We all know the cliche, the volume mad guitarist who is always trying to get more and more powerful amps in order to get ‘that’ sound. Back in the day the holy grail was the 100W stack, or better still several of them chained together. Now you can get 200W amps from more than one maker. Another company has perpetuated the arms race with 300W and 400W guitar amps. Do we really need all this power?
In a word, No. I’m going to explain why, and what size amp you actually need. Although I’m addressing this to guitarists, it applies to anyone who uses their own amplifier to get the sound out of their instrument.
Your amp is only for you to hear
In this post I’m going to be talking about gigs where the amplifier is mic’d. Its sound is going through the PA as well as coming out of their amp. I’m also assuming there is a sound engineer doing the front of house sound; the band aren’t doing it themselves from on stage. There are some on stage monitors, ideally one for each band member. So a relatively professional set up. This is normal these days in anything bigger than a venue of around 100 people capacity. It doesn’t mean you’re ‘big time’ necessarily. A lot of bands will achieve this level if they’re any good.
If you don’t know whether you’ll have this kind of set up at your next gig, you should. Start asking questions. It affects how you prepare and what gear you should bring.
With this kind of set up your amp only needs to be loud enough for you to hear it. This is critical. I’m going to say it again. Your amp only needs to be loud enough for you, and only you, to hear it.
Why? Because there’s a microphone right in front of your amp, picking up the sound and sending it through the PA. That’s what the audience should be hearing. You have a sound engineer who is carefully mixing the sound through the PA for maximum clarity. If you have a massive amp that’s deafening everyone in the first 5 rows and drowning out the PA your band is going to sound rubbish. The engineer can’t do anything about it.
If the rest of your band want to hear you they will ask the engineer to put some of your sound in to their monitors. That way they can control what they hear and can make sure they can hear themselves which is crucial for a good performance.
If you take nothing else from this post, please at least remember: as soon as there is a microphone in front of your amp, it only needs to be loud enough for you to hear it. Leave the rest to the engineer.
The world has moved on. Guitarists haven’t.
I know what you’re going to say. “But Hendrix / Gilmour / Townsend / Angus / Van Halen / etc. used a 100W stack. I want to sound like them so I neeeeeed one to get the right sound.” No you don’t. Let me give you a brief history lesson.
In the olden days (60’s / 70’s) amplification technology was a bit rubbish, both for guitars and for PA systems. You couldn’t put anything more than vocals, and maybe the drums, through the PA. They didn’t have enough channels. Even if they did the amps and speakers couldn’t reproduce lots of competing sounds accurately. If you tried to put all the instruments through the PA the sound turned to mush.
Because of this, the guitar amplifiers had to project the sound all the way to the back of the room. As ‘pop’ music became more and more of a phenomenon and bands played bigger and bigger venues they needed bigger and bigger amps. That’s why they used stacks of cabinets with 100w amps chained together. It was necessity more than artistic choice. Many of the greats from those days now suffer badly with tinnitus because they had to stand so close to these huge rigs blasting out noise to the back of the venue (Pete Townsend and Jeff Beck are well documented examples).
Nowadays, PA technology has come on leaps and bounds. It can faithfully project the sound of every instrument in your band, even if you’re a 35 piece world-music ensemble. All it needs is to get the signal from your amplifier and it will do the rest. Jam a microphone up against the front of the amp speaker and it can’t fail to pick it up, even if you’ve got a 1W amp. You don’t need an amp that can project to the back of the room any more. You just need one loud enough for you to hear.
Unfortunately guitarists haven’t caught on to this yet. They’re still looking at the technology used 40 years ago and thinking that’s what they need in order to sound good. It’s like using a wooden racket to play tennis. It’s just not appropriate given the technology in use today.
It’s all for show
Here’s one of the worst kept secrets in rock: You know those bands who have a ‘wall’ of amplifier cabinets at the back of the stage when they gig? AC/DC are a notable example. The cabinets are empty. They’re for show. They don’t have any speakers in them and they don’t make any noise.
Somewhere behind the wall of faux cabinets there will be one or at most two amps connected to one or two cabinets, with a microphone in front of them. That’s what’s coming out of the PA. That’s what you’re hearing. They are wearing in-ear monitors so they can hear what they’re doing. The cabinets do nothing. If you think they’ve got a ‘massive’ sound it’s not because they can afford bigger amps than you, it’s because their sound engineer knows how to work the sound from that one amp well.
The good news
The good news is that guitar amplifier technology has moved on as well. You can now get really good small amps to suit almost any budget. 20 years ago small amps were considered ‘practice amps’ and didn’t have to sound all that great. Now most manufacturers are producing performance quality ‘small’ amps (by which I mean less than around 30W).
There’s even better news, for those of you wanting the ‘classic’ rock tones of Hendrix, Clapton, Page, et al. Their sound was in a large part due to the fact they had to run the amps of the day on maximum to be heard in a large concert hall. It’s just not feasible for us mortals playing smaller rooms to turn a 100W amp up to 10 in order to get that authentic valve overdrive. But we can now buy a good 5W valve amp and turn that up full. That’s more likely to emulate your hero’s sound than trying to use the same amp they did half a century ago with the volume set to 2.
Enough history, what size amp do I need?
Given that only you need to hear your amp, the defining factor is stage size. How far will you be from your amp? How much competing noise will there be? First, get an amp stand which tilts your amp up towards you. It’s only for you to hear, so it needs to be pointing at your ears. Not at your knees and definitely not at the audience. Just doing that will dramatially improve your stage sound. It also significantly reduces the size of amp you need.
Once you’ve got it tilted towards your head, I’d say that for a stage in a room of up to 500 people you could manage with a 15W valve amp. If you have a very loud drummer or a big stage where you’re further from the amp you might want to go up towards 30W. You’d need to be playing to thousands before a 50W or 100W amp became necessary.
If you play with a very clean guitar sound you might want more powerful amp than if you play rock. That sounds like it’s the wrong way round, but it’s not. The reason is that valve amps can distort when you turn the volume very high even on their clean channel. That’s no problem if you’re playing overdriven rock or metal, but if you want sparkling clean sounds you may not be able to turn the amp up full to compensate.
A little bit of theory
If 15W sounds really small, then there are some facts about amplifier power that you really ought to know and will make you feel better. There’s a whole post coming on ‘loudness’ but just to get you started, here are the important points:
- A 100W amp is not twice as loud as a 50W amp. In fact it’s only a little bit louder (approx. +3dB).
- To make an amp twice as loud you have to increase the wattage by ten times! So to be twice as loud as a 50W amp you would need a 500W amp.
- That means that a 10W amp is still around half as loud as a 100W amp. If you’ve ever been up close and personal with a 100W amp you’ll know that even half its volume is pretty loud!
So the 15-30W amp range I’m suggesting is still plenty of volume – more than half as loud as a 100W amp.
(There are some generalisations in the figures above because perceived loudness isn’t only determined by wattage, but it’s good enough to give you an idea)
I know you want a stack. We all do. They’re cool. But I’ve got one and I almost never use it, because I’m not playing gigs to 2000 or more people (yet!). You would be far better off spending your money on an amp stand and one or two amps in the 15-30W range. You’ll get more use out of them and if you know what you’re doing you’ll probably get a better sound out of them.
Update February 2016: The brilliant That Pedal Show on YouTube has just done an episode on amp sizes and how different sizes interact with pedals. Well worth a watch if this article has interested you.