You’ve all seen ‘em: bedroom amps, mini- or micro-stacks, practice amps or whatever you may call them, they all share the same promise: Classic tone in a small, affordable package. Well this installment of Tech Talk is here to show you why that’s pure bullshit meant to bedazzle the ever-so-naïve young guitarist.

1. It has nothing to do with wattage, and this is a more complex issue than it would seem at first glance. And in case you missed it, the myth is that more watts = better tone. As better tone is subjective, it becomes immediately apparent that all such assumptions are flawed to begin with. But let’s dig deeper:
   • More volume might imply better tone: this is because of the equal-loudness contour (the fact that we perceive sounds differently as a function of their volume). It might also be related to the rather visceral sensation of high-SPL sound resonating and shaking your body (and everything around it for that matter). However, an amplifier’s power is not the only factor that defines SPL and consequently perceived loudness: there’s also driver (speaker) and enclosure efficiency and the nature of the programme (what’s coming out of them—a distorted guitar would sound much louder than a clean bass at the same SPL). So keep in mind that while it’s easy to make an uncomfortably loud small combo that doesn’t mean it’ll also sound good.
   • Poweramp saturation myths: the general consensus it that you must play a tube amp very loudly to get the best tone out of it. This is because of power tube saturation, which apparently is the Holy Grail of guitar tone. The issue is vastly covered at Amptone.com so I won’t get into it. Suffice to say this only applies to amplifiers with a tube power stage; the only reason one might turn up a solid state amp is the one discussed above (more volume). Solid state poweramps are designed never to go into audible distortion because that would sound terrible (though I’m sure there are people in this world that would actually like it).
   • Headroom and distortion: I’ve assumed that your goal is a distorted rock tone but what if what you’re after is a squeaky-clean sound with accurate dynamics? The peak-to-RMS ratio of a guitar’s signal can be quite extreme, which means you’d need a lot of power to reproduce those loud attacks, even if the “body” of the note is at a much lower level. Granted, clipped peaks are not as obvious when they’re short and far apart so guitar amps can “get away with it”. This is particularly true for tube amps, where the clipping is softer so even less obvious. This is why people say tube amps sound louder than solid state amps of equivalent power: the sound of the former is actually more compressed, i.e. you can turn it louder without noticing much distortion.
     By now you might be thinking “so if I want more headroom I should get a tube amp”. Well, maybe not. I know I’m biased against ancient technology but let me put it this way: an EL34 pentode is about 12EUR and will output around 20W in class AB. An LM3886 chipamp is only about 4EUR and will output at least 40W, plus it doesn’t require a 300V supply and it has internal thermal protection and current limiting. Factor in the added weight and component cost of a tube amp and you’ll soon realize it’s actually cheaper to buy ten times as much solid state power. Remember though, this is about headroom, not pentode saturation or tube tone in general.
2. It has everything to do with size. Here’s where the specific shortcomings of small combos come into play:
   • Small speakers can’t reproduce low frequencies: at least not the kind we use in guitar amps. That’s just how the laws of physics play out. It’s no coincidence that a Pignose sounds different than a fullstack. You can’t build a speaker that’s also loud, wide-bandwidth and small. In fact some guitar players use a woofer or bass cab along with their 4X12” or whatever. Some use bass cabs exclusively. It’s also the reason why most speaker systems (outdoor event systems in particular) use three sets of drivers: woofers, midrange speakers and tweeters. Some even use subwoofers and supertweeters.
   • Small enclosures aren’t helping: people have been developing enclosures for more than 50 years and they’ve sure come a long way. Except guitar cabs. Poor neglected guitar cabs have always been built with convenience and material economy in mind and not audio performance. This is how people have come to associate a “classic guitar sound” with what is essentially poor speaker design. The heart of the problem is again in the low frequencies. You can read the gist of it on Wikipedia.

So here it is in a nutshell: Small combos usually sound “thin” even if they are reasonably loud. This is because of speaker and cab design; put it through a 4X12” and you will be pleasantly surprised. Of course then it would stop being a small combo. However you don’t have to use a half stack to get a nice full tone, as half stacks aren’t particularly well-designed to begin with. There’s no reason why small (or let’s say reasonably-sized) combos have to sound bad, it’s just that people keep buying them and thus manufacturers have no reason to design better products.