Why does my record player sound so quiet compared to my other components?
Odds are you need a phono preamp. Older stereo receivers and amps are almost always equipped with jackets that are labeled “phono.” This means that phono preamps are installed therein. Record players send a quieter signal than do CD players, cassette decks, iPods docks, etc, and they therefore require additional amplification. Receivers and amps released during the 90s and later (when CDs became the primary medium of audio playback) commonly lack this feature, and necessitate an outboard phono preamp in order to use a record player with them. All record players demand a preamp at some point in the signal chain. If the preamp is not built into the receiver or into the record player itself, an outboard preamp will be necessary. How do I hook up a phono preamp?
Here are the basics:
turntable RCA cable output → phono preamp RCA input → phono preamp RCA output → stereo receiver RCA “AUX” input
So you’ll need a preamp and a spare set of RCA cables. Keep in mind that the “AUX” input on your receiver is the same as the “CD,” “Cassette,” and “Video” inputs. They’re all what’re called line-level inputs. A line-level signal is what the phono preamp’s output sends. When the signal leaves the preamp output, it’s basically the same as what a CD player or cassette deck would send, which is why any of those inputs on your receiver will work. How important is the quality of the preamp?
Quite. If you’ve got a good cartridge and turntable, a good preamp behind them is advisable. You’ll want something that boosts the phono signal in a clean and quiet manner. This way you’ll be getting the most from your entire rig. Generally speaking as you step up the line of available preamps, you’re paying for a lower noise floor. In terms of sonic performance, you’ll hear more of what’s in the record groove and with less extraneous noise. So how do I go about choosing a phono preamp?
Remember from above that there are two sorts of standard-mount cartridges, MM and MC. You can get preamps that are built solely for MM cartridges, solely for MC, or for both types. All MM cartridges have outputs of 2.5mV or greater, 4-5mV is typical. These are considered “high output” cartridges. There are also high output MC cartridges that normally kick out about 2.5mV of output. These can be used with MM phono preamps. However, most MC cartridges are “low output” cartridges. Their outputs generally range from .3-.8mV, and they require a phono preamp designed to accommodate that output level. Preamps that deal with both MM and MC cartridges either have separate inputs or have a switch that can be flipped to apply additional gain for use with low output models. Higher end preamps often have several gain and loading settings that allow you to optimally mate them to your cartridge based on output and electrical impedance. MC cartridges have recommended loading values set forth by their manufacturers. This information can be found on our site as well as in the literature that comes with the cartridge.
For low output MCs, a good rule-of-thumb is to have enough gain in the phono stage to amplify the cartridge output to 250mV. Here is a table of gain values that will do that.
Cartridge Output ...... Gain in dB
0.50mV ......................... 54dB
0.40mV ......................... 56dB
0.30mV ......................... 58dB
0.20mV ......................... 62dB
0.10mV ......................... 68dB
There are also solid-state and tube driven phono preamps, which further complicates your decision but also makes it more fun! Solid-state electronics tend to sound more clean and quiet, while tube gear is more warm, “musical,” and inviting. It’s just a matter of preference.