Valve guitar amplifiers have long captivated musicians with their distinctive warm tones, rich harmonics, and organic response. Central to their magic are the valves, also known as vacuum tubes, which play a crucial role in shaping the amp’s sound. If you’re an owner of a valve guitar amp, you may already be aware of the potential for tonal exploration through valve rolling. In this article, we delve into the exciting world of valve rolling, uncovering its benefits, considerations, and how it can elevate your amplifier’s sonic capabilities. I aimed to give you some ideas to experiment with tone.
Understanding the Fundamentals of Valve Rolling
What is valve rolling? Valve rolling refers to the practice of swapping out vacuum tubes, or valves, in a guitar amplifier to explore different tonal characteristics and sonic qualities. By replacing the preamp and power valves with alternatives, musicians can tailor the amplifier’s sound to their preferences without needing a tech to modify the amp.
Different types of valves and their sonic characteristics
Valves come in various types, including preamp valves (such as 12AX7, 12AT7, and 12AU7) and power valves (such as EL34, 6L6, and EL84). Each valve type has its own sonic qualities, influencing factors such as gain, headroom, breakup characteristics, and overall tonal balance.
Matching valve types to your amplifier and musical style
Consider your amplifier’s specifications, circuit design, and power rating when selecting compatible valves. Additionally, different valve types may suit specific musical genres better. For example, EL34 valves are often favoured for British rock tones, while 6L6 valves are associated with classic American clean sounds. Swapping out valves can significantly impact your amplifier’s sound. For instance, changing preamp valves can affect the amp’s gain structure, frequency response, and overall tonal characteristics. Power valves, on the other hand, influence factors like output volume, headroom, and the amp’s ability to deliver natural valve saturation.
Comparing popular valve brands and their unique sonic signatures
Various valve manufacturers offer distinct tonal characteristics. For example, some 12AX7 valves may provide a more pronounced midrange, while others might emphasize clarity or warmth. Research and experimentation with different brands can help you find the desired tonal qualities for your amp. The Tung Sol 12AX7 is an aggressive valve and excellent in Marshall amps. The JJ ECC83S is excellent for those chimy sounds of the 60’s.
Evaluating the influence of preamp and power valves on overall tone
Preamp valves contribute to the amp’s initial gain stages, affecting factors like compression, harmonic content, and response to picking dynamics. Power valves, conversely, have a more significant impact on output volume, overall headroom, and the amp’s ability to deliver natural valve saturation.
Achieving Your Desired Tone
Experimenting with valve combinations for diverse musical genres: Valve rolling offers an opportunity to explore various tonal possibilities. Experiment with different combinations of preamp and power valves to achieve specific sounds, such as sparkling cleans, smooth overdrives, or high-gain distortions.
Exploring the benefits of low and medium gain preamp valves: In addition to higher-gain options like the 12AX7, low and medium gain preamp valves, such as the 7025, offer distinct advantages. These valves are favoured by blues and jazz musicians for their ability to deliver a more gentle distortion characteristic, allowing for increased clean headroom and dynamic response. Other medium gain valves to consider are the Sovtek 12AX7WA and the JJ ECC83MG. The latter is brighter but has a spiral heater, and this makes it more immune to hum in amps with AC heater circuits. They can add clarity, warmth, and touch sensitivity to your tone. The 7025 is the secret to those lovely cleans and gentle overdrive of the classic Fender Blackface and Silverface amps. Modern Fender amps such as the Hot Rod Deluxe and Fender Blues Jr really shine when using the JJ ECC83MG or EH7025.
Some folks on various forums extol the virtues of using a 12AT7 ( ECC81) to replace an ECC83 ( 12AX7) . The objective is to have a lower gain valve and this is true when comparing these two types. BUT, the ECC81 type draws 10x the current and knocks off the biasing of the valve. This impacts the tone. The 5751 is also promoted as an alternative, and it is a lower gain valve. BUT, it has a different biasing voltage and so in some amps it will just plain not work. It is better to use 12AX7 compatible lower gain valves : 7025, 12AX7WA, ECC83MG.
Finding the right combination for your playing style: Experimenting with different combinations of low and medium gain preamp valves, such as the 7025, alongside power valves, can help you achieve the desired tonal characteristics for blues and jazz genres. This combination can enhance the responsiveness to your playing dynamics and deliver a more expressive, nuanced tone.
Low and medium gain preamp valves can contribute to increased clean headroom, allowing your amp to stay clear and articulate even at higher volume levels. This is particularly advantageous for jazz guitarists who require pristine, bell-like tones or blues guitarists who want a responsive and touch-sensitive platform for their expressive playing.
