Amp head watts

darrenw5094

What is the difference between a head with 50w, 100w or 150w....
If you hook each one up to a 4x12 300w cab.....how much different and what is the difference?

Is it a volume thing or what?

Voodu Child

I'll assume you're talking valve-guitar heads...

Watts is the power of the amp. A 50w amp is obviously less powerful than a 150w.

Loudness is a different thing altogether. Through the same cab, a 5 watt head will be half as loud as a 50watt (and not 1/10 as loud as you might think). It's a logarithmic thing,
X% louder = 2^log10(P2/P1) * 100%
where P1 and P2 are the two powers you're comparing.

In laymans terms, a good 50 watt valve head is hellaciously loud (as much as most guys ever need), and 100 and 150 are more so, but not to the degree you'd expect.

100watt and 150watt amps will obviously be more expensive than the equivalent 50 watter (as they have heavier output transformers, which are a very expensive component), and will have more power valves in them (costing more $ again).

darrenw5094

A little bit confusing but i see the point.

Easy option would be for the 50w head......i am just gigging in pubs with cover band.

Hanx for that man.

Voodu Child

darrenw5094 wrote:

A little bit confusing but i see the point.

Easy option would be for the 50w head......i am just gigging in pubs with cover band.

Hanx for that man.

Well, the gist of it is - a 150watt head isnt '3 times' louder than a 50 watter of the same model.

It's 39% louder by formula above

Karl Hungus

If we're talking 50-watts Tube, then that's plenty to play a good sized gig, but if it's solid state, I'm not so sure?

Voodu Child

Karl Hungus wrote:

If we're talking 50-watts Tube, then that's plenty to play a good sized gig, but if it's solid state, I'm not so sure?

Hence the disclaimer in my first post

Yep, a 50 watt solid state amp isn't as fantasically loud as a 50 watt valve-er that's for sure.

mr_fruitbowl

50 watts solid state is perfect for gigging.

Hendrix89

It just so happens that I am going from a marshall 50w solid-state combo to a quality 50w valve head. Will report my first hand experience when the amp arrives next week. I am already fully aware of the difference however!

feylya

I think the rule of thumb is a 50W tube amp is 3 times louder than a 50W solid state amp. 50W solidstate should still plenty for gigging though.