Choosing the best wattage guitar amp — Anatomy of Guitar Tone

The question comes up quite a bit about what is the best wattage guitar amp to buy. It's hard to find the perfect volume amp that covers all applications. Especially if there is a wide variety of gigs, you do. Choosing an amp judging by its wattage alone may be a little misleading.

Let's try to narrow down some choices in this article. To do so, we must first start with how you use your amp. There tend to be two camps when it comes to tube amps.

1: Using the amp to get some natural tube overdrive:

These players use their amp for a good portion of overdrive. The amp volume can sit anywhere between 5-10 depending on how much grit you want and what guitar you're using.

These players may still use a boost, overdrive, or fuzz pedal to get more gain. Fuzz pedals sound considerably different run into a clean amp as opposed to a dirty amp.

The Hendrix fuzz tone was a combination of a Fuzz Face pedal and amp overdrive via his Marshall Plexi amps.

2: Keeping the amp clean with lots of headroom.

David Gilmour playing through Hiwatt DR 103

These guitarists like to have a clean foundation at their amp and use pedals for gain. Even if this style of guitarist turns their amp up to 4-5 to be heard, they require it to remain clean with no overdrive.

David Gilmore is an excellent example of this. He uses Hiwatt DR103 amps which are very loud and incredibly clean tube amps. From there he uses a mixture of pedals to change his tone.

Jury

There is no right or wrong. Each approach has its advantages and disadvantages. It's a good idea to know where you sit most often when choosing amps. You're going to have to consider how much headroom you need and it can be misleading.

Band configuration

When you are pondering headroom, you need to think about the band you're playing in. The environment can reveal the amount of volume it requires to remain audible while everyone is playing.

This math can be a little tricky because you have to consider the players and how they interact with their instruments.

Solo/Duo gigs

If you're playing by yourself or accompanying a pianist (no bass, no drums) you can get away with a very low wattage amp. 5 watts covers it all. You would be surprised how much volume a 5-watt amp can put out.

Depending on the room you're in, cranking a 5-watt amp can be overpowering if it's a quiet project. However, often, it sits in a great place.

If you need the clean headroom, a 12watt amp allows you a little more flexibility.

I've used both of these wattage amps on many gigs. With an acoustic act, I have never run out of volume.

Bass trap

Bass can complicate things. It depends on the bassist. If it's upright bass, a 5 or 12-watt amp is plenty.

If you're dealing with an electric bassist who is playing loud and brings a high powered amp, you may get buried.

My advice for that is not to buy a bigger amp but get the bassist to bring a smaller amp and play quieter. Alternatively, find a different bassist. A volume war with an acoustic trio is never a flattering sound. If everyone balances their sound coming off the stage or in the room, the experience is more pleasing.

Drums

Ok, we all know what happens when the drummer shows up. Food disappears from cupboards, and tabs don't get paid, weird smells emit from the stage, and all of a sudden, your setlist turns into a workout playlist. I know, I think I’m funny. I grew up a drummer, and I have very close friends that are amazing drummers. I still can't resist making a joke here and there.

Drums significantly alter the amount of volume you need from your amp. Drums take up sonic space. A drum kit played quietly puts out more dB's then you realize.

The quiet drummer

If you find one marry them!! Sorry, I couldn't resist again. I would say a quiet drummer is a drummer that plays with brushes or lightly with sticks. Think of the volume of most jazz drummers.

“a quiet drummer is a drummer that plays with brushes or lightly with sticks”

In these situations, I can get away with using a 12-15 watt amp (more on the specifics of wattage later as that can be misleading).

12-15 watts generally gives me enough headroom to be heard and allow a little grit from the amp. If you need to preserve absolute cleanliness (meaning you're no fun), then an amp in the 20-22 watt range is splendid.

You'll notice that when I need more clean headroom, I'm adding on 5-10 watts for each class.

I've used this method successfully for amp pairing on a variety of gigs. Scenarios can be everything from a songwriter gig to a wedding style gig.

Animal

If your drummer is aggressive, then we need to make some adjustments to our choice of an amp. Some styles of music just can't be played delicately, and there's nothing wrong with that. There is a big difference from someone playing Minor Threat songs at an aggressive volume to someone playing Stevie Wonder at an aggressive volume.

For some types of music, it's appropriate. For aggressive gigs, I like to have an amp that is in the 22-30watt range. The extra wattage allows me to get a little gain from the amp but still audible onstage.

A 30-watt amp like a Vox AC30 can be quite a loud amp. At 30 watts you would be surprised how much you can blow out people. There are even some festival stages that I find it hard to crank an AC30 fully.

‘Punching Bag

As we start to approach this aggressive volume range, we start getting near the danger zone of too much volume. With a bigger amp, it doesn't take much for the volume to be overbearing, which brings up the point about choosing the right amp.