Setting the bias on output valves
To maximise the benefits of low and medium gain preamp valves, adjust the bias on the output valves. Setting them to 60% will give more headroom. Setting to 70% will have more breakup. This combination can help you achieve a harmonious balance between clean headroom and controlled power tube saturation, resulting in a sweet spot for blues and jazz guitar tones.
Enhancing Performance and Reliability
Balancing tonal improvements with valve longevity: It’s important to strike a balance between tonal enhancements and the lifespan of your valves. While some valves may offer exceptional tonal qualities, they may have a shorter lifespan or be more prone to microphonics. This is especially true for output valves when biased above 70% of full power. Many amp designers deliberately over run the output valves to seek out the ultimate rock tone. Consider factors like valve ratings, reliability, and your specific performance needs. We can give advice on this topic.
Evaluating valve lifespan and when to consider replacements: Valves degrade over time and usage. Keep an eye out for signs of diminished performance, such as increased noise, loss of output, or lack of clarity. When your valves reach the end of their lifespan or exhibit noticeable issues, it’s advisable to replace them to maintain optimal amp performance.
Proper handling, installation, and maintenance of valves: Valves are delicate components, and proper handling is essential to prevent damage. Avoid excessive heat, always handle them gently by their base, and ensure proper seating during installation. Regularly cleaning valve pins and keeping the amp well-ventilated can also contribute overall performance.
Navigating the Valve Market
Understanding valve ratings, grades, and NOS (New Old Stock) options: Familiarize yourself with valve ratings, such as gain factor, maximum plate voltage, and current draw, as they can influence the valve’s performance and compatibility with your amplifier. Additionally, explore the availability of New Old Stock (NOS) valves, which are vintage valves manufactured in previous decades and prized for their unique sonic characteristics.
Reliable sources for purchasing valves: Purchase valves from reputable dealers, both online and offline, who specialize in valve sales. Established sellers often provide accurate descriptions, reliable testing, and warranty options, ensuring that you receive genuine and quality valves. We are one of the leading sellers in the UK stocking a wide range of possibilities for you to try.
Recognising counterfeit valves and ensuring authenticity
Counterfeit valves can be prevalent in the market, so it’s crucial to be cautious. Fraudsters find the NOS counterfeit market very attractive due to high profits and minimal penalties compared to selling drugs. We have seen some very sophisticated fakery. Research reputable valve brands, check for trademarks, labels, and manufacturing codes, and purchase from trustworthy sources to minimize the risk of buying counterfeit or low-quality valves. Watch out for NOS valves in supposedly original boxes. Cardboard deteriorates over time and loses its “springiness” and usually smells musty. Nicely faded boxes with springy cardboard should make you wary.
Expert Tips and Tricks
Maximising the potential of your amplifier through valve rolling: Keep detailed records of valve combinations and their sonic characteristics to help refine your tone. Experiment with subtle changes, such as mixing valve types in different amp channels or adjusting bias settings, to explore further tonal possibilities.
Summarising the do’s and don’ts of valve swapping
Familiarise yourself with proper valve handling, installation, and safety precautions to prevent damage to your amplifier. Follow the manufacturer’s guidelines and, if necessary, consult experienced technicians or valve enthusiasts for guidance.
Seeking advice from experienced valve enthusiasts and technicians: Engage with online forums, communities, or local amp technicians who specialize in valve amplifiers. Sharing experiences and seeking advice from experienced individuals can provide valuable insights, recommendations, and troubleshooting tips.
Conclusion
Valve rolling presents an exciting opportunity for guitar amp owners to personalize their sound, fine-tune their tone, and explore new sonic horizons. By understanding the fundamentals, experimenting with various valve combinations, and carefully selecting valves that align with your desired tonal characteristics, you can unlock the full potential of your valve guitar amplifier. Remember to approach valve rolling with curiosity, patience, and an open ear to embark on a rewarding journey of sonic discovery. We are always happy to give us advice on the various types of valves. Feel free to email us info@valvetubeguitaramps.com
Why not now go have a look at our product range?
Disclaimer
While valve rolling can offer significant tonal enhancements, it’s essential to exercise caution, adhere to manufacturer guidelines, and consult professional technicians when necessary to avoid any potential risks or damage to your equipment.
Hi Stewart spoke to you recently, about my Rift amp, which is hand wired based on the Deluxe Reverb.I sent it back to Chris at Rift amps, to put a bit more gain on the non trem
channel , and he asked if I wanted reverb adding to it as well. I was trying to get this channel to sound like a Tone King Imperial. Recently it’s made a few pops and farts, and now it just seems to hiss all the time. Would you have time to revert this back, and check the valves?, could this be done in a day? .Thinking of coming to the coast for the day, with my family, and dropping the amp off with you cheers pal