How To Determine The Maximum Phono Cartridge Output

Are you struggling to figure out the maximum output of your phono cartridge?

Do you find yourself lost in technical jargon and unsure of how to make sense of it all?

Look no further!

In this article, we’ll break down the basics of phono cartridge output and help you determine the maximum output for your specific setup.

From understanding the difference between low-output and high-output MC cartridges to knowing how to calculate overload at the input, we’ve got you covered.

So sit back, relax, and let’s dive into the world of phono cartridges.

How To Determine Maximum Phono Cartridge Output

When it comes to determining the maximum output of your phono cartridge, there are a few key factors to consider.

Firstly, it’s important to understand that cartridges are typically rated by how much output voltage they generate when using certain standard test records. This rating is usually given in millivolts (mV) and is based on a specific frequency and velocity.

For example, if a cartridge is specified as 0.5mV (at 1kHz, 5cm/s), this means that it generates 0.5 millivolts of output voltage when playing a test record with a frequency of 1kHz and a velocity of 5cm/s.

However, it’s important to note that this rating is not necessarily the average level at an average volume. Instead, it represents the maximum output voltage that the cartridge can generate under ideal conditions.

To determine the maximum output of your phono cartridge, you’ll need to take into account the overload at the input and the equalization in the treble region. Typically, you should aim for a 20dB overload at the input. This means that if your cartridge is specified as 0.5mV, you should expect 5mV peaks.

Additionally, keep in mind that there’s another 20dB in the treble region due to equalization. This means that you’re getting close to 50mV at high frequencies. To prevent overloading of the second stage, it’s recommended to put the low-frequency turnovers first in a phonostage and pull down high frequencies as much as possible early on.

It’s also important to understand the difference between low-output and high-output MC cartridges. A high-output MC cartridge is meant to act like an MM cartridge as far as your phono stage is concerned. They tend toward a lower output voltage than most MMs but maintain compatibility with an MM phono preamplifier.

What Is Phono Cartridge Output And Why Is It Important?

The phono cartridge output is the electrical signal generated by the cartridge when the stylus and cantilever move within the record groove. This signal is then amplified and reproduced by the music system. The output voltage of a cartridge is typically measured in millivolts (mV) and depends on the strength of the magnetic field and the number of turns of copper wire in the coils.

Understanding the phono cartridge output is important because it determines how much gain, measured in dB, is needed from the phono preamp or step-up transformer. Moving magnet (MM) cartridges usually have output levels in the 3-6 mV range, while moving coil (MC) cartridges usually have lower output levels of less than 1.0 mV. This means that MC cartridges generally require more gain from the phono preamp, typically around 60dB, compared to MM cartridges which usually require around 35-40 dB of gain.

It’s also important to consider the loading of the cartridge, which refers to applying load resistors across the + and – leads on a MC cartridge. The correct load resistor value can be complicated to determine, but it’s important to avoid hindering compliance or lowering output voltage too much as this can stifle dynamics and high frequency response.

Types Of Phono Cartridges: Low-Output MC Vs High-Output MC

When it comes to MC cartridges, there are two main types to consider: low-output and high-output.

Low-output MC cartridges have fewer turns in the coil wire, which results in less internal inductance and impedance. This allows for more control over mating the cartridge with your phono amp or step-up transformer. Low-output MCs also offer the ability to determine by ear the best settings for your cartridge and system, as opposed to the standardized 47k ohm load for high-output cartridges. Manufacturers typically offer a range of loading values, usually ranging from 100-1000 ohms. However, in order to get the best performance out of a low-output MC cartridge, you’ll need a phonostage with higher gain, which can be expensive.

On the other hand, high-output MC cartridges achieve their increased output by including more turns of wire in the coil. This results in a higher voltage output and allows for more wire attached to the cantilever to increase inertia. However, for superior performance, you’ll need to properly track the high frequencies, which change the direction of the needle thousands of times per second. This may require a more sensitive phono preamp to fully tap into its potential. Additionally, high-output MC cartridges tend to be more expensive than low-output MCs.

In most cases, lower output MM cartridges are more favorable as they require fewer turns of wire and are generally considered to give a more consistent sound quality. They’re also likely to be cheaper and easier to work with. However, if you’re looking for the absolute best performance and are willing to invest in a higher-gain phonostage and potentially more expensive cartridge, a high-output MC may be worth considering. Ultimately, it comes down to personal preference and budget.

