Synthesizer

Style Disk Warehouse - Style disks for Technics and Yamaha keyboards and organs, with free download samples available.
http://www.stylediskwarehouse.com

The MIDI Store - Sell music software, and new and used MIDI and audio equipment. Includes available product listings, gift certificates, product support, policies and contact information.
http://www.midi-store.com/

audioMIDI.com - California-based company selling computer-based music hardware and software with detailed product and supplier information. Also includes industry news, FAQ, links page, and specials.
http://www.audiomidi.com/

Stylophone Sales Corner - UK retailer of the 70s Stylophone synthesizer. Includes buying tips, products available and contact information.
http://www.stylophone-sales.fsnet.co.uk/

Analogue Modular Systems, Inc. - Seller of vintage analog synthesizers. Includes online auction, client list, typical stock list, manuals and accessories, interviews and gallery.
http://www.analogsynths.com/

A&C Hamilton - UK-based seller of new and used synthesizers. Includes available stock, tuition, events and contact information.
http://achamilton.co.uk/

Helpful Music - Information on the theory and practice of analogue synths. Includes author profile, news, basic concepts, purchasing tips, and video training product.
http://www.helpfulmusic.com/

Nova Musik - Digital and analog new and used gear
http://www.novamusik.com/

QChord Network - Sells the QChord - a "digital songcard guitar" made by Suzuki; also accessories, books and song cartridges. Based in Tarzana, California.
http://www.qchord.net/

The Synthesiser Service Centre - London, UK-based company that services, repairs, restores, designs and sells analogue and digital keyboards, modules, effects units and other musical devices.
http://www.synthservice.com

Musicians-Gear Online Shop - Offers "low priced" musicians-gear. Located in Germany, all prices are in German Marks (DM).
http://musicians-gear.com/

Big City Music - Source for vintage synthesizers. Includes item search, catalog of products available, downloads, photos and contact information.
http://www.bigcitymusic.com/

Sphere - Includes a products database, buying and selling information, services, news, resellers, company profile and contact details.
http://www.spheremusic.com

Rogue Music - New and used musical equipment, software and manuals. Primarily keyboards and pro audio. Separate auction site.
http://www.roguemusic.com/