Re: So why ARE tube amps louder than solid state?
These are the views of Stewart Ward, the British amp designer behind the Sessionette solid state amps that some of you may remember from the 80s:
Are valve amps louder than transistor for the same power rating?
The short answer is no. Watts are a precise measurement and is exactly the
same for valves or transistors. Valves do not have some ‘mysterious’ ability
to alter the laws of physics... sadly for some romantics! But there are factors
which can make transistor amps seem quieter. There are three main reasons
to explain this:
1. Valve amplifiers are usually fitted with premium grade speakers. As
mentioned in ‘Speaker Talk’, these can make your amp much louder for the
same input power to the speaker. Unfortunately, transistor amplifiers are
not viewed with much esteem by the general guitar player or magazine
writers. They are, by default, expected to be much cheaper than a valve
equivalent. So the manufacturers of these amplifiers do not invest a lot of
time and expertise at the design stage. Further, most of the expensive
components used are cut down to the bone in order to achieve the ‘expected’
low price. Resultantly, as the speaker is the single most expensive component used in an amplifier, it becomes a cost cutting target! Therefore, and even though it may exhibit a ‘famous name’, it is not usually to the same high standard as the one fitted to a valve amp. One way to cut down the cost of a speaker is to reduce the size of the magnet, as it is the most expensive component in the speaker. This also makes the amp lighter, which is great in helping to save freight costs if the amplifier is being shipped from some far away country. Freight is charged by weight. However, the down side to this is that the smaller magnet means that the speaker is bound to be less efficient, which results in the amp sounding a lot quieter on stage in a performing situation. But, in a shop or at home, it still seems very loud. This is deceptive and lots of guitarists (and reviewers) get caught out by this.
At the time of writing, some guitar speakers are coming onto the market
using ‘Neodymium’ magnets - Celestion’s G12 Century for example.
This newish material enables very small magnets to be made which are
much stronger than conventionally sized ceramic ones. These new magnets
should therefore, not be confused with the traditional ‘ceramic’ type we are
talking about above.
2. Transistor amps are able to deliver more power when you add an
extension speaker cabinet. Whereas, valve amps have their speakers
‘matched’ to the output transformer, which means that the amplifier always
delivers the maximum power into the speakers. As you know, when you connect an extension cabinet you usually have to select another impedance setting using a switch at the back of the valve amp. The often overlooked point here, is that guitarists do not realise that the power quoted by the manufacturer on the front of the transistor amp, is usually the maximum total power the amplifier is able to deliver when an extension cabinet is connected. This means that you should expect to derate the power of a 100 watt transistor amplifier to around 60/65 watts RMS when using just the internal
speaker(s). This makes quite a difference and it is perfectly understandable
why any guitarist might be surprised to find that a transistor amp which says 100 watts on the front does not seem as loud as a similarly rated valve amp... especially when it is likely to be fitted with one of those less efficient speakers as mentioned earlier!
Continues.......