Understanding Overload At The Input: Calculating Maximum Output

To calculate the maximum output of your phono cartridge, you need to understand the concept of overload at the input. The overload at the input refers to the maximum input level that your phono stage can handle without distorting the signal.

To achieve a 20dB overload at the input, you need to ensure that your cartridge’s output voltage is 10 times higher than its specified rating. For example, if your cartridge is rated at 0.5mV, you should aim for 5mV peaks.

It’s also important to keep in mind the equalization in the treble region, which adds another 20dB. This means that you’re getting close to 50mV at high frequencies, so it’s crucial to pull down high frequencies as much as possible early on in your phonostage to prevent overloading of the second stage.

When choosing a phono preamp, it’s essential to consider its gain and headroom capabilities. The gain refers to the amplification factor of the preamp, while headroom refers to the maximum input level that it can handle without distorting the signal.

For example, if your cartridge has an output voltage of 3.5mV and you want to achieve a 20dB overload at the input, you only need 38.5dB of gain. However, if you want to ensure that you have enough headroom, you might want to aim for a gain of 41dB or higher.

Factors That Affect Maximum Phono Cartridge Output

There are several factors that can affect the maximum output of your phono cartridge.

Firstly, the type of cartridge you have can make a significant difference. Moving magnet (MM) cartridges typically have higher output levels than moving coil (MC) cartridges. This is because MM cartridges have a larger magnet, which generates a stronger signal.

On the other hand, MC cartridges have lower output levels but are known for their superior sound quality due to their lower moving mass. However, high-output MC cartridges can be a good compromise between the two, as they offer better sound quality than MM cartridges while still maintaining compatibility with MM phono preamplifiers.

Another factor to consider is the loading impedance of your phono preamplifier. Most phono preamps are designed to work with a specific range of cartridge loading values, typically around 47k ohms of impedance. If your cartridge is not properly loaded, it may not be able to generate its maximum output voltage.

Additionally, the number of turns in the coil wire can also affect the maximum output voltage of your cartridge. MC cartridges with more turns in the coil wire will generally have higher output levels, but this also means they will have more moving mass and may be more difficult to work with.

Finally, keep in mind that the maximum output voltage of your cartridge will also depend on the quality and sensitivity of your phono preamplifier. A high-quality preamp with good gain and low noise levels will be able to extract more from your cartridge than a lower-quality one.

How To Adjust Phono Cartridge Output For Optimal Performance

To adjust the output of your phono cartridge for optimal performance, you’ll need to start by setting the vertical tracking force (VTF). This is the force that keeps the stylus in constant contact with the vinyl and aligns the cantilever, stylus, and generator for correct operation. The recommended range for VTF is typically between 1.5g – 2.2g, but it’s important not to exceed this range as excessive VTF can overload the suspension and distort the cantilever, resulting in incorrect Vertical Tracking Angle.

Once you’ve set the VTF, you can fine-tune the output by adjusting the bias (sideways force) to compensate for the inward pull of the record groove. The cartridge manufacturer will recommend a suitable range of downforce, usually between 1.5 and 2.5g, with a specific weight listed as most suitable. It’s best to stay within this range, but if you want to experiment with different weights, be sure to stay within a safe range to avoid damaging your vinyl.

If your cartridge is a Moving Coil (MC) type, you may need to use a preamplifier or step-up transformer to boost the output voltage. This is because MC cartridges typically have fewer turns of wire than Moving Magnet (MM) cartridges, resulting in lower output voltage.

To get the most accurate and consistent results when adjusting your phono cartridge output, it’s recommended to use an electronic digital stylus force gauge. This will allow you to measure the force at the same level as the resting point of the stylus on the vinyl for greater accuracy. However, for modest systems, using a manual balance beam scale or arms calibrated VTF dial may be adequate.

Conclusion: Getting The Most Out Of Your Phono Cartridge

To get the most out of your phono cartridge, it’s crucial to match it properly with your phono stage. Make sure that the output voltage of your cartridge does not exceed the maximum input level of your phono stage.

Additionally, understanding the differences between low-output and high-output MC cartridges can help you achieve the desired sound quality. A high-output MC cartridge can offer a happy middle ground between a low-output MC and an MM cartridge.

Finally, keep in mind that the maximum output rating of your cartridge is not necessarily the average level at an average volume. Aim for a 20dB overload at the input and take into account the equalization in the treble region to prevent overloading of the second stage.

By considering these factors and properly matching your phono cartridge with your phono stage, you can achieve hi-fidelity greatness from your records and get the most out of your investment.