More and more people are getting into vinyl and buying turntables, but to get the best sound you need to buy a separate "phono preamp." Some entry-level turntables come with built-in preamps, and that's a great way to get started, but if you want to really bask in all-analog glory you'll need to step up to a separate phono preamp. Look around on Amazon and you'll see a vast range of models, and some are decent enough, but they're not going to sound as good as a high-end phono preamp.
The thing to understand about phono preamps is the magnitude of their job. They have to amplify the miniscule signal output of a phono cartridge, which is just a few thousandths of a volt, and take it up to a volt or so without adding noise or distortion. Equalization is also part of the preamp's job, and that has to be handled with extreme care. Jim Hagerman's battery-powered Bugle phono preamp has garnered a strong reputation among budget-minded audiophiles, and it sells for $99 as a kit, or $149 assembled. Hagerman Technology products are handcrafted in the U.S. and come with a 10-year warranty and a 30-day trial period, with a 10 percent restocking fee. Shipping is free.
Hagerman has a Kickstarter project under way for another phono preamp, the AC-powered Bugle2, and if Hagerman reaches his Kickstarter goal the Bugle2 will sell for $99 for the kit, and $150 assembled and tested. It will work with both kinds of phono cartridges (moving-magnet or moving-coil). Hagerman has been designing phono preamps for more than a decade, and his products have been well received by audiophiles. If you know how to solder, building the Bugle2 kit should take an hour or so, but if you have trouble Hagerman can provide assistance via e-mail. The Bugle2 circuit board will be housed in a clear plastic case.
The prices listed here for the Bugle2 are for Kickstarter backers; the regular prices will probably be slightly higher.