Hafler HA75-DAC User Manual

HA75-DAC

User Guide

USB Digital Audio Converter
& Headphone Amp

Haer is a division of Radial Engineering Ltd.
1588 Kebet Way, Port Coquitlam
BC, Canada V3C 5M5
[phone] info@haer.com

www.haer.com

Table of Contents Page

Overview ................................................................................ 1

Features ..............................................................................2-3

Connect ...............................................................................4-5

Testing Your Connections ....................................................... 6

Source Select Switch ............................................................. 6

Using the Headphone Load .................................................... 7

Using the Focus Control ......................................................... 8

Using the Vox Control ............................................................. 9

Warranty .................................................................Back Cover

Thank you for purchasing the Haer HA75-DAC headphone

amp and digital audio converter. This warm sounding tube

headphone amplier is designed to be easy to use while

providing the user with many customizable features to further
enhance the listening experience. This manual has been written
in order to provide you with all of the details so that you may take

full advantage of these extra features. As such, we ask that you
take a few minutes to read it. If you nd yourself looking for more
information, please visit the HA75-DAC FAQ page on the Haer

web site. This is where we post answers to questions from users

that are often helpful. Then, if you are still missing something,
feel free to send us an email at info@haer.com and we will do

our best to reply in short order.

HA75-DAC 'TUBE HEAD' HEADPHONE AMP

USER GUIDE

HA75-DAC HEADPHONE AMP

Haer

1

WARNING

HIGH POWER AMPLIFIER

The powerful amplier inside the HA75-DAC is designed to
accommodate all types of headphones from 8Ω to 400Ω. As we have
no way of determining the headphone impedance, the amplier is

very loud. Exposure to high sound pressure levels for an extended
period of time can cause irreparable ear damage. Please consult
your local health authority to ensure you do not expose yourself
beyond recommended limits. Radial shall not be held responsible

for using the HA75-DAC without due care or beyond recommended

legal limits imposed by your local government. Use by children is not
recommended and therefore must be carefully monitored by parents
or guardians.

CAUTION

HIGH VOLTAGE

There are high voltages inside the HA75-DAC. Before opening the unit

- It must be unplugged from the power supply and allowed to discharge

for at least 30 minutes. Touching the wrong place can cause a severe

shock. High voltages present at the tube socket will remain present

for some time after switching the HA75-DAC off. There are no user
serviceable parts inside. Only use indoors in a dry space. Do not open
unless you are a qualied technician or have experience with tubes.

OVERVIEW

The Haer HA75-DAC is a digital audio converter and tube-based

headphone amp with a number of innovative features that allow users to

tailor the listening experience to their liking. At the heart of the HA75-DAC
is a 12AX7 tube utilized for signal amplication. Tubes are preferred by
audio enthusiasts and recording engineers alike for their smooth, natural
sound, and the HA75-DAC exploits these characteristics to produce a

detailed and warm sounding output that has won the praise of many
experts in both the recording and mastering industries.

The HA75-DAC also employs high quality digital-to-analog converters

that allow connection over USB from digital audio sources such as a

laptop computer. Sample rates of up to 24bit/192khz are supported,

routing the signal through the tube-based analog circuitry. This approach
combines the best of both the digital and analog worlds in one powerful

and exible headphone amplier.

HA75-DAC HEADPHONE AMP

Haer

1. ON: Activates the HA75-DAC. It is recommended to warm up the

tube for 15 minutes to achieve thermal stability.

2. SELECT: From the front panel you can select between the analog
and the digital USB inputs.

3. FOCUS: Active matrix lets you control the width of the stereo image

to replicate listening to loudspeakers in a room.

4. GAIN: Used to adjust the volume for headphones.

5. VOX: Three position switch lets you enhance low frequencies to

suit the listening level and program material.

6. LOAD IMPEDANCE SELECTOR: Allows you to change the output

impedance to optimize performance with your headphones.

7. HEADPHONE OUTPUTS: Dual ¼” TRS outputs to enjoy the

listening experience with a friend. For best results use two matched
headphones as the impedance determines the loudness.

2

FEATURES

2 3 4 5 6 71

VOX Switch
A - Bass enhancer
Ø - Bypass / O
B - Loudness