Our guitar amplifier certainly does not sound the same it did in first months of use. With the passage of time, some sound characteristics become opaque. When you bought your tube amplifier, you were probably shocked by its sound, it had a touch, a resonance, a clarity, and a magnificent tone. But as time passed, you probably felt that your amplifier has sadly lost its ¨Mojo¨. So does it sounds a bit flat or thin or it just simply never sounds like it did before? The simple solution to your problem would be to change the amplifier’s valves on a regular basis. If you want to keep the sound in the best possible way and restore that sweet, organic tone, then that is the only way to go.
How to Tell If You Need to Change the Amplifier’s Valves?
One or more of the following signs may indicate that you may need to change the amplifier tubes.
- The lack of equipment power.
- Tonal change.
- Soft noises or whistles.
- Irrigating of irregular chirps.
It is important to know that tubes usually do not fail but they simply become weaker and weaker as time goes by. The problem is that, with the use and practice, sometimes you can barely notice the difference until of course, you change them.
The actual age of the tube is not so important, but how much they have been put to use. If you play your amplifier regularly and have spent a year or more of regular use, it is almost certain that it is time to satisfy yourself with a new set of tubes.
You Will Be Surprised by the Difference from the First Tone
There is a simple exercise to recognize if your valves are not 100% well. If you notice a loss in bass and power, it is very likely that your power tubes (also known as outlet valves) need to be replaced. Here you have a simple exercise to test the wear of the valves:
First, increase the volume of the gain section and slowly lower the main volume. If the noises continue after you have lowered the master volume, it is most likely a power valve. If you lower the main volume and the noises disappear, it is most likely a preamp valve (also known as an inlet valve).
If you want to change the amplifier’s tubes, it is always advisable to change the whole set.
How Long Do the Amplifiers Last?
That is a really tough question to answer. It mostly depends on how you play and how often. The speed at which a tube wears out is determined by the number of hours it has been turned on and the power with which it has been touched. There is also a mechanical component. If the amplifier has been hit hard, the valves will not last as long and will have to be changed more frequently.
Why Change the Rectifier Tube on Your Amplifier?
Many vintage amplifiers such as Vox AC30, Fender Twin Reverb, Vibrolux, and some Marshall use a rectifier valve. Other amplifiers use modern silicon diodes. The rectifier valve (or diode) is a key part of the power supply of the amplifier. Your job is to “convert” or rectify the AC to DC voltage, which the amplifier’s valves need. The output valves need a higher voltage (EL34, 5881 / 6L6, 6V6, EL84, etc.) and the voltage is usually reduced to be able to supply the small preamp valves (ECC83 / 12AX7, ECC82, ECC83).
If you plan to change the outlet tubes, it is a good idea to change the grinder as well, you can even keep the previous one as a spare.
Finally, after playing a long time, it is advisable not to move the amplifier until the valves have cooled completely. Valves are mechanically more susceptible to failure if the amplifier moves when it is hot.