www.thetubestore.com - Your online source for audio vacuum tubes.. Audio tubes for any amplifier: from high end home audio to classic guitar amps. If you aren''t sure about which valve you need, or what tubes you can substitute, let us help you. More electron tubes can be found in the tube store collection of New Old Stock (NOS) If you are looking for a tube shop carrying the very best tubes for your amplifier, you''ve come to the right place.