What’s the difference between guitar amps and bass amps? (The Facts You Should Know!)
We tend to think that companies would do anything to take our money. This can lead us to believe that they want to create a new market niche so we can purchase items we don’t need. Do the guitar amp vs bass amp sound the same when plugged in indistinguishably? I’ve been a musician for over 30 years, so I can tell you the exact answer to that question.
What is the difference between a guitar amp and a bass amp?
It has a straight-forward preamp stage, a high power wattage, and a speaker configuration designed specifically for low and low-mid frequencies. A guitar amp, on the other hand, has a more complex preamp stage, lower wattage, and different speakers that emphasize mid and mid-high frequencies. As you can see, this is just the tip of the iceberg in terms of what makes these amps so diverse. Are you ready to clear this doubt once and for all?
It All Began With A Bass Amp
I’d like to take you back to the middle of the last century. Leo Fender had just put out with his company some good-selling, cheap musical instruments that revolutionized the world. Many brands have attempted to create amplifiers for such instruments without much success over the past three decades. As an engineer, Leo Fender knew how to bring his instruments to life, not as a musician. In addition to creating a legend, he also installed a revolutionary rectifier valve in the circuit to make it one of the few truly reliable and loud amplifiers in the world. During that time, Leo Fender was to music what Henry Ford was to cars. His mission was to create reliable, affordable solutions for musicians. Eventually, that model became the benchmark that defined an era’s sound. Since there were no other instruments to plug into them, harmonica, bass, guitar, and lap steel players used them seamlessly for their performances. They were even used as PA systems for vocals because there were none available.
All Changed With The Rock And Roll Revolution
One of Leo Fender’s amplifiers reached the hands of a drummer on the other side of the world. He sold cymbals and other drumming supplies in a small shop in London. His regular customers included Pete Townshend (The Who) and Ritchie Blackmore (Deep Purple). In those days, amplifiers from the USA were too expensive, and although they sounded great, they didn’t have the sound they were looking for.
To create a cheaper version of the Bassman, Jim Marshall hired some EMI apprentices and a Pan American Airways engineer. For transport and weight reasons, he decided to cut off the head of the amp so that it could be transported separately. Besides using four 10″ speakers, he also used four 12″ Celestion speakers. The rock and roll revolution began with a US engineer, a British drummer, and an airline employee. Until then, everyone used the same amps, but from the sixties onwards, the story would change dramatically, and guitar players would finally get that sweet overdriven distortion they wanted. The sound of Marshall would not exist without Fender, but Marshall would not exist without Fender.
If you plug your instrument into the wrong amplifier, what happens?
Is there any immediate consequence when you plug your guitar into a bass amp, and vice versa? We immediately think of Marty McFly’s scene blowing up Dr. Emmet Brown’s huge amp. Well, not quite.
The Effects of Plugging A Guitar Into A Bass Amp
The best-case scenario would be this. The most reliable bass amp is typically sturdier and has bigger transformers, bigger speakers, and fewer bells and whistles than a typical guitar amplifier. It is doubtful that you will blow up your guitar, but you might find that it sounds dull or that some frequencies are missing. There aren’t as many tone-shifting abilities as there are, so it’s not as important to break it as you might think. It was plugging guitar into a bass amp that I learned how to play and when we did all that down-tuning and playing with massive distortion during the Nu-Metal revolution, bass amps helped.
A bass can be plugged into a guitar amplifier
For starters, if you have a small amp and an active bass, this can be a disaster. The circuit board and the speaker of guitar amps aren’t designed to handle low frequencies well. You might blow the speaker and the amp. However, you can get some amazing sounds when you plug a passive bass into a big guitar amplifier. Motorhead created an iconic style of playing a Rickenbacker with a pick through a distorted Marshall amp. In the long run, the vibration of low frequencies might damage soldering. To put it another way, I would not recommend plugging a bass into a guitar amplifier.
What is the difference between a guitar amp and a bass amp?
Amplifier tubes: Let’s talk about them
Now that you know which path brought us here, let’s talk about tubes. One of the main differences between bass and guitar amps is that they sound different; they are voiced differently. A lot of it has to do with the tubes used. Here are a couple of things you need to know:
Tubes for preamplifiers
The pre-amplification stage is where all the magic happens; especially nowadays when playing a valve amplifier at a high volume in a live venue is almost utopian. The most common preamp tube found in any valve-driven gear is the 12AX7/ECC83. The 12AX7 is the US name and the Ecc83 is the European name, however, they are both very similar. These preamp valves are very easy to overdrive, which makes them ideal for guitar amps and tube preamps. The 12AT7 and ECC81 preamp tubes are slightly different in the sense that they generate less overdrive, leading to a cleaner sound at higher volumes. Many bass amps utilize these tubes in the preamp circuit for clarity and punch.
Tubes for power amplifiers
In a valve amp, power amp tubes generate volume as the second component. Depending on the amount and type of tubes, the resulting wattage and sound of the amplifier will differ quite a lot. Let’s look at the most common choices from the manufacturer.
- The 6V6GT/7408 tubes are commonly found in amplifiers powered between 15 and 35 watts. With approximately 7.5 watts of power each, they are responsible for the iconic sound of VOX amps (think The Beatles and U2) as well as smaller Fender models like the Princeton and Deluxe Reverb. These tubes are known for their easy overdrive, making it possible to achieve that beloved crunchy sound by cranking up a 20-watt amp. However, they are not typically used in bass amps due to their lower wattage – using multiple tubes would be necessary to reach the desired power output.
- 6L6/5881 & EL34 – They were the valves used to power most Fender amps, and they remain the same to this day. The Bassman is still powered by 6L6s. Marshall used WWII US Army leftover 5881s to create the JTM45, which is approximately 25 watts per tube. “The Marshall sound” or “the brown sound” is the result of using EL34 tubes, which are different types of power tubes with the same wattage, but a very different sound.
