If you’re an audiophile, you know that every little detail matters when it comes to sound quality.
That’s why measuring phono cable capacitance is an important step in optimizing your turntable setup.
But how do you do it?
In this article, we’ll explore different methods for measuring phono cable capacitance and provide some tips for getting the most accurate results.
Whether you’re a seasoned pro or just starting out, this guide will help you fine-tune your audio setup and get the best possible sound from your vinyl collection.
So let’s dive in!
How To Measure Phono Cable Capacitance
There are a few different methods for measuring phono cable capacitance, but the most common involves using a capacitance meter or a multimeter that can measure capacitance.
First, remove the cartridge from your turntable and clip one probe of the meter to the outer shield of the RCA connector, and the other to the center pin. Before taking any readings, record the initial reading on the meter as this will be the capacitance of the meter cables. Some meters can be zeroed out, so be sure to check your specific model’s instructions.
Make sure your meter is set to the lowest setting that is not in picofarads (pf). Typically, 10 on your meter will mean 100pf. However, it’s important to remember to add 100pf as this is usually the phono preamp’s internal loading, although this may vary depending on your specific setup.
It’s important to note that using an inexpensive multimeter for this method may not provide the most accurate results due to the capacitance range and resolution being too high. Typically, cables run around 20-30pF/foot, so you’ll be measuring in the very lowest part of the meter’s range.
Another method involves using a test record and measuring the frequency response after the preamp, adjusting the capacitance for a flat response. This measures after the RIAA compensation and all that jazz but can be easier to do with tools at hand.
If you don’t have access to a capacitance meter or multimeter, you can estimate the length in feet from cartridge to preamp and multiply by 25pF/ft for a rough idea. This is because tonearm wiring itself tends to have higher capacitance than interconnecting cables, and phono interconnects are often smaller and more flexible with higher capacitance.
Understanding Phono Cable Capacitance
Phono cable capacitance is an important factor to consider when setting up a vinyl system. The capacitance of a phono cable determines how much high-frequency information is lost or emphasized, and can greatly affect the overall sound quality of your system.
Phono cables are designed to handle low-level signals and have a very low capacitance rating, typically under 80 pF per meter. This is because the cable needs to be able to transmit the weak signal from the turntable’s tonearm to the phono preamp without adding any noise or distortion.
When choosing a phono cable, it’s important to consider the recommended load capacitance of your cartridge and the input capacitance of your phono preamp. The sum of these two values should be close to the recommended load capacitance of your cartridge in order to avoid over-emphasizing or under-emphasizing certain frequency ranges.
Measuring the capacitance of your phono cable can be done using a capacitance meter or multimeter, although it’s important to note that using an inexpensive multimeter may not provide the most accurate results. Another method involves using a test record and measuring the frequency response after the preamp, adjusting the capacitance for a flat response.
In general, it’s best to choose a phono cable with a low capacitance rating and to ensure that the total capacitance presented to your cartridge is within the recommended range. This will help ensure that you’re getting the best possible sound quality from your vinyl system.
The Importance Of Measuring Phono Cable Capacitance
The capacitance of interconnect cables plays a crucial role in the quality of reproduced sound, especially if you’re using long cables or have audio equipment sensitive to high capacitance. Measuring phono cable capacitance can help you determine the best cables for your setup and ensure optimal sound quality.
There are many different types of RCA cables available, ranging from generic to premium. Measuring the capacitance of these cables can help you determine which ones are best suited for your needs. For example, some generic RCA cables may have a capacitance of 300-600pF, which may be too high for some setups.
It’s also important to note that even DIY cables made from high-quality materials may not necessarily have low capacitance. For instance, a 1.5 feet RCA cable made from Canare GS-6 guitar cable and Rean RCA male plugs with gold contacts had a capacitance of over 140pF per meter, which was higher than some cheaper cables in the author’s possession.
Measuring phono cable capacitance can help you make informed decisions about which cables to use in your setup. It’s important to remember that while low capacitance is generally desirable, it’s not the only factor to consider when selecting interconnect cables. Other factors like shielding and resistance may also play a role in determining the overall sound quality of your system.
