Welcome to the Sounds From The Apartment blog once again! Today, we’ll discuss about the Analogue Inputs on an audio interface as part of our series “What is an Audio Interface

Although an audio interface might have a lot of buttons and lights (or not) on it, and you can find a summary of what we will be discussing on these series on the Understanding An Audio Interface article, the Analogue Inputs are the first line components that will get our the audio signal processed! So let’s find out a bit more about them.

Sounds From The Apartment Facebook White Banner

Analogue Inputs

Every device that can receive audio has some kind of input. Starting from simple everyday consumer devices like our smartphones. They have an on board microphone which we feed audio into it (by talking usually) and then that audio is converted and transmitted to the other end only to be converted back into an audible signal for the other party to listen to.

Usually these microphones and speakers don’t have much settings to fiddle with apart from volume, and that is because realistically you wouldn’t need anything else to make a simple call.

Moving onto professional audio equipment, every device that can receive audio, such as an analogue or digital mixing desk, a portable handheld recorder, an audio interface, they all have an Input Section for each input. The Input Section allows us to control how the Analogue Input will behave and manage the incoming audio.

The Input Section for audio interfaces will be a separate article, as it contains a lot of controls we need to discuss separately, including the Preamp, but to give you a quick idea, it is a resemblance of an analogue mixer desk input section in a digital way within our interface, and therefore our computer. Some interfaces offer buttons for the Input Section controls, some allow us to digitally control them, and some have some controlled by buttons and some digitally.

Sounds From The Apartment Instagram White Banner

But let’s don’t jump subjects. Let’s move back to the Analogue Inputs.
The most common question I am asked by most people is:

How many inputs should my audio interface have?

And the answer is always “I don’t know!“.

See, the amount of inputs your interface should have is the amount of inputs that will cover YOUR (yes, that’s in capitals, bold, italic and underlined – probably emphasised more than enough!) needs!

And also, that applies to the type of Analogue Inputs too. If you go back to the Audio Cables Basics article and refresh the knowledge of cables, you will remember that we use different types of plugs on these cables. And since these cables are carrying a signal that needs to get somewhere, we need the same type of plug on the input.

Let’s see the types of inputs we have available and then answer the one million pounds question.

XLR Inputs

The XLR Input on the Steinberg UR12 Audio Interface
The XLR Input on the Steinberg UR12 Audio Interface

The XLR Inputs exist to accommodate any Microphone Level Signal comes in their way and have a Preamp at the back of them so they can amplify the incoming signal. You can plug into these any microphone or device that provides a microphone or balanced level output, and they can also provide Phantom Power (48V) to the connected device!

TRS Inputs

The TRS Input on the Steinberg UR12 Audio Interface
The TRS Input on the Steinberg UR12 Audio Interface

The TRS Inputs essentially handle Line Level Signal and they are not using preamps at the back of them as the Line signal is significantly greater than the Microphone Level signal. The TRS Inputs can also be Hi-Z.

We are going to discuss further about Hi-Z on the Input Section article, and later on, we will also look into the Microphone and Line Level Signals!

Combo Inputs

The Combo Input on the Steinberg AXR4T Audio Interface
The Combo Input on the Steinberg AXR4T Audio Interface

The Combo inputs (as you probably can tell from the name) combine the best of both the XLR and TRS worlds. They can receive both these plugs, however internally they have separate connectors. The XLR connectors will guide the signal to the preamp, but the Line ones will have the signal bypass it. Same with Phantom Power, it can run through the XLR connectors but not on the TRS ones.

Practically, depending on what type of plug or signal you connect to the Combo Inputs, you need to respectively treat them as if it was an XLR or TRS input. They maintain the same characteristics when handling signal but 1 input can facilitate 2 types of audio cables. It’s like shampoo on a 2-for-1 offer!

Sounds From The Apartment YouTube White Banner

Ok, but how many inputs should my audio interface have then?

Ah! The flaming question! Like I mentioned before it has to do with your needs.

A) If you are planning on using the preamps of the audio interface you will need one with XLR or Combo Inputs. That could be in a studio setup, although it is quite commonly found in Home Studios.

B) If you are planning to use external preamps, you will need TRS Inputs on your interface. In case you are wondering, these setups are typically ones in studios that have a live room for tracking and have a mixing desk which gives them the ability to route each of its channels to the Audio Interface Inputs, simultaneously, so they can record on their computer. And since they are using the preamps of the mixing desk they don’t need to have any on the audio interface.

Now the number is dependant by the above factors too. If you were thinking about scenario B, typically a mixing desk in a studio environment has no less than 16 inputs. So you should aim at an interface with the same amount of inputs. And outputs. so your total I/O (Inputs/Outputs) will probably be dictated by the mixing desk you are going to have installed in there.

Assuming you are going for scenario A now. You need to think clever here. The first question you need to ask yourself is:

What am I going to be recording?”

Is it going to be just vocals?
Or maybe singer/songwriter stuff with guitar and vocals?
Am I going to record guitar cabinets?
Am I planning on using techniques that require more than 2 microphones (and therefore inputs)?
What if I wanted to record 2 singer/songwriters at the same time, both on vocals and their guitars?
And what if one of these singer/songwriters wants to also use a stereo keyboard?
Do I want to record drums in my place?
Or maybe a full band?

So as you can tell, these answers, depending on what you will be recording will dictate the number of inputs you need. For example, you need at least 8 inputs if you are going to be recording drums with close mixing! Maybe then expand to 16 inputs if you want to be recording full bands while all perform together; then again the minimum you can have for just vocals or just one singer/songwriter is 2. All the other scenarios are somewhere in between. You just need to decide what you are going to be recording in your place and then count the number of inputs you need.

Sounds From The Apartment Patreon White Banner

The second question you need then to ask yourself is:

How much am I willing to pay for the inputs I want?”

There is a vast amount of audio interfaces out there. And the major decision issue occurs when you realise you can find interfaces with 2 inputs at £100 but also at £1000. This happens because the latter usually have a much better quality of electronics and components installed, and also might be giving the user more options when it comes to connectivity and expandability and that can be a game-changer when choosing an audio interface. Interfaces with more inputs follow the same principles when it comes to price.

This being a personal question and being dependant on the size of your budget, you can only decide if you want to go for a cheaper interface and invest more money on other aspects of your studio or go full in on the audio interface.

Now you know…

How the inputs of your audio interface can affect your decision-making game. My advice is not to take this lightly and think well before buying your audio interface. A good purchase and spending a bit more will potentially save you money in the future when you will want to expand your studio.

For example, if you go for 2 inputs in the end, with £100 extra, you might get an interface with better preamps but also an ADAT Input (more on this on future articles). This means you could add another 8 channels to your 2 input interface, via the digital ADAT pipeline, without having to sell it and buy a new one! Think smart!

Go now you little audio geek! Buy an audio interface with the inputs you really want and maximise your productivity!

If you enjoyed this article, please give us a little boost on Patreon so we can produce more articles like this! If you can’t donate, sharing our page is always a good alternative!

Let us know with your comments for any feedback so we can improve our content and follow our Instagram and Facebook pages!

Sounds From The Apartment Spotify White Banner

Don’t forget to grab your FREE tips on how to manage your home studio in a better way, by clicking here! Or if videos are your thing, subscribe to our YouTube channel!

Leave a comment with the interface you are thinking of buying and why and we’ll catch up next week!