SS - signal source, AM - amplifier, SP - speakers), or switching just one channel of the selected setting. Body of the remote control is milled from rosewood and works from both sides, no matter which one is pointed on the switch. ophichus@gmail.com