Why do you need a phono stage aka a phono preamp? When records are cut the mastering engineer uses a drastic EQ curve (RIAA) to make it easier to etch the audio frequencies onto the vinyl master disc. A phono stage simply reverses this EQ curve so that you hear the audio the way it was intended. Connected to an amplifier without a preamp, the sound from a turntable would be barely audible and if you boosted the volume as much as possible it would sound tinny like your speakers are broken. This is because all the bass frequencies on the record have been severely cut and the high frequencies boosted. You need the phono preamp to boost the low end and cut the the high end in precise amounts. Only after this has been done can your amplifier do its job of powering your speakers and delivering the beautiful analog sound of vinyl.
While some turntables have a built-in phono stage, most don't; and while many amplifiers or powered speakers have a phono stage input, many do not or have low-grade inexpensive versions which limit the quality of music playback. This is why you might need an external option. To check if your amplifier or powered speakers have this essential preamp built in look for a dedicated input marked phono. Most portable speakers and many smaller modern home systems don'y have a phono stage input. If this is the case you can purchase a small external unit that does the job. You plug the output of your turntable into the phono stage input and then plug that output into a line level input (CD, Aux, etc.) on your amp or speakers.
A small investment in a great phono stage will help you get the most out of your record collection. The Pro-ject Tube Box is an audiophile grade phono stage with a dual-mono design. This means that one vacuum tube is dedicated to each channel for maximum channel separation and superior stereo imaging. It also has a subsonic filter to reduce super low-frequencies (below 20hz), including rumble from turntables, which can waste amplifier power and degrade the overall sound. The Tube Box offers a better signal to noise ratio than a standard preamp, as well as an extremely accurate RIAA curve, a beautifully wide soundstage, and an excellent control of the natural dynamics of music. Ultimately the end result is a more enjoyable experience of your music. It's worth noting that nearly all the Real Groovy staff who own turntables have a Tube Box in their setup. Take your system to the next level. Until Christmas or while supplies last, if you purchase any turntable in-store you can get the Pro-ject Tube Box for just $449 (RRP $649)!