How Long Do Rectifier Tubes Last?

How do you know if a vacuum tube is bad?

When a vacuum tube develops an air leak (a small crack or bad seal by a pin for example) this getter color will change to pure white.

If you see this you know with 100% certainty that the tube is bad.

Third, look for a purple glow that is very focused around specific elements inside the tube..

How does a rectifier tube work?

The rectifier tube is a one-way valve that combined with the power transformer acts as an electron pump to convert 325 volts RMS AC into 360 volts DC. This high voltage AC from the transformer is often called HT (high tension) voltage.

What happens when a rectifier tube goes bad?

Usually when the rectifier tube goes bad it will blow a fuse or exhibit low voltage output depending on how it fails. Sometimes with a dual element rectifier just one half will go south without shorting and this will be the low voltage condition.

How long do 12ax7 tubes last?

about 10,000 hoursSmall signal tubes like a 12AX7 or 6922 will work well on average for about 10,000 hours. If you leave your equipment on 24 hours a day, well you do the math: There are 8,760 hours in a year.

Do rectifier tubes affect sound?

So yes, a different rectifier tube type WILL affect tone. But if a tube is giving 350v, it’s 350v whether it’s a NOS tube or a chinese new production. All a rectifier tube does is rectify AC into DC. There’s no DC in your tone signal (tone signal is AC), so in that regard, no they do not effect tone.

What does a rectifier do in an amplifier?

The function of the Rectifier Tube in a guitar amplifier is to convert AC voltage from your power source to the DC current used in the internal operation of the amp’s circuitry.

Is it OK to touch vacuum tubes?

Think of a vacuum tube as a light bulb. It is a glass envelope that generates heat as it is working. You shouldn’t be handling them all the time but occasionally touching them will not hurt. Let it cool off first though, they can get mighty toasty.

Why is it called Dual Rectifier?

This term refers to the selectable solid-state/tube rectifier found on certain Mesa/Boogie amplifiers. Most modern tube amps use solid-state rectifiers to convert AC current to DC.

What is a rectifier used for?

A rectifier is a device that converts an oscillating two-directional alternating current (AC) into a single-directional direct current (DC). Rectifiers can take a wide variety of physical forms, from vacuum tube diodes and crystal radio receivers to modern silicon-based designs.

What is solid state rectifier?

The job of the rectifier is to convert AC waveforms into DC. This happens in a diode. A diode can be in a tube, or it can be a silicone (solid-state) diode. Solid-state rectifiers have no internal resistance, which for audio purposes results in a punchier, more articulate amp response than a tube rectifier.

Do tubes affect tone?

Sometimes a power tube may glow blue inside. It has no effect on the sound. This phenomenon only happens in a tube with better-than-average vacuum (pure). Therefore, the tube is actually a better-quality tube!

Do rectifier tubes wear out?

Do rectifier tubes normally wear out some (long) time after power tubes? Not unless it’s a NOS rectifier. They tend to last for decades. New production ones have been known to last from one day to about 2 years unless they’re very lightly used.

How do I know when my tubes need replacing?

A: These are the most common signs that tubes need replacement: Excessive noise (hiss, hum) including squealing or microphonic tubes. Loss of high end. … A muddy bottom end; Sounds like there is too much bass and note clarity is lost. Erratic changes in the overall volume. … The amp doesn’t work!

How often should preamp tubes be replaced?

You should replace them when they are dead. *There is no set rule for how long they last, but in general, they last longer than power tubes. *Maybe twice as long or better life expectancy for power tubes. *They are also self-biasing of course, so don’t be afraid to change them yourself.

How much does it cost to replace tubes in an amp?

EL84 aren’t much more. If you just get run of the mill stuff it will be cheap. Once you start looking into NOS tubes, etc, you can expect to pay $25-200 per tube in some cases.

What does a bad tube sound like?

Preamp Tubes. Preamp tubes usually cause problems through noise or microphonics. If noise, you will hear hiss, crackling, popping or similar issues. If you hear squeal, hum or feedback, it is typically a microphonic tube. Noise from microphonic tubes will typically increase with a volume increase.

Can bad preamp tubes cause volume loss?

Use the wooden part to tap each of the preamp tubes and main power tubes. A good tube will be a dead ‘thud’ sound, so if you hear one that has a high ringing rattling sound, that’s the bad tube. Bad tubes will make volume drop and tone sounds will be dulled. When a tube goes bad, this is exactly what happens.

Why do tubes sound better?

In contrast, vacuum tubes operate in the point of an overload without the addition of an unpleasant distortion. To wrap things up, tubes sound better because it is able to produce a musical, smooth, warm, loud, clear, subtle and seamless sound at high frequency because it affixes harmonic distortion.