If you want to make your combo amp louder, then you may be wondering if you can use it as a head unit, and connect to a speaker. Or you may want to turn your combo amp into a head unit because you prefer how it sounds to other head units you’ve tried.
Whatever your reason, I’ll go through the best way to use your combo amplifier as a head, in this complete guide. So let’s get started!
The Quick Answer
You can use a combo amp as a head unit, or as a cabinet in a stack setup by connecting it to the external speaker or head unit that you’re trying to use, respectively.
using a combo amp as a head
- You can use the line-out speaker jack on your combo amp to connect a speaker cable directly from your combo to the external cabinet.
- You can disconnect the speaker and head parts of your combo, and solder a jack onto the head unit cable to connect it an external cabinet.
using a combo as a speaker (cabinet)
- If your combo has a 1/4″ cable connecting your head and speaker unit on the back. Disconnect the cable from the head, and plug it into the external head.
- If there is no cable, then you’ll need to disconnect the speaker and head unit of your combo, solder a jack onto the speaker unit cable, and connect it to an external head unit.
Combo vs Stack Amplifiers
First things first, let’s be clear about what were talking about when we’re discussing amp heads, combo amps and speakers.
There are two main types of amp setups you can use with an electric guitar.
- Combo amplifier
- Stack amplifier
To properly amplifier the sound of your electric guitar, you need two things. The first, is the amp part, which is what dictates your guitar’s tone, and the amount of power behind it. The second, is a passive speaker, which plays the signal from the amplifier.
Combo amplifiers have both elements all-in-one. So they consist of the amp part, and the speaker. Stack amplifiers consist of a head unit, which is the amp part, and a cabinet, which is the speaker.
When using your combo as a head or cab, you’re essentially using it to create a stack setup.
It’s really important to be clear about impedance and power rating matching here so if you don’t know what I’m talking about, please check out my article on combos vs stacks to avoid damaging your equipment.
How to Use a Combo as a Head Unit
Since a combo amp consists of both the speaker and the amp, a lot of people want to use it as a head unit, in a stack amp style setup.
So how do you actually do this?
If your combo amp has an external speaker jack, then you’ll simply be able to connect your combo and the speaker together (option 1).
Or if it doesn’t have a jack, then this involves either disconnecting the speaker element of your combo amp, and connecting it to a passive speaker (option 2).
Option 1: Using a Line-Out Speaker Jack
This is the easiest and quickest method. If your amp has a line-out jack for speakers, then you can connect the combo amp and cabinet together. Then you can use your combo amp, in the same way as you would with a head unit, to control the tone. Don’t use your guitar cable for this.
In most cases you’ll be using a 1/4″ cable to do this.
You’ll need to be able to check the resistance ratings of both your amp and speaker to make sure they match though.
option 2: disconnecting your combo’s head and cabinet
If your combo amp doesn’t have a line-out for a speaker, then things get a bit more complicated.
You’ll need to know what you’re doing if you take this option, and in a lot of cases, it’s just easier to buy a head unit. Disconnecting your combo’s speaker and amp isn’t a quick fix, and you won’t be able to reconnect them easily.
But, if you decide it’s what you want to do, then here’s a quick guide.
Make sure your amp is completely disconnected from your mains, or any other supply before doing this.
- Remove the back of your amp and locate the wire that connects your speaker to the amp.
- Cut this wire using pliers and strip it, and cover it with a jack.
- Then you’ll need to connect a jack to the amp wire.
- Use a speaker lead to connect the amp jack to the cabinet.
How to Use a Combo as a Cabinet
So what about if you want to use your combo amp as a cabinet, instead of a head. This means that you’ll already have your head unit, and you’ll want to use your combo simply as a speaker.
There are a couple of options.
Some combo amps, if you look at the back, have a cable on the outside that connects the amp part of the combo, to the cabinet part. If your amp looks like this, then you can simply take out the end of the cable that’s connected to the head part of your combo, and plug it into the separate head unit. If the cable isn’t long enough then you can use 1/4″ cable adapter to lengthen the cable.
Again, make sure you check that the impedance (resistance) matches.
If your combo doesn’t have a cable connecting the head and speaker part, then you’ll have to follow the steps I described earlier to disconnect the head and speaker on your combo and then solder a speaker jack onto the speaker cable on your combo, and connect it to the separate head unit that you’re trying to use.