The tone will be much more saturated, although the tube life is significantly shortened. Under-biasing: If under-biased, tubes will run too hot.As a result, your tubes are colder and the tone is much “thinner.” However, your tubes will last longer this way. Over-biasing: If over-biased, there won’t be enough voltage to run the tubes properly.So we have three possible outcomes in this: With the right bias, your amp’s tubes will not only produce a better tone but will have a longer life. Ultimately, the proper bias will keep the tubes operating properly and at the desired temperature. It can either be a steady stream, a slow stream, or an unbearably strong stream. But in this guide, we’ll focus on those that require biasing.īias can roughly be described as running water through a tap. There are also some rare cases of power amps with self-biasing circuitry. In almost all cases, preamps in tube amps have self-biasing circuits. There’s absolutely no need to bias preamp tubes. One important thing to note here is that bias tweaking is only about tubes in power amp sections. Essentially, it keeps the right voltage being fed into the tubes. When it comes to tube-driven amps, it’s a process that makes sure that tubes are working at their optimum capacity. 2 How Often Should You Get Your Tube Amps Biased?įirst off, how would you define amp biasing? We’ve mentioned the DC voltage applied to an electrical component in a circuit where AC is also present.1.5 Can I Bias and Re-Bias My Amp By Myself?.1.4 How Much Does It Cost to Get Amps Biased?.1.3 Should I Do It Evert Time I Replace the Tubes?.However, in most cases, biasing should be anywhere between $25 and $100. The price differs depending on a few factors. A bit complicated, right? Well, I’ve said that it’s not the simplest question to answer. If we’re talking about vacuum tubes in a tube-driven amp, bias is a direct current voltage supplied to a tube that controls the flow of electrons within itself when there’s no guitar signal present. The idea is to establish proper conditions so that a specific component could operate normally. Electronic biasing refers to the direct current voltage applied to a terminal of an electric component in a circuit where alternating current is also present. Well, these aren’t exactly the simplest questions to answer. One of those maintenance procedures is biasing.īut what is amp biasing and how much does it cost to get amps biased? However, they not only come with a higher price but also require special care and maintenance.

Although the technology is pretty much archaic at this point, there’s a lot of favorable traits they bring. Even after all these years, a surprising amount of guitar players still prefers tube-driven amplifiers.

How to bias guitar amp tubes