Equipment Needed For Measuring Phono Cable Capacitance
To measure phono cable capacitance, you will need either a capacitance meter or a multimeter that can measure capacitance. In addition, you will need test leads with clips near the end of the cable to take accurate readings.
It’s important to make sure there is no DC path to ground either through the cartridge coils or via a resistance network. This means that whether you measure the external interconnecting phono-to-preamp cables or the internal tonearm cables, the rule applies.
For measuring the internal arm cabling, use an ohm-meter (with the cartridge removed!) and make sure there is an open circuit from signal conductor to ground. Then use the capacitance meter to take accurate readings.
If you have access to an RLC meter or VNA, these are expensive options that can provide even more accurate results. However, they may not be necessary for most home setups.
Method 1: Using A Multimeter
One method for measuring phono cable capacitance is by using a multimeter that can measure capacitance. This method involves removing the cartridge from your turntable and clipping one probe of the meter to the outer shield of the RCA connector, and the other to the center pin.
Before taking any readings, it’s important to record the initial reading on the meter as this will be the capacitance of the meter cables. Some meters can be zeroed out, so be sure to check your specific model’s instructions.
Make sure your meter is set to the lowest setting that is not in picofarads (pf). Typically, 10 on your meter will mean 100pf. However, it’s important to remember to add 100pf as this is usually the phono preamp’s internal loading, although this may vary depending on your specific setup.
It’s worth noting that using an inexpensive multimeter for this method may not provide the most accurate results due to the capacitance range and resolution being too high. Typically, cables run around 20-30pF/foot, so you’ll be measuring in the very lowest part of the meter’s range.
Method 2: Using A Capacitance Meter
Method 2 involves using a capacitance meter for more accurate results. It’s important to use a genuine capacitance meter rather than a multimeter with a capacitance setting, as the measurements may not be precise enough for our purposes.
To begin, set your meter to C for capacitance. Push one of the cable’s plugs firmly against a wooden table and use the meter’s probes to touch both contacts of the same plug; one on the tip and the other on the sleeve. A proper cable should measure a capacitance value of 100pF per meter, meaning a 20cm long patch cable should give you a reading around 20pF. However, it’s important to note that capacitance values are frequency-dependent, and it’s recommended to use 1kHz for reliable readings.
Look for discrepancies between different cables and make sure that changes in capacity are in the correct relation to the cable’s length. If you’ve made your cables correctly, you will be able to guess fairly accurately a cable’s capacitance value after you’ve been measuring for a little while. You could also make notes of the capacitance values for your guitar cable and all the signal cables in your cable loom, which can later be compared with the measurements taken from your other cables.
Repeat the same tests for all of your signal leads, including all patch cables, your guitar lead, and all signal cables connected to your amp. There is no need to measure capacitance with AC-power cables. Resistance measurements, on the other hand, are very important. The resistance between the different conductors in an AC cord should always read infinite. Any other reading suggests a short circuit somewhere and should prompt serious investigation.
Tips For Accurate Measurement
To ensure the most accurate measurement of phono cable capacitance, there are a few tips to keep in mind. First, make sure to remove the cartridge from your turntable before taking any readings. This will prevent any interference or false readings from the cartridge itself.
Next, lay the test leads flat on a table or other surface and space them apart with clips near the end of the cable. Be sure to clip the leads to the cable without moving them, as any movement can affect the accuracy of your readings.
It’s also important to avoid holding the test leads with your fingers, as this can add too much capacitance and create highly variable results. Instead, use clips or other tools to keep the leads in place.
If you’re using an inexpensive multimeter for your measurements, keep in mind that the capacitance range and resolution may not be ideal for measuring cables. These meters are typically designed for checking larger capacitors and may not provide the most accurate results for measuring phono cables.
Finally, if you’re estimating the length of your phono cable to calculate capacitance, be sure to multiply by 25pF/ft for a rough estimate. This takes into account the higher capacitance of tonearm wiring and smaller phono interconnects.
By following these tips and using a reliable method for measuring phono cable capacitance, you can ensure that your audio setup is optimized for the best possible sound quality.