A 100-watt amp isn't going to sound pleasing on volume 2. So even if you need plenty of headroom, choosing too much headroom can have diminishing returns. Opening up an amp to around 3-4 can bring the amp to life rather then choking it on 2 even if you're looking to keep it clean.

It's also worth mentioning that high headroom amps can be unwieldy with fuzz pedals. When I'm dealing with high output pedals, I like having a lower ceiling. Kicking an MKI Tonebender into a Twin Reverb on 2 can yield some surprise volume jumps as the Twin has limitless headroom.

Siblings

Playing with a second electric guitarist can be a real cog in the wheel. Two guitars sit in the same frequency range. If they're both electric, they share even more sonic DNA. Two guitars fight harder sonically because you're both competing for the same frequency space. That doesn't mean it won't be loud. It's plenty loud, but the sound is muddy and undefined.

When I get to play with a great experienced second guitarist, I have loads of fun. Seasoned players know how to ride their volume knob. They know when to sit back or when to come forward. They hear when our tones are competing and adjust their tone or register they're playing their instrument.

When I have to play with a second guitarist who has figurative blinders on, it can be extremely frustrating. This guitarist never touches their volume knob. They never pay attention to where you're playing on the guitar neck. They eat up all of the space. If there is oxygen in the room, they find it — mouth breathers.

“Seasoned players know how to ride their volume knob. They know when to sit back or when to come forward.”

With an experienced guitarist, I don't have to be too worried about bringing an amp that is louder then I would typically pair with a band. If the guitarist seems to be less experienced or not aware (insert facepalm), then I bring a louder amp.

I find this happens a lot with electric rhythm guitarists. They play at the top of the volume range with nowhere to go except back which some never do. If I need to get above them, a 12-15 watt amp isn't going to cut it. I would need something in the 22-28watt range. So when I solo, I don't get buried. At 12-15 watts, my general second guitar parts won't get lost. However, 12-15watts doesn't give me any muscle to get above the band.

“the more you balance your sound on stage, the better it sounds in the room. ”

The best solution is to work on band dynamics and use a smaller amp. It sounds better then guitars fighting for volume which ends up overpowering even a loud drummer. As mentioned already, the more you balance your sound on stage, the better it sounds in the room. Think of the stage sound as the mix, and the PA amplifies that.

Subs

One of the surprises of playing on a big stage or any stage with subwoofers is how much they can eat up your guitar volume. I've had the experience showing up to a soundcheck and acclimating to a stage volume only to be shocked when the house got turned on, and I disappeared.

Smaller amps may seem loud, but they don't have the girth to keep up with subs. In-ears solve the issue. However, if you're not on in-ears, it's a much bigger issue.

You could, in theory, put your guitar amp into the stage monitor to hear yourself more. Some guitarists are ok with that. However, I can't stand the sound of my guitar amp in the monitor. Occasionally I get on a stage that has high-end monitors. Most of the time they're barely adequate.

Playing Mountain Jam 2019 on a large stage using a 40-watt amp

Adequate doesn't warm my heart. I rarely feel monitors represent the tone coming from my amp. Stage monitors tend to sound shrill and dry. It sounds like paper vibrating. I like that about as much as walking behind an NYC garage truck in August.

In case it wasn't clear, I hate stage monitors! Ok, I still have some things to work out with my therapist. Baby steps!

Playing Pete’s Candy store 2019 using a 12-watt amp

I use my amp as my stage monitor. I don't play excessively loud. However, I do play loud enough to hear myself. I put a plexiglass shield in front of my amp to prevent too much volume going to the audience.

For this environment, I use an amp that's between 28-30 watts. The extra volume allows me to have enough power to stay above the invasive subs on stage.

100 watts or bust!

I bet some are wondering where are the applications where one would need an 85 or 100watt amp. I haven't found one these days. There was a time when the guitar amps onstage had to act like a sound system. They needed to be ultra-loud.

Stage volume doesn't need to be nearly that loud now. A 100-watt amp would be overbearing even on a festival stage. I have personally never needed more than 40 watts. I've played on some substantial stages in large venues too.

It's for this reason you see more and more lower wattage amp choices. I'm not saying a 100 watt Marshall Plexi doesn't have a sound. It does. However, it's louder then you'll ever need. Also, you may never actually achieve that volume to reach the sweet spot. A Plexi on 5 rips yo' face-off!

I feel the same way about Fender Twin Reverbs. At 85 watts they're hard to control and sound bad on low volumes. I've seen many a gig where a Twin Reverb has blown out the rest of the band.

What's in it Watt-son

I mentioned earlier about wattage being misleading. Wattage isn't the only indicator of how loud an amp is. Most guitarists use it as a gauge just as I did earlier. The reason I gave a range though was to account for the volume differences in various amps.

For instance, a 12-watt amp can technically be louder than a 15-watt amp. Let's look at the Fender Princeton and the Vox AC15. The Princeton is a 12-watt amp. However, it stays cleaner longer than the AC15, which is a 15-watt amp.

