ECC83 Valves and Tubes (also called 12AX7 or 7025) for sale

The ECC83 (also known as a 12AX7) valve is used in the pre-amplifier section of 99% of all valve guitar amplifiers. Usually, there are between 1 and 6 of these valves in the pre-amplifier section. They all do the same thing which is to amplify a smaller signal into a larger one.

The only exception to this is the “balanced ECC83”.

This does a different job in that it ensures the power valves receive an equal (or balanced) signal. The balanced valve is used in the phase inverter position which is nearly always the last one in the preamp chain. That means it is the one furthest from your guitar input jack.

Scroll down to see all the ECC83/12AX7/7025 valves we have in stock.

ECC83 tubes versus 12AX7 tubes. What’s the difference?

In a word – nothing. There is no difference.

In the UK and Europe we call these ECC83 valves. In America they call them 12AX7 tubes. Different name, same valve.

If you have an amp made by a US company they will invariable refer to them as tubes in the user manual. British made amps will usually refer to them as ECC83s.

ECC83 equals 12AX7 equals 7025

Just to add even more confusion they are also called 7025 valves. This is an older term and if you pull a preamp valve out of an old amp it will probably say 7025 on it.

The bottom line is that all these valves are interchangeable and will all work perfectly well in your amp. They all have a slightly different character so trying different brands to see what you like is a good thing to do.

Just remember that amp manufacturers do not make valves, they simply rebrand the big three (JJ, Sovtek and Electro Harmonix).

We include the Electro Harmonix 7025 EH preamp valve for sale in our list below. As we have seen already, the 7025 EH is also a 12AX7 but it is designed to be extremely low noise, low hum and low harmonics.

If you have a noisy amp try one of these EH tubes in your V1 position (that’s the one closest to the guitar input jack) or you can replace all of your ECC83 valves with a 7025 EH if you like.

If you find that the ECC83 has too much gain and your amp is too loud, we recommend using a 12AY7 instead. This will reduce the gain by 50% and give you more headroom.

The ECC83/12AX7 – the most popular preamp valve/tube on the market

This valve can be found in just about every valve amp ever made.

The reason the ECC83 valve is so popular is that it’s actually two identical valves in one. So amplifier designers can get two stages of amplification using just one valve.

This reduces the space needed to house the electronic hardware inside the guitar amplifier and keeps their costs down.