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Amp have multiple inputs to distinguish high impedance input and low impedance input.

While multi channel amp means that the amp can play sound to multiple speakers – usually in a surround sound system or speakers with left and right output.

Amp channels and inputs are super confusing. I remember feeling stupid and lost when I first started reading about amp channels and inputs. 

I found it very difficult to find online articles or videos explaining about this topic. This article is my attempt to simplify amp inputs, channels and impedances. Hopefully this helps you out in your guitar journey.

I will be covering below topics:

  1. Why amp have multiple inputs (High Vs Low)
  2. High Impedance Vs Low Impedance
  3. Why amp have multiple channels
  4. Are more channels and inputs better for an amp?
  5. Can you connect multiple guitars to 1 amp?

Why Does An Amp Have Multiple Inputs (High Vs Low)?

An amp has multiple inputs to allow you to connect audio sources correctly. High impedance instrument connects to the high input whereas a low impedance instrument connects to the low input.

High input and low input on amp doesn’t mean volume. Most people understand it wrongly. You don’t connect your guitar to high input for higher volume or connect to low input for lower volume.

Most audio sources like guitars, mic and keyboards operate with different signal strength. Based on the signal strength, you need to connect your guitar to the correct input on the amp.

Using the incorrect input can produce low quality, noisy sound or even damage the amp. Most guitar signals operate with high impedance, which means you should connect to the high input on your amp.

Connecting a high impedance source into a low impedance input will result in a dull, mellow and noisy sound – the high frequency notes are filtered out. 

This is why if you connect your guitar to the low input, you will get a sound with lower quality and volume.

In the worst scenario, connecting a high impedance source into low impedance input can even break the receiving instrument (like an audio mixer). 

However, this worst scenario of breaking will not happen to your guitar amp. The high input and low input on guitar amps do not vary by much.

Plugging your guitar incorrectly into the low input will just give lower volume and dull tone. 

But I urge you to read the manual of your amp, they should explain what the inputs mean. Some amps may work differently.

Let’s talk more about impedance now – what the hell even is that?

guitar amp high low input

Guitar amp high and low input

High Impedance Vs Low Impedance

On audio equipment, Impedance is the resistance to electricity (audio signals). This is the simplest explanation without getting into too much science. 

High impedance equipment has higher resistance and can take in more power (voltage). Whereas low impedance equipment has lower resistance and cannot accept too much power (voltage).

Audio equipment with high impedance is better at playing high quality audio – clearer sound, better bass and higher frequency ranges. Expensive headphones and electric guitars usually operate at high impedance.

Audio equipment with low impedance cannot take in too much power. They cannot produce high quality sound like high impedance equipment but they are easily powered and mobile.

You don’t need any special amp or sound card to power low impedance equipment. It’s usually plug and play like your regular earphones and mobile phones. 

The most important thing is impedance matching (between the input and output). If your instrument (the output) has high impedance, then connect it to a player or mixer (the input) with high impedance.

You will get the best sound quality this way.

Why Does An Amp Have Multiple Channels?

A guitar amp with multiple channels allows you to switch the tone of the guitar without setting up additional pedals – typically 1 channel for clean and another channel for distortion. 

With a multi channel amp that provides clean and distortion sound, you won’t need to buy additional pedals for distortion – it’s already built into your amp!

For beginners: Multi channel amps replace the needs of additional pedals. The effects you need from external pedals are built into your amps – allowing you to have different effects without setting up any pedals or pedal boards. 

Multi channel amps are great if you need to perform on stage. The setups you have are cleaner, there will be less cables and battery issues that you would have to worry about when using external pedals and single channel amps.

However, cheaper multi channel amps often only provide controls that impact all the channels, if you need individual channel adjustments you need to go for more expensive ones.

multi channel guitar amp

Multi channel guitar amp

Are More Channels & Inputs Better For Amp?

Amp with more channels and inputs are not necessarily better. Get the amp that best suits your needs and playing.

This is especially true for amp channels. Multi channel amps are usually more expensive and have more buttons than single channel amps. 

 If you are a beginner and don’t perform regularly, a single channel amp is better than multi channel. They are simpler and you can always buy external pedals to get effects.

If you are an advanced guitarist that needs to perform, then a multi channel amp is better than a single. You can have more effects without worrying about external pedals, batteries and cables.

As for amp inputs, the number of inputs doesn’t really matter in most situations. Just remember to plugin your high impedance guitar into the high amp input to get the best sound quality.

Can You Connect Multiple Guitars To An Amp?

You can connect 2 guitars into 1 amp by using a Y splitter, audio mixer or an amp with multi channels (and independent controls). 

Each of the methods vary in price and quality. Based on your needs and budget, you should choose one. Though, I personally think the best way is to buy another amp for that additional guitar (even if it’s a cheaper one).

Here are your options to connect multiple guitars into a single amp:


1. Using Y Splitter

With Y splitter, you connect the 2 guitars into the splitter and connect the splitter into your amp. 

This is the cheapest and easiest way but the sound quality is bad and you cannot distinguish which guitar the sound is coming from.


2. Using a Mixer

Connect 2 guitars into a mixer with multi channel and connect the mixer into your amp.

A mixer with a multi channel typically costs about $100 – which is about the same as a regular amp. 

 It’s possible to connect 2 guitars into 1 amp using a mixer with multi channel but I highly recommend you get a separate amp with the budget.


3. Using multi channel acoustic amp

Connect 2 guitars into an acoustic amp that has a multi channel. This amp should have independent channels with separate controls.

Otherwise, the result won’t be good (the same as using cheap Y Splitter)

Many acoustic amps have 2 inputs – 1 for guitar and another for vocal. You can use this acoustic amp to power 2 electric guitars.

It should work well and you have independent controls. But don’t expect any distortion effects from the amp. Though, you can still use external pedals to achieve the dirty effects you want. 

Acoustic amp with 2 independent channels

Acoustic amp with 2 independent channels

Ifandi S.

About Ifandi S.

Ifandi started Strumming Bars to answer all the questions of a guitarist. As a self-learned guitarist, he remembered how frustrating it was to not find answers to his many questions in the journey. With Strumming Bars, that's no longer the case!

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