Van Den Hul - Dutch maker famous for ultra-high-end audio cartridges and cabling. Wattgate - Kimber Kable outlets and plugs. UltraStat - Devices to eliminate user induced static discharges to audio equipment. Brick Wall. - Manufacturer of surge protectors, includes explanation of technology's workings and advantages. Ringmat Developments - Circular mats go both under and over LPs. RPG Diffusor Systems - Features physical room treatments, and software. Shun Mook - Offers Mpingo disks and other room-improvement devices. Shakti Innovations - Makers of Stones, passive add-ons, and also cable-ware. Marigo Audio Lab - Cable-ware and tuning dots. Bybee Technologies - Power and audio signal filtration from California; claims use of quantum/superconducting technology; partially designed by John Curl. Zero Impedance - Add-on devices such as toroidal autoformer that have the ability to multiply a speakers impedance by 2x, 3x, or 4x. TWD Acoustic Products Ltd - Produce acoustic products and wireless projects for headphones. Taiwan Carol Electronics Co. Ltd. - Taiwan. Manufactures a range of dynamic and multimedia microphones, such as wireless, supercardiode, reciting, CB, cable, mega phone, as well as speakers and power amps. Hanics - Manufacturer for multimedia accessories including micro speaker and receiver, microphones, and hands free earphones. O. W. Donald Co. - Manufacturer of mobile TV antenna, audio and video cables, noise filters, and repeaters Klippel GmbH - German company specializing in measurement and control technology for loudspeaker measurement for speaker manufacturers. Nitty Gritty - Makes vinyl cleaning systems and accessories. Jitter - German manufacturers of universal jitter attenuation device. Provides also information about jitter. Michael Green Audio - Sound specialist and designer of speakers’ furniture and accessories. Provides discussion forum and industry news and reviews. Zon Audio - Manufacturers of audio distribution devices such as multi-source, multi-zone inputs and outputs sound distributors. Ichikawa Jewel - Manufacturer of XLR and RCA connector, tonearm, cables and accessories. Japan. ViaBlue - Manufacturer of cables, plugs, spikes and accessories. Germany. Music Works - Design and supply power leads, blocks and tables for hi-fi music systems and home cinema equipment. UK. Puretone - Manufacturer of hearing aids and assistive listening devices. EN46002 Medical Devices Directorate. Milty - Makes sound isolation, connectors and cleaning solutions. UK. Vivid Audio - Makes and design gold, silver and cotton audio cables. Warren Gregoire and Associates - Manufacturer of amateur radio headsets, desk microphones and push to and push to talks and also PC headsets for personal computers. Canada. Digital Recordings - The company does advanced research and development in acoustics and provides high-tech audio solutions for individuals and industry. Lists products, services, publications, opinions, links and contact details, plus Sound Off magazine. IsoTek Systems - Makes power conditioners, connectors, cables and plugs. UK. Oyaide - Makes power supply, cables, interconnects, plugs, power cord, and in-wall plate. Japan. Rainbow Arrival Science Technology - Makes multiroom equipment, infrared transmission and volume controls devices such as hub, and remote controls. Taiwan. Golden Sound - Manufacturer of acoustic discs, banana plugs, cones, squares, pads and cables. USA. Oriton - Manufacturer of carbon fibre audio support system. UK. Tenqa - Makes Bluetooth wireless stereo audio headphones and speakers. Fujikon Industrial Company Limited - Manufacturer of headsets, microphones and other audio components. Organic Acoustics - Manufacturer of organic acoustic panel