As an entry-level vinyl record enthusiast, you believed that your turntable would have good amplification during playback with the use of a built-in amp. However, your audiophile friend suggested that you get a phono preamp, also known as a phono stage, to get better sound quality out of your audio system. When it comes to getting great sound, you trust his advice, but you’ve been wondering how a phono preamp will give you high-end sound. In this guide, we will look at some of these benefits and give you some things to look for in a new phono preamp.
Benefits of a Phono Preamp
Simply put, you can’t have a good audio experience without a phono preamplifier. When your LPs are playing, they are producing a very low sound that you can hear, even without the use of your speakers. This sound is very tinny and small, and you won’t hear it without close proximity and a quiet room. This sound, called the phono level sound, is the sound output that needs to be converted to electrical signals by the cartridge and stylus and amplified by the preamp to the line level, which is further amplified to the speakers.
Clearly, you simply can’t do without a phono preampamplifier since you need it to convert your analog vinyl player’s sound to the line level. Still, what are the benefits of an external phono preamp?
For many years, vinyl record player producers included the preamp within the bodies of their players. This stopped happening with as much frequency when other mediums came into being, like cassettes and CDs, but this actually improved the lives of vinyl lovers. When you can select the phono preamp stage as part of a record player/preamp duo, you’re able to better customize the sound quality of your overall system. For example, you can select a preamp that modulates frequencies in different ways so that your favorite genre of music has better musical fidelity.
External phono preamps should also closely match the quality of your audio setup; having an expensive vinyl player and a middling preamp will produce middling music. Additionally, the internal preamps included in many combo devices often don’t stand up in terms of quality, and additional component sound could equally cause distortion that will make it to your speakers. When you incorporate a preamp of sufficient quality, then your overall musical experience will be much stronger.
What to Look for in a Phono Preamp
When you’re on the market for a phono preamp, it’s critical that you seek out certain components and features. For example, if your audio system doesn’t have matching connections with your phono preamp, it means that you will have to purchase adaptors, which can further muddy the audio signal being sent down the chain. Here’s a look at what you should look for in a phono preamp.
Physical Dimensions
One of the first things you need to consider before making a purchase is the amount of physical space you have to add a new preamp to your audio system. A preamp can be quite large, especially if you get a tubular preamp. If you don’t have enough space for a full-fledged preamp for your record player, consider opting for a mini phono preamp that can easily stack with the rest of your audio gear.
Tube vs Solid State Preamp
With almost every new technology, especially when it comes to audio performance, there’s always an argument that pits analog vs digital. The same can easily be said about phono preamps because they tend to come in two varieties: tubular and solid-state. Let’s take a look at each:
Tube
This is the analog style of phono stage preamps. These are usually identified by vacuum tubes on the body that might even be comprised of glass. Within the bodies of a tube amp, you’ll find components like valves and transformers. When it comes to the overall design, tube preamps have a lot of similarities to guitar amps and have that same analog functionality.
It’s essential to understand that tube preamps sometimes need “burn in” time to reach their maximum sound quality. This is the time for the anodic films to form on the capacitors. This should take about two weeks of use to form.
When it comes to everyday use, it’s important to note that tube preamps are a bit more power-hungry than solid state preamps. They also tend to be much more fragile because there are more internal components, including glass vacuum tubes. Many audiophiles feel that these also produce warmer tones, but many counterarguments state that you can get this same warmness with higher-end solid state preamps.
A good example of a tube preamp is this Pro-ject Box S2. This tube box has replaceable vacuum tubes with discreet circuitry. It also welcomes most MM and MC cartridges.
Solid State Phono Preamps
It’s best to think of solid state preamps as circuit board amps because that’s what you’ll find under the surface. These are entirely digital preamps, and typically they are much more durable and have a tighter form factor when compared to tubular units. Equalization is done using software on the circuit board. While some consider these to have inferior sound quality, they also tend to be much more inexpensive options when compared to their counterparts.
One of the prime drawbacks of solid state amps is their tendency to pick up interference. Have you ever placed your smartphone too close to a speaker and heard a ticking, electronic feedback noise? Solid state preamps sometimes pick up this sound, which will hamper your listening experience.
Unlike tube preamps, which need to have their tubes replaced occasionally, solid state preamps last for years before you need to replace anything. Thanks to their inexpensive price points, you may prefer to replace the entire preamp rather than replace a failing component.
Type of Connections
When you take your first look at the phono preamp that you are looking to purchase, make sure that the connections that you need for things like your bookshelf speakers to connect to. Most of these devices will have at least one set of RCA inputs that you can use, but many also have a high-quality phono input that will provide more hi-fi sounds. XLR inputs and outputs are also important to be built into the device because they help keep noise to a minimum. These low noise inputs are typically found on high-quality phono stages.
If you plan to record your vinyls, you will need additional connection options on your phono stage. This will include things like a USB output slot to transfer the music to your computer easily. Make sure you check your devices to see what type of connectors you need because using an adapter to connect powered speakers is likely to cause sound quality issues during playback.
Also, you will want to make sure that there is a headphone jack on the phono preamp. Instead of using a headphone amplifier with a DAC (digital-to-analog) converter with your record player, you can plug your headphones into the phono amp, making it more convenient to listen to without turning on your entire speaker system.
Subsonic Filter
The low-frequency vibrations result from warped records can be blocked by a subsonic filter. These rumbles are not heard themselves, but they can distort other frequencies in the audio that you are listening to. Most phono preamps are designed with a switch that you can use to turn the filter on and off as you wish. These are typically found in the bass notes that you feel more than you hear, but having a switchable button will ensure that the bass notes have their intended sound when the stylus touches the vinyl.
Cartridge Compatibility
While record players have moving magnet (mm cartridges) and moving coil cartridges (mc cartridges), it’s important to know that many phono preamps are not compatible with moving coil cartridges. With that being said, there are phono preamps that can be used with both moving coil and moving magnet cartridges.
Most preamps that are compatible with both cartridge types have an impedance, gain, and capacitance setting that you can adjust. The Pro-Ject phono box S2 is a good example of a high-performance phono preamp compatible with both types of cartridges.
Learn more about moving magnet and moving coil cartridges in our Turntable Cartridge Types article. The bottom line is that you need to know which type of phono cartridge your tonearm uses so that you purchase a phono preamp that is compatible with the rest of your audio system.
Switchable EQ Curves
Before the 1950s, record player producers had a variety of equalization methodologies that included varied equalizations such as the Columbia-78, FFRR-78, and the Decca-US. Finally, in 1953, companies agreed that a standard equalization should be used. Full-industry adoption didn’t happen until the 1970s when the Recording Industry Association of America (RIAA) settled on a catch-all form of equalization called RIAA equalization.
For this reason, if you plan to play older records or records that were pressed overseas, you should select a preamp with switchable or selectable EQ curves. This will allow you to play these pressings as they were meant to be played using some of the aforementioned proprietary equalizations.
Phono Preamps Provide Quality Sonic Experiences
Whether you have a traditional wired setup or a newer Bluetooth speaker wireless configuration, you will need a phono preamp to deliver the intended sound quality of your vinyl records. In the end, purchasing one will only enhance your system’s overall sound profile, especially if you buy one with multiple equalization settings and the components to produce warmer, high-quality sounds.