Asus Xonar Essence STU User manual

First Edition
May 2013
Copyright © 2013 ASUSTeK Computer Inc.
All Rights Reserved
Xonar Essence STU
Hi-Fi USB DAC (Digital-to-Analog Converter)
E8333
Opamp Swap Guide

2ASUS Xonar Essence STU Opamp Swap Guide
English
An operational amplier (op-amp) plays an important role in audio performance
and tonal style by creating distinct listening experiences. Catering to the needs
of audiophiles, Essence series streamline Op-Amp modications with easily-
swappable op-amp sockets.
1. Swap guide
Change all the OP-amps of the same types in the same slot. For example, if you
need to change DAC I/V (slot 1), you would need to change all the OP-amps
of the same types in all slot 1. If you need to change LPF (slot 2), you need to
change the OP-amps of the same types in all slot 2.
1. Serves as I/V (current to voltage convertor) that turns current from DAC into
voltage for output purpose.
2. Serves as Low Pass Filter that lters background noises.
3. Serves as DC Servo for the headphone. Changing this will affect the
headphone output.
NO. Items
1I/V Slot (slot 1)
2LPF Slot (slot 2)
3 DC Servo

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ASUS Xonar Essence STU Opamp Swap Guide
English
2. Instructions on swapping op-amps
1. Use an IC clamp to clasp an op-amp and
remove it vertically upwards.
2. Replace it with a new op-amp from the op-amp
kit.
To avoid reversion, ensure that the half-
moon opening on the op-amp points the
same way as that on the socket.
3. Disassembly
1. Remove the six screws on the bottom of the base.
2. Place your thumbs on top of the front panel and your other ngers on the
sides.
front panel

4ASUS Xonar Essence STU Opamp Swap Guide
English
4. After swapping, insert the front side rst then snap in the backend to replace
the top cover.
3. Push the front panel with your thumbs and use your four ngers to carefully lift
the top cover upward.

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ASUS Xonar Essence STU Opamp Swap Guide
English
Recommended OPamp pairing combinations
Brand Model name
NS LME49860
NS LME49720NA
NS LM4562NA
TI OPA2111
TI OPA2132
TI OPA2107
ADI OP275
ADI AD823
NJRC MUSE01
NJRC MUSE02
Sound Impression
DAC I/V Slot 1 DAC LPF Slot 2 Sound Impression
TI – OPA2107 TI – OPA2132 Brighter vocal, slightly less bottom sound
TI – OPA2107 NS – LME49860 Even brighter than the above combination, and more
detailed with less but tighter bottom sound
NS – LME49720 NS – LM4562NA Less warm than stock OP-amps, more extensive
detailed and dampened mid-range, Essence ST/STX
style
NS – LM4562NA NS – LM4562NA Wider sound stage but less detailed than the above
combination
NS – LM4562NA NJRC – MUSE02 Powerful, punchy sound with good sound stage; less
detailed present.
NS – LME49720NA NJRC – MUSE02 Brighter, thinner sound and more detailed than the
above combination
The following table lists the sound impression brought by different combinations of
op-amp pairing.
4. Op-amp pairing impression

6ASUS Xonar Essence STU Opamp Swap Guide
English
Exclusions from this limited Warranty
Service
ASUS does not warrant uninterrupted or error-free operation of this Product. The
warranty only covers technical hardware issues during the warranty period and
under normal use conditions. It does not apply to software issues or customer
induced damages or circumstances such as but not limited to:
(a) the Product has been tampered with, repaired and/or modied by non-
authorized personnel;
(b) the serial number of the Product, components or accessories has been altered,
cancelled or removed;
(c) the warranty seals have been broken or altered;
(d) obsolescence;
(e) damage (accidental or other) to the Product that is cosmetic, meaning damage
that does not impact the operation and functioning of the Product, such as
without limitation to rust, change in color, texture or nish, wear and tear,
gradual deterioration;
(f) damage to the Product caused by war, terrorism, re, accident, natural
disaster, intentional or accidental misuse, abuse, neglect or improper
maintenance, use under abnormal conditions;
(g) damage to the Product cause by improper installation, connection or
malfunction of a peripheral device such as printer, optical drive, network card,
or USB device, etc.;
(h) damage to the Product cause by improper installation, modication and/or
repairing of components
(i) damage to the Product caused by an external electrical fault or any accident;
(j) damage to the Product resulting from use outside of the operation or storage
parameters or environment detailed in the User’s Manual;
(k) damage to the Product caused by third party software or virus(es); or there is
software loss or data loss that may occur during repair or replacement;
(l) Un-usability due to forgotten or lost security passwords.
(m) Un-usability of or damage to the Product caused by contamination with
hazardous substances, diseases, vermin or radiation.
(n) fraud, theft, unexplained disappearance or willful act;

7
ASUS Xonar Essence STU Opamp Swap Guide
English
Except as provided in this Warranty and to the maximum extent permitted by law,
ASUS is not responsible for direct, special, incidental or consequential damages
resulting from any breach of warranty or condition, or under any other legal
theory, including but not limited to loss of use; loss of revenue; loss of actual or
anticipated prots (including loss of prots on contracts); loss of the use of money;
loss of anticipated savings; loss of business; loss of opportunity; loss of goodwill;
loss of reputation; loss of, damage to or corruption of data; or any indirect or
consequential loss or damage whatsoever caused including the replacement of
equipment and property, any costs of recovering or reproducing any data stored
on or used with the Product. The foregoing limitation shall not apply to death or
personal injury claims, or any statutory liability for intentional and gross negligent
acts and/or omissions by ASUS. Some jurisdictions do not allow the exclusion or
limitation of incidental or consequential damages; to the extent such jurisdiction is
governing this Warranty the above limitations do not apply to You.
The standard warrantee policy applies to all Xonar-related products.