What are Hi-Z, line & instrument Level inputs? – [Answered]

What is a Hi-Z input?

Almost on all of the audio interfaces, you are going to stumble upon the term Hi-Z input. Furthermore, many people might also have recommended you to buy an audio interface that has and supports such input. But, do you know what is a Hi-Z input?


  • Should you care as a musician/artist/producer if your audio interface does not have a Hi-Z input?
  • how does it differs from other inputs such as mic or line level?
  • Difference between a DI input and a Hi-Z input.
  • And much more!

Let’s start with the actual meaning first!

Also Read: Setting a Home Recording Studio – A step by step Guide!

What does Hi-Z mean on an audio interface?

guitar is an example of hi-Z input

The term Hi-Z input is derived from the word high impedance. Let’s have a look at the meaning of a Hi-Z input.

In terms of electronics, Hi-Z input means that the circuit will have a relatively lower current and a higher potential/voltages when compared to regular inputs like mic or line level. Generally, the voltage values of Hi-Z inputs are more than 1000 ohms, whereas other inputs have voltages less than 600 ohms. Such types of inputs are used to record instruments with high impedance and no audio signal amplification.

Higher voltages in the Hi-Z input risk inducing noise as even the slightest of noise can get amplified significantly, so much so that it becomes notable and irritating.

[Also check: How to setup your audio interface with connection diagrams!]

What is a Lo-Z input?

What is a Lo-Z input?

Another term you’ll get to know is line-level input, also known as “Lo-Z” inputs. As the name suggests, these types of inputs work opposite to that of “Hi-Z” inputs.

A “Lo-Z” input” means that the circuit possesses a high current and low voltages. These inputs are purely made for instruments where the courses in the instruments already do pre-amplification. Lo-Z inputs have low noise levels due to less amplification done by the input circuits. For example, MIDI instruments, Studio monitors & condenser microphones.

[Also check: What is direct monitoring in an audio interface]

Why do we need a Hi-Z input?

For recording instruments with a high impedance, we cannot use mic/line level or “Lo-Z” inputs that have low impedances. Doing so will result in an impedance mismatch. In addition, the audio quality will suffer a lot. It may fall out of the audible range or decrease the gain levels of the audio being recorded. In short, recording high impedance instruments with Hi-Z inputs maintain the best possible quality of the audio signal.

Which instruments use a Hi-Z input?

In instruments like guitars where no audio signal amplification is done, a Hi-Z input will come handy in every recording session. Try using a Lo-Z or line-level input for recording a guitar, and you’ll exactly know what I mean. In contrast, we do not use high impedance inputs for MIDI instruments because an inbuilt circuit is already amplifying the audio signal.

In short, if you cannot see any amplification happening in an instrument, it is a powerful sign that you’ll need a Hi-Z input.

[Also check: Best audio interfaces for recording guitars also!]

Is there any difference in quality between different Hi-Z inputs?

The Hi-Z inputs vary from equipment to equipment. However, in the case of an audio interface, it is a highly subjective matter. Also, the difference becomes almost negligible once a DAW comes into action. The DAW can add several layers of filters which can mask the Hi-Z quality.

[Also check: Audio interface setup diagram to connect different studio gears]

Hi-Z inputs vs DI inputs

In simple words, a DI input in a DI box takes a high impedance signal as its input and outputs a balanced low impedance signal. Whereas a Hi-Z input increases the impedance of a regular line-level input so that it becomes suitable to record high impedance instruments.

Learn more here.

What is difference between Hi-Z, line level and Mic level inputs?

There are 4-6 main differences between Hi-Z, line level and a Mic level input:

  • Impedance levels,
  • Type of cables and ports used,
  • Dynamic and gain ranges,
  • Category of instruments,
  • circuit type,
  • noise level variations.

[Also check: Mic vs Line vs Instrument level inputs]


These were my thoughts on the Hi-Z inputs and how they differ from other kinds of inputs like mic/line level or DI inputs.

If you have more to say, I’d love to listen to you.

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