It's no secret many an audiophile are fans of tubes, however they're hardly what anyone would classify as readily available-by that I mean you can't trundle down to your local drug store and buy a set. You won't even find them in your local big box electronics retailer. Imagine having to sit through a sales pitch from a "blue shirt" on tubes-that would be an experience.
All is not lost, for there is one place where tubes, like a lot of audiophile merchandise, are readily available-the Internet. For years I've relied on the Internet for all of my tube research and purchasing needs and have compiled a list a few favorites that I use on a regular basis.
TubeDepot is a great online resource for tubes ranging from the super cheap to the uber expensive. TubeDepot has a huge selection and rarely is anything out of stock, including many NOS (New Old Stock) or hard to find tubes. The site is updated regularly and while there isn't always a full description of what a particular tube may or may not sound like in certain systems, TubeDepot is still my go-to source for all things tubes. Oh, and their packing and shipping department is great and everything I've ordered over the years has arrived without incident.
Upscale Audio is more than just an online tube store; it's actually a full-fledged audio store selling many a high-end brand, which I'm sure many audiophiles already knew. Focusing on tubes, Upscale Audio and its proprietor, Kevin Deal, have the goods. Upscale's new site is a joy to use and navigate and the product descriptions are very useful, not to mention hilarious at times. Upscale Audio is also a great place to find some pretty rare tubes thanks in part to Kevin's hands-on approach to procuring tubes from all over the world. Lastly, if you're unsure as to which tube may be right for you and your system you can always give Upscale Audio a call and speak to a real, live, breathing human being.
The Tube Store, like TubeDepot, is an online tube warehouse, however unlike TubeDepot their site is a little wonky, by that I mean not as cleanly or as clearly laid out. Still, if you're looking for a vast selection of tubes on the cheap including bulk savings than The Tube Store is for you. The Tube Store does have a fairly respectable selection of NOS tubes though.
I recently learned of Tube Man through a fellow Audiogon member whom I purchased an amp from. He had sent me his remaining stock of tubes that went with the amp, most of which came from the Tube Man website. In an effort to learn about what I had received I went online and began searching. While the site isn't very organized (get your scrolling finger ready), Tube Man has a wide selection of both inexpensive and hard to find tubes, not to mention cryogenically treated and NOS varieties as well. The descriptions are minimal but tell you what you need to know and overall, with a little patients you'll find and/or get what you're looking for.