Owner`s manual
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PH: 720.406.8946 service@psaudio.com www.psaudio.com
Quick Start Guide 6
®
Quick Start Guide
©2012 PS Audio Inc. All rights reserved.
Owner’s Reference PerfectWave DAC MKII
audio dependent on your source material and the program you're using. Some programs, like iTunes,
will always resample the audio to the highest sample rate allowed by the driver - in the case of the PWD
it is 192kHz. Use a program like Bit Perfect, Amarra or Pure Music to bypass the iTunes restrictions to get
native sample rate performance.
The PWD will memorize the last setting chosen for the input you are on. So, for instance, if you
choose NATIVE while on input I�S2 and 192kHz for RCA, the SRC will automatically switch to
that setting when you change inputs.
The PWD oers a wide assortment of digital lters. Digital lters are necessary and used in
all modern DACS but few are as sophisticated as those in the PWD. The problems with any
lter, whether it is analog or digital, are the eects they have on the passband (usable audio
frequencies).
Filters leave several types of negative artifacts: group delay, phase and ripple errors. Some
lters minimize phase and group delay errors while others minimize ripple errors. Each error is
minimized at the expense of the other; thus, there is no such thing as a perfect lter and, as with
many things in electronics, each is a tradeo with good and bad points.
The PWD has two basic types of lters with several combinations of the two available. The two
lter types are: Linear Phase and Minimum Phase as well as Recursive Non-Half Band (which
is basically a combination of the rst two). Within these two main lter types (Linear phase and
Minimum) there are several variations to choose from on each lter, including Apodising and Soft
Knee Filters.
From a user perspective, we recommend choosing whichever lter sounds the best to you
without being overly concerned about understanding these extraordinarily complicated subjects.
Our favorite on the PS system is Minimum Phase Apodising “MP Apod” on the touch screen.
A brief explanation of each lter type appears below.
Linear Phase and Minimum Phase lters
Linear phase lters have been widely used in DACS for over 20 years because they introduce no
group-delay distortion, minimize post ringing and have a phase response that is the same for all
frequencies but at the cost of pre-ringing. Conversely minimum phase lters have some group-
delay distortion, some minimal phase shift with frequency but little pre-ringing.
Most DAC digital lter designs tend to focus on the frequency response and neglect the time
domain response. However there is now an increasing interest in the eect that time-domain
properties of these lters have on the perceived audio quality, thus the PWD oers a choice
between 5 dierent lter types described in this section.
Generally speaking, linear phase lters are focused on maximizing the frequency domain while
minimum phase lters are designed to maximize the time-domain performance.
Group delay is a time domain issue where dierent frequencies arrive slightly out of time with the
other frequencies. A lter with no group delay (such as a linear lter) means that all frequencies
Filter