- KT88/6550 – This is entering almost exclusively bass-amp territory. There are very few guitar players who play through these tubes and almost every big bass amplifier company employs them. The legendary Ampeg Ampeg SVT amps use 6550s to demolish walls with notes. In terms of power, they are slightly more powerful than 6L6s and 5881s.
In terms of amplified instrument sounds, valves are at the top of the list. Although capacitors remain the benchmark for high-end equipment, transistors have long replaced them in more affordable models due to their weight and price. In capacitor land, the distinction is in the voicing of the preamp section, not the components.
What’s the difference between a guitar amp and a bass amp speaker?
An amplifier’s sound is also greatly affected by its speakers. 10″ and 15″ speakers might be very common in bass amplifiers. This is because these speaker sizes are better at translating lower frequencies into the air. In contrast, most guitar amplifiers use 12″ speakers (this was Jim Marshall’s big discovery) because they are more capable of handling mid- and high-frequency sounds. However, when you want more low end, going for 10″ and 15″ speakers can help you get there and vice versa with 12″ speakers. Plugging a guitar into a 15″ speaker and trying to get defined mids and highs from it is almost impossible. Similarly, getting real low end from a 12″ speaker is challenging.
How Come Bass Amplifiers Are Louder Than Guitar Amplifiers?
Bass amplifiers usually generate more volume than guitar amplifiers because the frequencies have more competition. As a result, guitars are tuned to a frequency very close to the human voice. This meant that our ears were specifically tuned to hear that frequency above all others; it was a matter of survival in the past. Conversely, a musician’s friend bass amp needs to push the lower end forward so that it competes with the drum kick (or complements it in the best-case scenario). In my punk band as a teenager, I had a huge argument over the wattage of the amplifiers and shouted at the bass player that he was trying to get all the attention for purchasing a 500-watt amp. The Marshall JCM900 was just as audible in the mix as my 100-watt Marshall JCM900. We laugh about it (he still reminds me of how big a fuss I caused).
Since the instrument also makes a big difference, there is no rule about it, but for a bass marshall ampto be up to the task in volume, it usually has to be twice as large as a guitar amp in watts. Remember that in order to “move” a 15” speaker, more power is required than with a 12”, so the power amplifier section needs to be more powerful.
Features of Guitar Amplifiers vs Bass Amplifiers
Here’s another area where guitar and bass amps differ drastically. Let’s look at some history to understand why this is so. Guitar players needed to get distorted tones at lower volumes in the mid-seventies and early eighties. A bassman or a JTM45 would distort if you pushed the valves and played loud, but this became problematic in some venues and guitar players also needed more gain. Marshall came up with the idea of adding a master volume so you could push the valves separately. Early models of the JCM800 had a preamp knob and a master knob. The first knob pushed the 12ax7s creating natural overdrive without adding volume, while the master knob handled the mighty EL34s. If you set the master low and the preamp high, you’ll be able to distort your amp without killing anyone in the first row.
Slash may be the most famous user of this amp. Still, it has also been used by Eric Clapton, Billy Corgan (Smashing Pumpkins), Tom Morello (Rage Against the Machine/Audioslave), Mike Mushok (Staind), Scott Ian (Anthrax), Joey Santiago (The Pixies), Johnny Ramone, and Zakk Wylde (Ozzy Osborne/Black Label Society), among many others. It was released in 1981 and is still manufactured today in England. In bands like Nirvana, Alice in Chains, Jane’s Addiction, and so forth, guitar players needed clean for the verses and distortion for the choruses/leads.
As a result, Jim Marshall created a new amplifier that could switch between distorted and clean channels, bypassing pure tube overdrive in favor of transistor-driven distortion. Combined with a footswitch, the JCM900 was launched in the 1980s (JCM800 in the 80s, JCM900 in the 1990s). This became a standard feature in most modern guitar amplifiers and the idea behind the creation and commercialization of many of the guitar pedals we see today. Now that you know where it comes from, let’s take a look at the features you can expect:
Common features of guitar amplifiers
Possibly the oldest addition to the guitar amplifier was reverb. A reverb effect is used to simulate a natural echo in a large room. It is often associated with Fender amps, as well as surf guitar. Quentin Tarantino’s Pulp Fiction movie title track probably reminded you of it. Distortion differs from natural overdrive not only in how it’s created, but also in how it sounds. Dual-channel amps are very common these days. It was thought to be a revolution in the early 2000s, but now it is mostly hated by purists and is mostly found in practice and small amplifiers.
Common features of bass amplifiers
Modern amplifiers typically come with an impedance switch, which responds to the fact that active basses are much more common than active guitars. By plugging in either a passive bass or an active bass, you will be able to accommodate one or the other seamlessly. They are usually marked active/passive. It is rare for people to plug a guitar into a direct line to a mixer, but for bass players, it is much more common. With an XLR output, you don’t need to use a microphone in front of the speaker and can send a preamplified signal directly to the mixer. This is very handy when playing live or in the studio. There are some bass amps with an onboard limiter to prevent overloading the circuit and also to prevent an excessive amount of bass from reaching the speaker. They usually come with colored LEDs (green and red) to indicate when it kicks in. Compared to guitar amps, bass amps are way more straightforward.
Words of wisdom
Many people wonder what the difference between guitar amps and bass amps is, and the answer lies in the concept and the voicing. Different materials produce different sounds and varying valves, speakers, and features can take you to different places. As a result, the biggest leaps in art often come from breaking the rules. Now that you know the possible damage, origins, meanings, and concepts, you can take your sound to new levels.
You can achieve anything if you are bold and wise.
I wish you a happy (amplified) playing!