Blog

The Fender Twin amplifier is one of only a handful of amplifiers that has performed a major role in shaping the sound of the electric guitar. It is one of the true “game-changers”. Its legacy lives on through the artists who have used it to create some of the most iconic songs of our time. […]

One of the most common questions we get asked is why is my amp starting to sound a bit noisy these days – and are the valves likely to be the culprit? The first step is to identify whether we are talking about hum or other weird noises like crackling, popping, or squealing? Let’s look […]

This question comes up several times a week – and for very good reason. If you read your amplifier manual, those manufacturers that mention this subject will normally say that the average life of a set of valves is either 500 or 1,000 hours playing time. As a result, those are the two statistics most […]

The 5881 valve (5881 tube) is a power output tube used in some makes of guitar amplifier. The 5881 is towards the lower end of the power spectrum for output valves. It can handle a maximum of 23W and so a pair of 5881 valves would give you about 46W tops. 5881 tubes (5881 valves) […]

Always on the quest to pack more power into a single tube, the 6550 was launched in the 1950s by Tung-Sol. Tung-Sol is an American company who specialise in vacuum tubes. They still sell their reissue of this famous valve. The 1950’s version was rapidly improved in the 1960s to produce the MKIII version. Since […]

The KT77 Valve. Buy them here and learn all about this awesome valve. The KT77 is a power output valve used in some guitar amplifiers. Marshall have used these in several of their designs in the past. Normally you will find the amp can use either a KT77 valve or an EL34. They are fairly […]

Rectifier valves are used in a large number of vintage and reissue guitar amplfiers. For example the GZ34 (5AR4) rectifier from JJ Electronics. This version of the GZ34 has a thick glass envelope and robust electrodes making it the perfect workhorse for those guitar amplifiers which use tube rectification. Examples of guitar amplifiers which use […]

This short article deals with power valves for guitar amplifiers. There is another article which covers preamplifier guitar amplifier valves and also rectifier guitar amplifier valves. It is not intended to show you how tube amps work or the detailed operation of a tube amplifier. There are only three basic types of guitar amplifier valves, […]

What is the 6V6 valve? To keep this short article suitable for everybody, even total novices, let me first explain that the 6V6 valve is a power output valve used mainly in audio stages. I write these blogs mostly for guitarists as the 6V6 valve is used in quite a few different models of guitar […]

The 12AY7 valve versus the 12AX7 (ECC83) valve. The 12AY7 valve (also known as the 6072) is a 9-pin tube. This is actually two valves in one glass envelope. It is what is called a ‘double triode’. It was originally designed as a low noise tube and was actually developed before the 12AX7 (ECC83). The […]

Have you ever wondered about the difference between the 6L6GC valve and the 5881 valve? It can seem so confusing! Some forums say the 5881 is equivalent to the 6L6GC and others say not. You can be left wondering if the 6L6 a ‘like for like’ replacement for the 5881? You are probably reading this […]

12AT7 (ECC81) Valves For Sale. We sell the superb 12AT7 valve, also known as the ECC81, made by JJ. JJ are one of only three valve manufacturers in the world so you know you are buying from the source. Don’t pay more for rebranded versions of exactly the same valve. Click here to see our […]

One question we are often asked is this: Is the ECC83 equivalent to the 7025 valve? The short answer is yes in that you can swap a 7025 valve for an ECC83 and your amplifier will work fine. The 7025 valve is a low hum and low noise version of the ECC83, but will you […]

The 12AX7 Valve (or 12AX7 vacuum Tube) is a small preamplifier valve which is identical to the ECC83 – same valve, just a different name. It has two identical triodes both of which have a high voltage gain. It is used in 99% of all guitar amplifiers. RCA engineers developed it around 1946 and released […]

Do you own a valve guitar amplifier and wondered what ‘cathode bias’ means? Have you heard of ‘biasing’ but perhaps are a little confused about what bias means and in particular what cathode bias means? Don’t worry – you’re not alone! Biasing is a highly confusing subject for the owners of valve guitar amplifiers. The […]

This short article describes something called microphony in guitar amplifier valves. Microphony particularly occurs in the preamplifier valves, or rather it’s more accurate to say that microphony is more noticeable in preamplifier valves. That’s because these valves are at the start of the amplification chain and so any noise due to microphony is very greatly […]

