How to Find the Best Tubes for Marshall JCM 900

While it’s often been the subject of criticism, the Marshall JCM 900 has without a doubt cemented itself on Marshall's list of the all-time most iconic amps.

Even then, while cranking this amp up to blast your audience with some classic Metal and Rock tunes may be the best feeling ever, you’re going to have to replace the tubes at some point in time.

If you’re reading this, perhaps that time is now for you. No worries though. We’ve prepared a list of some of the best options to get you back to your grooving ways.

First off, let's go through what tubes the JCM 900 uses. The Marshall JCM 900 comes with three 12AX7 preamp tubes and four 6L6 or 5881 power tubes.

Now that we know what we’re looking for, let's dive into our guide for finding the best tubes for Marshall JCM 900.

Best Preamp Tubes (12AX7)

Finding the right preamp tubes can be tough. Check out some of the best options below.

1. Mullard 12Ax7/CV4004

Best Tubes For Marshall Jcm 900


  • Dual triode
  • Small plating structure to reduce noise
  • Long lifespan
  • Perfect for high gain

Mullard tubes are considered to be some of the best on the market. Originally, Mullard tubes weren’t only used for audio but also military gear. For this reason, they’ve since come to be known as some of the most durable.

Today, you can purchase Mullard reissue tubes that are manufactured in Britain. These tubes are particularly good for a vintage clean sound, and a huge part of their popularity is because of this.

The Mullard 12Ax7/CV4004 offers vibrant sounds for chords and high gain for solos, and it also gives an unexpected tight bass. It is well known for its pure tone and balance of frequencies. Mullards work well with high-wattage Marshall Amps like the JCM 900. However, one downside of Mullards is that they’re increasingly difficult to find and hence more expensive compared to other tubes.

2. Gold Lion 12Ax7/CV4004

Best Tubes For Marshall Jcm 900


  • Short plates to reduce noise
  • Dual triode
  • Gold-plated pins to prevent oxidization
  • Rugged thick glass for durability
  • Matched pair

The Genalex Gold Lion 12Ax7 tubes are one of the best modern tubes on the market. They have a very brilliant, full-sounding mid-range sound and well-balanced high and low sounds, which gives them an overall smooth and tight performance.

The CV4004 is designed with the same standards as the long plate ECC83 but with shorter plates to reduce noise. The control on the highs and mids is excellent and eliminates any grating high sounds and booming basses. They’re a bit pricey but are worth every single penny. They have high gains and low noise and are best for rock and high gain shredding.

3. Tung Sol 12Ax7/ ECC83

Best Tubes For Marshall Jcm 900


  • Dual triode
  • Gold pins version and standard pin version
  • Matched pair for gold and matched quad for standard

The Tung Sol 12Ax7 tubes are a favorite when looking for high gain tubes, and they give a very warm sound rich in harmonics. This kind of tube is good if you play blues and jazz. They have low micro phonics and low noise, which makes the work great in any position in your amp.

These tubes are described to have a dynamic 3D sound, meaning round open and clean. They’re best for high-gain rock and line stage amps rather than photo stages where low noises are required.

4. Svetlana 12Ax7

Best Tubes For Marshall Jcm 900


  • Dual triode
  • Balanced lows, mids, and highs
  • Large plate design for full-body sound
  • Matched pair and trio

If you’re on a budget, then the best tube to go for would be the Svetlana. It has everything you want in a preamp tube, from negligible noise to no microphonic issues and a very clear refined sound that’s not too bright. It has less gain compared to the Tung Sol and is good for rhythm and lead playing.

Best Power Tubes (6l6/5881)

If you're in search of new power tubes, look no further. Let's go over some of the best options on the market.

1. Tung-Sol 6L6


  • STR beam-power tetrode tube
  • Long-lasting
  • Smooth overdrive
  • Max plate Watts - 30 W (Tung sol 6L6)
  • Max plate Watts - 25 W (Tung sol 5881)

The Tung sol 5881 gives the same sound quality as a NOS tube at half the price. It delivers classic deep lows and crystal-clear highs as well as a full mid-range. It also handles biasing very well.

