Phono Preamps 101: The Only Guide You Will Ever Need!

Have you ever been in a situation where you purchased a new turntable setup and were excited to play your favorite record, but as soon as you plugged it in and played the vinyl, you were surprised to find it produced a dull musical output.

Don’t worry, you have not purchased the faulty turntable. The reason for this could be the phono equalizer. The vinyl turntable is a complex hi-fi system so one needs to understand about pieces of equipment that are required to set up the whole system. One such add-on is phono preamp also known as phono stage or phono equalizer.

What are Phono Preamps?

The preamp is a box-like device that contains complex switches of transistors or tubes. They serve two purposes:

1. Amplification: 

As we know, music from vinyl is produced in the form of vibrations captured from the record’s grooves. The cartridge converts these vibrations into electrical signals. But these signals are so weak at about 1-4mV if played on speakers, they will produce a thin and quiet sound.

The electrical signals from the cartridge are amplified to a level of 100-300mV using a phono preamp to make it suitable at a level for AUX input on your speakers.

It boosts weak electrical signals up to an extent so that it can fed into your stereo using AUX cables to convert into an audible sound. 

2. Equalization: 

During the cutting process of the vinyl in the manufacturing plant, the bass frequencies are minimized and high frequencies are strengthened which keeps groove dimensions small and narrow to increase the playback time.

The phono stage applies the equalization curve to scale the high frequencies and amplify the lower ones based on the RIAA equalization curve.

So the phono preamp helps to bring the frequencies back to the level of the master recording and you get the same sound quality comparable to the level of the original studio recording of the album.

The pre-amplifiers perform these functions to boost the overall sound quality and give you a warm music experience just like recorded in the studio.

Do I need one for my turntable?

The answer is YES!. It is a essential component of any vinyl stereo system. They are not needed only in two cases:

1. If your turntable has a built-in phono equalizer so there is no need for an external preamp to amplify electric signals coming from the cartridge, you can directly connect it to the stereos and play your record, or
2. If your turntable does not have one but the receiver you are using has a built-in phono preamp then you can connect your turntable with the receiver to amplify weak electric signals, which is then connected to hi-fi stereo to produce actual sound.

If preamp is not present on both the turntable and receiver then it is necessarily required. But the most modern turntables come with a built-in phono preamp, if you are a casual listener then it is more than sufficient to get the desired output of sound.

How to choose a preamp?

Choosing the right phono equalizer depends on the type of cartridge of the turntable. There are two types of cartridges available in the market, Moving magnet and moving coil.

So, they come with two specifications based on the type of cartridge. If your turntable has a moving magnet cartridge then choose a preamp compatible with it, otherwise go for the one that works fine with a moving coil.

There are also some phono stages available that are compatible with both types of cartridges with a switch to adjust depending on need.

When do you need an external phono preamp?

The external preamp is needed if your turntable as well as receiver does not have built-in phono preamps. So they are required to amplify the weak electric vibrations received from the stylus while tracking the grooves of the record. 

While some turntables come with built-in preamps, serious audiophiles often opt for external units. These standalone phono stages delivers superior sound quality, enhancing your vinyl listening experience.

If you’re looking to upgrade your hi-fi system, investing in a quality external phono equalizer can make a world of difference. It can transform your vinyl playback, offering a pure, immersive musical experience that truly showcases the depth and warmth of analog sound.

How do you connect a preamp to other devices?

Connecting is not a tedious task, you only need audio RCA cables to connect different devices. It is a cable with two wires, white and red which act as a bridge between the equipment’s of the audio setup.

It is always advisable to use good quality RCA cables because a good quality setup may produce bad music if poor quality cables are used.

1. Built-in Preamp

For turntables with built-in phono stage, first, you need to check at the back, you will find the switch to select “Phono” and “Line”, so slide the knob to “Line” mode. Now, the amplified signal coming out of the turntable can be directly connected to the powered stereos using RCA cables to get the desired output of the vinyl musical wonder.

For a built-in preamp receivers, connect the turntable to the phono input RCA jacks of the receiver using an RCA cable. 

2. External Preamp

Step 1: Connect the turntable using an RCA cable at one end to the input of the preamp on the other. 

Step 2: Take a separate pair of RCA cables and plug one end into the Output RCA jacks on the rear of the phono preamp and the other into the input of the receiver. Do not plug the cables into phono cables otherwise, you will get a distorted loud sound.

Step 3: Set your phono preamp to the proper cartridge setting, which is either MM (Moving Magnet) or MC (Moving Coil).

Step 4: Turn on the turntable and check the audio.

Final Thoughts

We have discussed how a phono pre-amplifiers converts low-voltage signals into high-voltage signals to get the desired sound quality from the speakers. 

These are an essential part of any analog audio system. It also plays an important role in sound equalization which is deliberately reduced during the cutting process to prevent wear and tear on vinyl records.

Built-in preamps serve the purpose of casual listening but if you are a serious music lover then an external phono preamp is an essential tool for your audio system.