QuantAsylum QA401 User
’s
Manual
Page
6
Legal
This document and the associated computer codes, hardware design and hardware configuration files
are copyright © 2011 - 2019 by QuantAsylum USA LLC. All rights are reserved. You may share the
associated documents in PDF format freely. The EXE programs and code in the developer section is for
use only with QA products. The hardware and software designs are protected and the property of
QuantAsylum USA LLC.
In the Box
Your new analyzer should contain the following:
•
QA401 Audio Analyzer
•
Certain product variants may contain cables. But as a general rule
, we’re moving towards NOT
shipping common cables with products any longer.
Installation software, this manual, and application notes for the analyzer are available on the web at
http://www.QuantAsylum.com. Inside the box you will find a card with a QR code that will take you to
our web page with the latest information on the product.
Important Things to Know
Ground Reference
The analyzer PC interface will share a ground with the PC. The audio inputs and outputs, however, are
isolated from the PC. This isolation is limited to 50V. Do not connect the QA401 to a product that has its
ground reference more than +/-50V from the PC ground.
BNC Input Voltages
The AC input to the analyzer should never exceed 56Vpp (single ended) or 28Vpp (differential). The DC
limits are lower. DC voltages above +/- 6V with the attenuator disengaged may permanently degrade
the performance of the device. In general, we recommend a DC limit of +/-5V regardless of attenuator
setting. If you need to measure power supply noise, see the section in the manual on how to safely do
so.
BNC Output Voltages
The BNC output connectors have a 47 ohm limiting resistor and thus have minimal protection. If you
accidentally connect a signal of more than few volts to the outputs, you may damage the output stage.
QA401 Output Voltage Offsets, Clicks and Pops
The QA401 output voltages will nominally have an offset of 1-2 mV. If you wish, you can trim those
offsets to microvolt levels through the Settings->Options->Other->Trim menu. However, be aware that
certain operations on the QA401 can generate clicks and pops and also modify offsets. This is especially
true when using external programs to control the QA401.
