How many channels do I need in my guitar amp?
At least two.
Next to circuit type (tube or solid state/digital), I would argue that the number of channels is one of the most important specs to pay attention to when buying a guitar amp. I'd recommend having at least two switchable channels, one for your clean signal and one for your distortion/dirty signal.

We should first go over a quick definition of what channels in an amplifier actually are and how you use them.
Simply put, channels in a guitar amp have a different set of parameters and preamp controls that are separate from one another. They also typically have different types of gain levels (distortion) set up.
Read more: Best guitar amps overall
- Low gain for a clean channel
- High gain for a dirty channel
This means that you can switch between these channels depending on what sound you're looking for.
Other more advanced guitar amps might have three or even four channels:
- Clean tone
- Subtle distortion
- Heavy distortion
Typically channels will at least have volume controls, like the image below.

An example of two different controls for two channels. The clean channel and dirty (gain) channel.
Some guitar amps have individual EQ bands for each channel, like the Mesa/Boogie Triple Rectifier pictured below, with a gain, master volume, bass, mids, treble, and presence dials for all three channels.

More advanced amplifiers will have a full spectrum of control, including a three-band EQ for all their channels.
When you break up your sounds between channels, it means you can set one channel for a particular level/EQ, and a second channel for a different level/EQ.
Then, instead of having to fool with knobs to make that change, you simply switch channels at the touch of a button, which can usually be done with the amp's footswitch.
But how many channels do you need for a guitar amp?

Two channels in a guitar amp is pretty standard, especially a tube amp, but everyone's situation is different.
How many channels do you need?
Everybody's situation is different, but I'd recommend having at least two channels in your guitar amp, leaving one for your clean signal and one for your distorted signal, just like I recommended in the opening paragraph.
If you use different levels or types of distortion, it might be worthwhile to consider an amp with three or four channels.
Generally, the more channels you add, the more expensive the amplifier.
Keep in mind, this all depends heavily on your situation, and the versatility you need to have at your disposal. It may or may not make sense for you invest in an amp that can deliver more flexibility.
What about distortion pedals?
While distortion pedals can work, I typically recommend that, if at all possible, you get your distortion directly from your amplifier. This is almost always a superior option, assuming you have a decent amp with a dedicated dirty (distortion) channel.
Here's some more info on that if you want to read further.
Read more: Should I use a pedal or amp for distortion?

There are some awesome distortion pedals out there, but I typically prefer/recommend a high-quality amp-based distortion.
Channel differences between tube amps and solid state amps
Another variable to consider is whether you get a tube or solid state amp. Tube amps are usually nicer and sound better, because they use actual vacuum tubes and analog circuits.
However, this makes it more difficult to manufacturer multiple channels, which makes the amp more expensive to produce. This is why you typically don't see more than two or three channels in tube amplifiers.
On the other hand, solid state amps are easier to add more channels to.

A lot of solid state amps, like the popular Boss Katana 50, have multiple amp "models" or styles of gain. In this photo the amp type selection is all the way to the left with five options.
Solid state, modeling amps, and presets
Seeing four or five channels in a solid state amp is not unusual. A lot of them even have digital presets, which can sometimes number in the hundreds, giving you more "channels" to work with than you would ever need.
These are usually called modeling amps.
How you feel about tube/solid state/modeling amps will have a lot to say about how many channels you end up with. In most cases, three or four channels is enough, especially if you don't want your amp to double as an effects processor. The decision is yours.
Footswitch consideration
Whatever number of channels you go with, just make sure you get an amp that has, or at least supports, a footswitch.
You should be able to switch with a button at your feet rather than having to do so by hand on the amp's control panel.
A lot of amps come with a footswitch, though plenty are sold separately.
It'll just depend on the amp.
Conclusion
To conclude, I'd recommend at least two channels, perhaps more if you want to use multiple types, or levels, of distortion. If you're considering a solid state amp, or you want to get an amp that can double as an effects processor, you could probably get a lot more channels and/or presets for your money.
Your situation is unique, so just take the information I've given you here and decide what works best for you.
Questions can go in the comments section and I'll respond.
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Written by Bobby Kittleberger on Amps & Reviews
Written by Bobby Kittleberger on Amps & Roundups
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