I am new to this and i have heard that after a while you have to change the tubes in a tube AMP. I wouldn't have a clue how to change them or where to purchase new tubes from, if i am rubbish at electrical DIY is it better to get a solid AMP or is the changing of tubes a simple process?
Thanks in advance!
Changing tubes is only a little less complicated than changing a light bulb.
They're plugged into a socket: pull them out, push them back in. The glass is much thicker than a light bulb so you are able to grab them by the glass without an issue. Because some of them are so old, though, the chances are greater of breaking off a pin. Many people recommend a slight "stirring" motion when you plug them in to equalize the force on the pins - sort of like torqueing opposite nuts when changing a tire. Most audio tubes have anywhere from 7 to 9 pins on the bottom. There's either a gap in the pins or a center post with a locating key, so it's impossible to plug them back in without being oriented correctly.
Now, the only caveat to that is that some tube amps may have the tubes enclosed inside the case, instead of on top or through large holes in the case lid. In those cases, you obviously have to take the case apart to get to the tubes. Amps built that way are few and far between, however, because everyone knows audiophiles like to "roll" tubes. That's the practice of changing out to different tubes to try and get an improved sound.
Tubes are very organic in nature and are not like opamps (solid-state devices) at all. Many of them were hand-assembled during parts of the manufacturing process. So, the tubes' sound varies from manufacturer to manufacturer. There were also many tube equivalents - slightly different tube types that will still work in a given amplifier design, but yield an even greater difference in sound. One tube might have more soundstage than another, or greater bass, better midrange, more detail or greater highs. These things are often subtle and not like applying equalization at all - more like the differences in different guitars or other musical instruments. Some tubes sell for $hundreds of dollars, simply because they offer some outstanding type of sound-flavor.
Tube vendors are all over the Internet and some even have storefronts with "Tone Consultants" (mainly for high-level guitarists and guitar amps). Tube Depot is one of those, but you may find many helpful hints on a tube vendor site: vacuumtubes.net, tubesandmore.com, vacuumtubesinc.com, esrc.com, etc., etc.
If you're willing to put up with the somewhat quirkiness of tubes, they can provide immense enjoyment and fun in the audiophile/headphone hobby.