The cartridge of a record player outputs what's known as a phono signal, which is usually too weak for the standard audio inputs of power amplifiers, mixers, active speakers and other audio gear. Most of the time, these bits of kit require a line-level input signal. Line signals are much stronger (so louder) than phono signals, which is why you'll need a phono preamp to boost the signal when you want to hook your record player up to something like amp that takes line signal input only.
You Don't Always Need a Phono Preamp
In some cases, the gear you want to connect to your record player or DJ turntable features a phono input. In that case, you won't be needing any external phono preamp since one has been integrated in the device itself. In fact, most DJ mixers feature both line and phono inputs. If you can't find a phono input fitted to the device you want to connect, you'll definitely need a phono preamp.
Check the Inputs and Outputs of Your Record Player/Turntable
Modern record players often feature a built-in preamp, but not always. To check if your unit has one, see if there's a line or phono input round the back. If there's an input that says 'line/phono', you can most likely toggle between both options using a dedicated switch. If there's no mention of 'phono' anywhere, check the user manual that came with your record player. If you can't find any info in it, you're most likely looking at a phono output. That means you'll need a phono preamp to connect your record player to external gear.
What's the RIAA Curve?
The RIAA standard dictates how a vinyl record needs to be recorded and played back. Set by the Recording Industry Association of America (RIAA), this industry standard ensures maximum efficiency in terms of playback time without sacrificing sound quality. Since lower frequencies require more physical space than high frequencies, the RIAA standard cuts the lows by 20dB while boosting the highs by the same amount before the vinyl record is cut. For correctly played back sound, a phono preamp will need to reverse these 'unnatural' equalisation adjustments, boosting the lows by 20dB again while damping the highs by 20dB. This is called RIAA filtering, and what's great about it is that also reduces any noise in the process, simply because noise mostly rears its ugly head in the higher frequency range, which is precisely the range that's cut by the filter. Lastly, it's worth mentioning that it's the type of cartridge that will determine the volume of your record player or turntable.
MC & MM Cartridges: What's the Difference?
Magnetic cartridges can be roughly divided into two industry-standard categories: Moving Coil and Moving Magnet cartridges. Moving Magnet cartridges can be found in any price range, Moving Coil models are typically reserved for higher-end record players. One of the differences between both types of cartridge is the output voltage. Since MC cartridges have a lower output than MM cartridges, extra amplification is required. This in turn requires a compatible receiver or preamp input, which explains why some phono preamps feature a special MM/MC cartridge toggle switch.
Phono Preamps: What Else Do You Need To Know?
Many preamps offer an earthed connection. Record players can have different earth connections. In some cases, it's integrated into the signal cable, while other record players may feature a separately forked earthing wire that can be hooked up to the earthed connection of the amplifier to counter noise, hum and ground loops. Then there's the electrical resistance (impedance) of your MC or MM cartridge. This impedance rating needs to match the type of connection of your receiver or amplifier. Moving Coil cartridges have an extremely low impedance (typically 100 Ohms), while Moving Magnets are set to 47,000 Ohms. Most amplifiers are set to 47,000 Ohms as well, allowing you to simply hook up most record players without any issues. If you're not sure whether a cartridge is compatible or not, consult the user manual or the manufacturer's website. Certain high-end preamps also give you the option to adjust the resistance.
Frequently Asked Questions About Phono Preamps
Do I need a phono preamp?
Not every record player needs an external phono preamp. Take a look at the outputs of your record player and the inputs of the gear you'd like to hook up. If the external device doesn't have a phono input and your record player lacks a line output, you're going to need a phono preamp. See our Phono Preamp Buyer's Guide for more help and info.
What's a good phono preamp for my record player?
A good phono preamp is equipped with a RIAA filter and supports an earthed connection to your record player or turntable. There are also high-end preamps that specifically support Moving Coil cartridges and may or may not offer the option to adjust the electrical resistance (the impedance).
Which phono preamp should I go for?
Most more affordable record players are equipped with a Moving magnet cartridge. These units can be connected to any standard preamp. Got a higher-end record player loaded with a Moving Coil cartridge? In that case, you'll need an amplifier or receiver fitted with a special input for MC cartridges.