Many factors can contribute to this amp headroom, including speaker efficiency. Some speakers break up faster than others. If you have a less efficient speaker in a 15watt, the 12-watt amp could stay cleaner longer.

Another point to consider is the rectifier. Solid-state rectifiers are cleaner and don't sag. Sag is what happens on a tube amp with a tube rectifier when you have the volume cranked, and you hear the volume duck for a second when you hit a note or chord. The amp compresses. To some, this is a desirable effect. The amp gets squishy and feels gooey.

To some, sag is a hindrance because it also can make the amp feel slow and loose. Individual players may prefer solid-state rectifiers because they feel fast and are tighter on the low end since they don't sag. They both have their advantages.

Transformers

The transformer can change how much low end is coming out of your amp. Leo Fender used this to his advantage back in the day when speakers were getting blown frequently. He would limit the size of the transformer to reduce the amount of low end that goes to a speaker and potentially blowing it at louder volumes.

The amount of girth or low-end energy a smaller amp has can vary as they may have different transformers. If a smaller amp has a bigger transformer, it produces more low end. However, if it has a smaller transformer, it can lack a low-end push.

They both have their purpose. However, if you're using your amp as a stage monitor or to fill the room keep in mind a small amp with a small transformer won't fill up the room the same as a large amp with a large transformer. Extended low end is the advantage of a bigger amp sometimes — a cranked large amp won't sound as small filling the room.

For instance, playing a Fender Princeton at max with a moderately loud band where the amp is at its audible limit sounds smaller than desired. You'll notice 5-10 feet out in front of the amp it sounds thin. More so than a 28-watt amp even if they're playing at the same volume.

Tonal balance doesn't seem to be an issue when you match the amp to the volume of the band. I notice the thin amp tone a lot with loud bands that use small amps that are barely keeping up.

In the right setting (if miked and running through the house) or with a quieter band, a small amp can sound full and not overbearing. On the other end of the spectrum, a big transformer sound can be overpowering in quiet situations.

Package description

A 25 -watt Celestion Greenback 25 speaker

These are just a few things to keep in mind when trying to find the right amp wattage. 22watts from one brand of amp doesn't equal 22watts from another brand.

Even within the Fender line, there are different combinations of wattage, transformer size, speaker efficiency, and rectifiers. Just cause the amp is more wattage doesn't mean it has a big transformer. You have to do some investigating.

Remember the check variable components with Marshall and Vox as well. A Marshall amp at a similar wattage as a Fender may seem louder. Marshalls tend to project a lot.

I just recently got my hands on a new Marshall SV20H. It's a 20 watt Plexi which Marshall has never done. I was very excited as I happen to love the Plexi tone.

I would classify the SV20H as a loud 20watts. There is a tone DNA of each amp. Marshall's tone print is very midrange forward. The mid bump allows it to cut through a dense mix. Especially when running through a cab with more than one speaker. A single speaker can reduce some of the volume.

The SV20H has a 5-watt switchable option on it as well which is a feature some modern amps have. The scaled wattage can allow you some more flexibility with varying environments.

Cabinet

You also need to consider whether you're using a closed back or open back cab. Open back cabs fill the stage more as sound emits from the front and the back. Cab spill can be a plus or a minus.

There are times when filling the stage with your guitar amp is problematic to the other musicians. A closed-back cab is much more directional. Pretty much where you point the speakers is mostly where the sound goes.

Closed-back cabs have their drawbacks as the sound can be pointy. Right in front, it may be deafening, but standing a few feet off to the side you won't hear it all that much.

Usually, people choose a cab based on their tonal preferences. However, considering how you want your guitar tone to spill is a useful tool.

Behind the glass

For some reason, guitars players have a real issue when they see a plexiglass shield. Some guitarists feel caged. It seems as if a sneeze guard as they call it is a bust to their ego. Volume isn't a right of passage. Yes, most tube amps sound better turned up. However, turning up to achieve the best tone from the amp doesn't mean it has to blow out the audience.

The joy of using an amp shield is that you can play loud-ish and contain the amp. It also shoots the amp sound upwards so if you stand close enough to it, you'll hear the amp better. Everyone wins!

Plexiglass in front of my amps at a concert

I tour with a shield all the time. A majority of the time, I use it. It helps when you have those occasional venues where an amp is being a little too loud. It allows me to keep my amp the same volume in different rooms. I can keep my gain staging the same night to night.

“using the shield allows the amp to feed the room in a non-direct way. ”

Often when people complain about the guitar amp being too loud, it's because the speakers are hitting them in than face. Most of the time, using the shield allows the amp to feed the room in a non-direct way.

Of course, there are times where this is still too loud. However, if I've picked the right amp that sits within a range for the types of rooms I'm playing, it's not too often I have to adjust. So that's the key, to land within a range of correct volume for the gig.