Replacement Valve Kit for Marshall JC900 SL-X 50W (3 x ECC83 1 x Balanced ECC83 2 x Matched 5881)

Replacement Valve Kit for Marshall JC900 SL-X 50W amplifier 5881 version


In Stock

499 in stock

All single valves, matched pairs and matched quads are fully tested in our warehouse before dispatch. These valves will guarantee awesome tone and amazing power. You WILL hear the difference. So get your amp sounding better than ever. Order your replacement valves today.


Need a replacement valve kit for Marshall JCM900 SL-X 50 watt amplifiers? 

This replacement valve kit for the Marshall JCM900 SL-X watt head will get your amplifier sounding better than ever. These superior quality valves will give you a significant upgrade in both tone and power. The best value for money amplifier valves on the market today.

Important Note: This amplifier was produced in two versions. One amp uses 5881 power valves and one uses EL34 power valves. Check which valves you currently have before you order.

This superb quality valve kit is the 5881 version and comprises:

  • 3 x ECC83 preamp valves (also called 12AX7).
  • 1 x Balanced ECC83 for the phase splitter position (V4)
  • 2 x matched 5881 power valves/tubes.

We always recommend JJ valves for the Marshall JCM900 SL-X amplifier. This is because they guarantee a superb tone at a very attractive price. We think these are the best valves/tubes for this amplifier. You can order these amplifier valves singly or as matched pairs but it is always recommended that you change all your valves at the same time if you possibly can. 

So treat yourself to a brand new set of gorgeous sounding valves today. Restore the power and clarity to your Marshall JCM900 SL-X guitar amplifier.

  1. Awesome tone. This is what matters most. The number one priority for any Marshall owner has to be the tone. Warm, rich, fat and juicy are the words that best describe the sound from these valves.
  2. Sustained valve/tube power to make the most of every stage in the amplifier chain. It is the balance between volume and tone that distinguishes a great valve from a mediocre valve.
  3. Long valve/tube life.  Guitar amps by their very nature have to be built to take a lot of knocks. This is also very important when it comes to the amplifier valves themselves.

Do you have any questions about this valve kit?

If you have any questions about replacing your valves please drop us an email. One of our team best suited to answer your question will get straight back to you.

We have more than 30 years experience so we are sure we can help.

If you have never changed your valves before, please take a look at our very helpful FAQ section before you contact us.Here you will find the answer to most questions as well as lots of useful hints and tips.

The best replacement valve kit for the Marshall JCM900 SL-X 50 watt amplifier on the market.

  • Every valve kit is carefully selected, fully tested, digitally graded, balanced and matched before we ship to you.
  • We have a range of fast delivery options with full tracking and insurance. So you know that they will arrive safely.
  • Global delivery – we ship all over the world.

About the amp.

If you love the Marshall overdrive sound this amp really delivers. It performs best when pushed hard but it does have the luxury of a half power setting which is very useful.

It was supplied with two power valves options, so as we say above, make sure you check which version you have before you place an order.

This is a superb amp for classic rock and blues and is generally very highly regarded.

Tubes for sale for Marshall JCM900 SLX 50 Watt amp

Our JJ valves give awesome tone and restore the power and clarity to your amp.

All valves 100% guaranteed. Carefully matched and selected.

Additional information

Weight0.45 kg
Dimensions26 × 21 × 17 cm
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Replacement Valve Kit for Marshall JC900 SL-X 50W amplifier 5881 version

Replacement Valve Kit for Marshall JC900 SL-X 50W (3 x ECC83 1 x Balanced ECC83 2 x Matched 5881)