Firstly let’s sort out the confusion. ECC83 or 12AX7? They are identical. ECC83 is the British designation and 12AX7 the American. Since the Americans invented it (RCA in 1946) I guess it should really be called the 12AX7. The initial “12” in the designator implies a 12-volt heater requirement; however, the tube has a centre-tapped […]

NOS valves means New Old Stock Valves. NOS tubes means the same of course. We know what a valve is of course but what are New Old Stock valves? NOS valves (New Old Stock) are valves which are brand new, never used, boxed valves manufactured years or decades ago. NOS valves can be fifty years […]

The phase splitter valve in guitar amplifiers. We are often asked by customers “What is the phase splitter valve (or phase inverter valve) and is it special or different from the other valves in my valve guitar amplifier?” Hopefully, this short article will explain what the phase splitter valve and clear up any questions about […]

Understanding fixed bias in valve guitar amplifiers. Fixed Bias is a term which guitarists often mention. But what on earth is it? Do you have a valve guitar amplifier? In that case, you have probably heard of ‘biasing’. It can be a very confusing term.  It’s even more confusing as you have probably also heard […]

The search for the best guitar amplifier valve is akin to the search for the Holy Grail! As you might expect there is no best guitar amplifier valve for your tube guitar amp! Just as there is no best car tyre or best television set or Hi-Fi. In short, these matters are highly subjective and […]

Deciding to buy classic vintage guitar amplifiers is a tricky question. It’s a bit like asking ‘should I buy a 60-year-old classic vintage car’? Answer: Yes if you have always lusted after one and don’t mind the endless maintenance and ‘money sink’. No, if you are chasing some Holy Grail sound which is probably more due […]

Red plating only occurs in one group of amplifier valves. Guitar amplifier valves fall into two main groups (ignoring power supply valves) and red plating only occurs on one group. The two groups are preamplifier valves such as ECC83 (12AX7) and power output valves (such as 6L6, EL34 etc.). Red plating can occur in the […]

If you own a valve guitar amplifier you will almost certainly have a standby switch on it.  Traditional thinking says that the standby switch is there to protect the amplifier output valves. Note: your guitar amplifier has two sorts of valve – preamplifier valves (the smaller ones) and amplifier output valves (the larger ones which […]

This short article deals with preamplifier valves for guitar amplifiers. There is another article which covers power guitar amplifier valves and also rectifier guitar amplifier valves. It is not intended to show you how tube amps work or the detailed operation of a tube amplifier. There are only three basic types of guitar amplifier valves, […]

How do I Choose The Best Valve Guitar Amplifier For Me? Are you looking to change your amp and thinking of going valve? There are several questions you need to answer before you can decide on which valve guitar amplifier is best for you. Top tips for choosing a valve guitar amplifier What power do […]

Have you ever wondered how valves work in tube amps or what are tube amps? Guitar Amplifier Valves The Basics There is the six volume textbook answer and the two page answer to how guitar amplifier valves work. I expect you’d like the shorter version! To understand how valves work and the basics of guitar […]

Biasing Guitar Amplifiers. What’s Involved? Since we supply valves for guitar amplifiers we are often contacted to ask us about biasing guitar amplifiers. Biasing guitar amplifiers (biasing tubes) is a highly confusing subject for the non-technical and for good reason. Biasing guitar amplifiers IS confusing! The first thing to say is that although all the […]

JJ Valves. At the time of writing we only supply JJ Valves from JJ Electronics. Sometimes asked why we don’t supply a larger range of valves from different manufacturers. This was a deliberate decision on our part, only to sell JJ valves. When we started AmpValves we looked around at the competition and found a […]

Ever wondered which is the best amplifier valve out there?  Are some makes of guitar amplifier valves are better than others? If you own a valve amplifier or tube amplifier (http://en.wikipedia.org/wiki/Valve_amplifier) this is a very contentious question! The short answer is ‘yes’ there is a best amplifier valve— but not maybe for the reasons you […]

Working with valve guitar amplifier is not dangerous in itself as long as it is not opened up. That’s fairly obvious otherwise they would not be sold! The danger comes if the innards are exposed and you touch a live component. In this respect they are far more dangerous than a transistor amplifier because they […]

This is a question I often get asked. And with good reason. As guitar amplifier valves age they just become less and less efficient. The trouble is, the degradation of sound in the valve guitar amp is very slow. So gig to gig you won’t notice anything dramatically wrong with your guitar amplifier valves. But […]