The Tung Sol 6L6GC-STR is one of the best all-around power amps. This is a reissue that’s similar to the 1960s version. They have a rugged shape, which makes them sturdy and highly durable. It’s really good for a smooth overdrive, and it has a higher output setting than the 5881. It comes in soft, medium, and hard to give different levels of headroom. It’s best for blues, jazz, and country guitarists thanks to its clean breakup and long sustain.

2. Svetlana 6L6GC

Best Tubes For Marshall Jcm 900


  • Medium rated
  • Beam power tetrode
  • Ideal for overdrive
  • Moderate distortion
  • Max plate Watts - 30 W

The Svetlana is ideal for overdrive and gives clarity in the sound with plenty of sustain. It has a well-balanced sound that’s not too bright on the highs and not too heavy on the lows. It’s a medium-rated tube and provides moderate distortion of the sound at the full range of frequencies.

3. SED Winged C 6L6GC

Best Tubes For Marshall Jcm 900


  • Matched pair
  • Beam power tetrode
  • Gold plated grid
  • Max plate Watts - 30 W

The highly sought-after SED winged C tubes are considered the holy grail of power tubes. These tubes deliver unequaled quality and depth in sound with clear harmonics. They give a pronounced tone for both the high and the low and pack a punch. The extra rugged build and extra bracing help reduce monophony and mechanical stress.

Unfortunately, they’re currently out of production, which makes their demand very high.


Best Tubes For Marshall Jcm 900


  • Classic Pentode build
  • RCA- style back plate
  • Octal power tube
  • Ideal for low-end

The Tube amp doctor, commonly known as TAD, is a great and affordable tube at 30 watts that offers very clear highs. It’s a remake of the GE 6L6GC small bottle. It’s a durable power tube that’s guaranteed to last long. It has more tamed highs than the rest but a strong reliable mid that gives a great sense of fullness. The bass is good, but it lacks the extra power compared to the Tung sol.

5. JJ 6L6GC

Best Tubes For Marshall Jcm 900


  • Matched pairs and quads
  • Octal power tube
  • Beam power pentode
  • Max plate watts – 30W

The JJ 6L6GC tubes are some good power tubes that offer a nice warm tone. They have rugged thick glass for durability. They have high gains and quality sound at all levels with pronounced lows and bright highs. The tubes are available in low, medium, and high for flexibility in headroom. The overdrive is tight with a bit of a bite. Also, the lows on this are well established, and overall it has a fairly good balance of frequencies.

What to Consider When Buying Tubes for Amps?

Navigating the world of tubes is a difficult job, as there are many different brands and types of tubes. First off, it’s important to know the kind of tone you’re going for, as this will help you significantly in narrowing down your options. Consider the frequency responses for the lows, mids, and high, as well as the microphonic and noise levels.

You can also consider other brands. You’ll find that different brands are known for different characteristic tones depending on how they make the tubes. Ultimately, each type will have its strength and weaknesses and will be suited for particular genres more than others.

When Should I Change the Tubes On My Amp?

An easy way is to purchase a tube tester, which can be used to test specific characteristics of a tube and help you know its state.

If you don't have one, no need to worry. There are multiple tricks you could use to test your tube state. To test the tubes on your preamp, simply tap each tube lightly with a stick or pencil while the amp is on. If you hear loud crackles or rings, then it’s time for a change.

As for the power tubes, you can check for discoloration on the screens and shake them to check for any rattling. Luckily the JCM 900 series comes with a built-in fail-safe switch that indicates power tube failure.

Choosing the Best Tubes for Marshall JCM 900

As you continue in your guitar journey, you’ll come across different types of guitarists who will all tell you what they think are the best sounding tubes for a particular amp. Ultimately, with time, you’ll also develop a taste for what works best for you.

Even then, we hope that when it comes to the JCM 900, you at least have a starting point on which tubes to get.


  • Best Tubes For Marshall Jcm 900

    I have been a singer, songwriter, and guitarist since 2005. I has a bachelor's degree in music and has extensive experience in writing educative music material. In my free time, you can find me eating. Wherever there is music and food, Eugene is probably nearby!

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