Holo Audio Azure Headphone Amplifier


“A fine standalone headphone amplifier”

SKU HOL-AZ Category

The Holo Audio Azure is just an amplifier. So by function, it’s nothing particularly special at first glance – just a headphone amp and pre-amplifier?

Not so, The key for Azure is the fully discrete amplifier modules – there are 8 of them inside the Azure.

There are 4 channels to create a fully balanced amp, and each channel has 2 discrete amplifiers, one for buffering and one to amplify. Jeff Zhu of Holo Audio has dedicated a tremendous amount of time to develop the Azure and has researched a way to get more detail and natural sound from a discrete transistor based amplifier. This is more comparable to tube sound, although with better detail retrieval.

Holo Audio have chosen specific transistors that have a high performance thermal character. So with a large amount of these transistors they have made an amplifier that performs extremely well by design.

With the Azure’s 8 discrete amp modules, each module has about 50 transistors per module. This ensures superior linearity. In a tube amp, the more tubes improve linearity, but how many tubes are considered reasonable? The amount of transistors in the Azure is very high compared to many discrete amplifiers on the market.

This is key for its performance, sound signature.

Premium grade components have been carefully chosen to deliver the best possible sound signature that Holo Audio is well known for. For an example, Mundorf Capacitors are used and also a quality O-Type transformer is utilised for optimum audio performance and of course it is effectively shielded from surrounding components. Each part of this circuit design has been extensively thought through and specific components paired for optimal audio performance.

The Azure’s 8 modules have a total about 400 transistors. This renders overall tone and sound stage to be suitably impressive.


Analogue Input:

Single Ended Input x1
Largest Value 12Vpp
Impedance 3.9 Kohm

Balanced Input x1
Largest Value 24Vpp
Impedance 7.8 Kohm

Analogue Output:

Single Ended Line Output x1
Largest Value 16Vpp
Impedance 33ohm

Balance Line Output x1
Largest Value 32Vpp
Impedance 66ohm

Headphone Single Ended Output x1
Low Resistance Mode – 400mW at 32 ohm load
High Resistance Mode – 180mW at 300 ohm load

Headphone Balanced Output x1
Low Resistance Mode – 1600mW at 32 ohm load