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F&T Mersen Electrolytic Capacitors for Guitar Amps and AmpTechs

Why F&T Mersen Capacitors are the Top Choice for Amp Techs: A Breakdown of Quality and Reliability

Written by
Andy Johnson
Published on
April 20, 2023 at 4:05:53 PM PDT April 20, 2023 at 4:05:53 PM PDTth, April 20, 2023 at 4:05:53 PM PDT

Why F&T Mersen Capacitors are the Top Choice for Amp Techs: A Breakdown of Quality and Reliability

From the electricity in the wall, converted by your power supply and resonating in your output. F&T Mersen Capacitors are long lasting and devoted. And that’s why we use them.

Power supply filter capacitors operate in the heart of your equiptmnent’s power supply to smooth and condition it for trouble and noise free operation. F & T’s Mersen capacitors offer unparalleled reliability for this job and that’s why we use them.

Polarized aluminum electrolytic capacitors allow much higher capacitance voltage (CV) per unit volume than ceramic or film. In an era where other companies are in a “race to the bottom”  in terms of price point F & T has maintained excellence through quality. From higher resistance to voltage spikes, to continuing to manufacture size/value options that are needed in the industry, their no-exception attitude pairs well with our high build standards here at MojoTone. F& T capacitors don’t just test well, they perform in real world applications.

F&T Mersen’s Support in the United States

We’ve also found a huge amount of support in the USA by F&T for their capacitors which helps us when we have questions that need answering. You know as well as we do that electricity in a music environment can be rigorous, so we value the support and dedication that they provide stateside.

What is the Break in Period for F&T Mersen Electrolytic Capacitors?

Every new electrolytic capacitor has a burn in period. There’s a forming process during which the anodization layers on the electrodes reach full thickness and the electrolyte gets conditioned as well. 

A Breakdown: What Electrolytic Capacitors are Made Of

Let’s start with the outside; on the top and bottom of a capacitor are a set of metal plates which are the conductors that attract an electric charge. Moving inward you’ll find between the two plates an insulator or material that electricity is not attracted to. The insulator is commonly referred to as a dielectric and can be made of paper, glass, rubber, pleastic, etc. Connecting it all together are two electrical terminals that connect the conductors to the rest of a circuit. One end connects to power, and the other flows to the ground.

TL;DR: A capacitor is basically a rolled up sandwich of 2 conductors insulated from each other by some insulating material

A Brief History: Who Invented Capacitors?

English Chemist Michael Faraday (you may have heard of him) gets the credit for modern capacitors, but he wasn’t the first to invent. But his addition was critical in that he demonstrated the first practical examples of the capacitor and how to use it to store an electric charge in his experiments.

Also thanks to Faraday we have the capability to measure capacitance as it’s measured in Farads. Thanks dude 🤙 

But before Faraday some records point to the late German scientist (go figure given F&T’s German roots) Ewald Georg Von Kleist as having invented the first capacitor in 1745. Later on a Dutch professor Pieter Van Musschenbroek designed something similar, now known as the Leyden Jar. 

They’re both credited for their creations but Faraday made it all work through testing and measurements.

How it Works: Capacitors

Starting with a charge > Buildup > Charge Stored > Two plates release the charge

How do you Measure Charge in an Electrolytic Capacitor?

F&T Mersen uses uF for their measurements, which is the abbreviation for Microfarad. It’s written as 0.000001F

Using Electrolytic Capacitors in Guitar Amps


Naturally, all you really care about is how they work in guitar amps. So we’ll focus solely on series circuits. Here’s the nitty gritty:

When you use electrolytic capacitors in guitar amps you are mostly putting them into their power supplies. There are stages in such a power supply, and at each node there will be a voltage drop from the starting voltage. At the first or highest node there may be multiple capacitors in parallel to achieve the desired filtering of the power supply.  Each one of these nodes or filters forms a high pass filter, since the majority of the noise that must be removed from the power supply is down near 50 to 60hz, the frequency of the power coming out of your wall. So not only are the choices of power supply filter capacitors about overall capacity, there is also a formula that depends on the series resistance in the supply in conjunction with each stage's filtering that allows you to arrive at a suitable filter cutoff frequency.

Show us how you’re using your F&T Mersen Electrolytic Capacitors!