Woo Audio WA7 Fireflies User manual

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 1
WOO AUDIO WA7 Fireflies
2nd Generation Since March 15, 2016
Pure Class-A Single-ended Vacuum Tu e Headphone Amplifier
&
24-Bit/384kHz Digital to Analog Convertor
Owner’s Manual
Please review this manual before operating your WOO AUDIO™ product.

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 2
Important afety Information
CAUTION: Amplifiers are shipped without the vacuum tu es
installed. The end user must install the tu es, taking great care to
install them correctly in the appropriate sockets. Incorrect
installation will result in serious damage not covered by the
warranty.
Turn off immediately in the event of malfunction!
Should you notice smoke or an unusual smell coming from the
equipment, turn it off immediately. Continued operation could
result in injury.
Do not disassemble
The unit contains high voltage circuitry. Touching the amplifier’s
internal parts may result in injury. In the event of malfunction.
the product should e repaired only y a qualified technician.
Keep out of children
Failure to o serve this precaution could result in injury
WARNING: Failure to follow these instructions could result in
fire, electric shock, or other injury or damage.

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016
Table of Contents
IMPORTANT AFETY INFORMATION 2
TABLE OF CONTENT 3
OVERVIEW 4
GETTING TARTED 7
QUICK IN TALLATION 10
OPERATION 13
FAQ - FREQUENTLY A KED QUE TION 14
WARRANTY AND ERVICE 15
PRODUCT PECIFICATION 16
REVIEW 17

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 4
Overview
The multi award-winning WA7 Fireflies is improved and better than ever. Among
the numerous enhancements is a newly designed ESS SA RE Reference DAC that is
crucial to the WA7's sound quality. The new ESS DAC reveals the elusive – yet
desired – dynamics and details in your digital audio files. The new XMOS xCORE-
AUDIO asynchronous clocking US controller is compatible with PC, Mac, Android
and iOS devices. Other enhancements include improved analog circuitry, premium
Teflon tube sockets, and US connector.
The WOO Audio WA7 “Fireflies” Amp/DAC is a com ination of high performance
vacuum tu e headphone amplifier with a uilt-in USB Digital-to-Analog Converter. It
employs a pure tu e design, utilizing 6C45 tu es in a class-A, single-ended topology,
with transformer coupled outputs. No semi-conductors used in the entire signal path.
The D-A converter is designed to e capa le of up to 24- it/384k sampling rates. Pure
data integrity is maintained while it is transmitted via standard high speed USB 2.0
interface operating in asynchronous mode.
The high quality construction features include a pair of Nickel Alloy core output
transformers, all-aluminum chassis with no screws visi le from any viewing angles, a
linear external power supply for amplification circuitries, a custom uilt toroidal power
transformer, and multi-layer military grade PCBs.
The dedicated port for in-ear-monitors carries a full range of volume controls ensuring
minimal noise. Despite its incredi ly compact size, “Fireflies” is a power-house with the
capacity to drive almost any demanding audiophile headphones. To accommodate
different system setup needs, “Fireflies” can also e used as a stand-alone D-A
Converter.

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 5
Identifying the 2nd Generation Fireflies:

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 6
Features:
oHandmade output transformer with Nickel Alloy core
o24-Bit, 384kHz high resolution play ack
oUltra-low jitter USB 2.0 runs on Asynchronous mode
oHigh and low impedance output facilitated via toggle switch on ack panel
oOpen load protection will automatically engage to prevent the amp from
damaging when no headphones are plugged in
oMulti-functional switch for USB input, RCA input, and RCA output via D/A.
oThe RCA connectors can e used either as RCA analog inputs or USB DAC
preamp outputs
oAll-aluminum chassis with no screws visi le from any viewing angles
oHigh clarity tu e protection glass
oMulti-layer military grade PCBs
oCustomized driver for Windows Vista/XP/7/8
oUSB Audio Class 2.0 is natively supported y Apple OS X version 10.6.4 and
a ove without installing driver

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 7
Getting tarted
What’s in the box?
① Um ilical DC Power Cord
② Micro-fi er Polishing Cloth for glass and metal cleaning
③ Anti-slip silicone ru er glass pads (4pcs)
④ External Power Supply
⑤ Tu e Protection Glass
⑥ WA7 Fireflies Amplifier
⑦ 6C45 Matched Pair Tu es
⑤
⑥
* U B, AC power cord,
and inter-connection
cables are not included.
①
②
④
③
⑦

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 8
Front Panel
Top Panel
Back Panel
7
8
9
⑦ Volume control for headphone outputs
⑧ 3.5mm or 1/8” mini In-Ear-Monitors
headphone jack
⑨ 6.35mm or 1/4"headphone jack
⑩
Tu e sockets for 6C45 vacuum tu es
Please pay close attention to vacuum
tu e installation alignment marks!
⑪ USB 2.0 digital input
⑫ RCA analog input
⑬ Input-output switch
RCA –RCA analog input
USB – USB 2.0 digital input
D/A – Digital to Analog output via RCA
⑭ High and low headphone impedance
switch
HI-Z – High impedance
LO-Z – Low impedance
⑮ Um ilical power cord socket (male)
⑯ Power switch
I – ON
O - OFF
The RCA connectors can e used
either as RCA analog inputs or USB
DAC RCA line-out outputs.
11
10
12
16
15
14
13

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 9
External Power upply
DC power connection
Connections
The WA7 Firflies can e connected in one of the following ways.
Computer
RCA
⑪
Um ilical cord socket (female)
⑫
Power LED light
11
12
13
14
⑪
AC power inlet
⑫
Fuse ox
slow low fuse, 400mA@115V or
200mA@230V
RCA line-out to
active monitors
External
Power upply
AC power connection
A
B
C
USB 2.0
CD player or analog source
RCA
USB 2.0
Digital-to-Analog Convertor
Computer
RCA
line-out to
power amp
IEMs Full-sized
headphones

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 10
Quick Installation
Installing tubes
Umbilical Power Cord Installation
20
Align the tu e in
the tu e socket
according to the
RED arrows
Hold
the tu e
firmly, slowly
inserting it down
into the socket.
Care must e
taken to only
apply force
perpendicular to
the tu e socket;
never insert it at
an angle. Apply a
slight rocking
motion for the
tu e which is
harder to insert;
ut, never apply
circular motion.
Connecting the Amplifier unit
Align the female plug to the DC input
connector. The “arrow” marking on the plug
should face up when it is properly oriented.
Insert the plug into the socket and turn the
locking ring on the plug until fully tightened.
Connecting the Power upply unit
Align the male plug to the DC input
connector. The arrow marking on the plug
should face up when it is properly oriented.
Insert the plug into the socket and turn the
locking ring on the plug until fully tightened.

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 11
Installing the AC power cord (customer supplied) :
Plug the power cord into the AC inlet; see ⑬ in the a ove diagram. The AC inlet socket is a standard IEC
type. You will need to o tain the correct type for your region if it not supplied with your order.
Installing Tube Protection Glass:
Do not hit the tubes by the glass. The glass is heavy. Handle with both hands.
Powering Up
To power up on the WA7 Fireflies, flip the power switch ⑯ to the “I” position. The LED on the
power supply will lit. Vacuum tu es should lit at the same time.
U.S. European
U.K.




©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 12
U
sing the Asynchronous U B 2.0 port:
The WA7 Fireflies offers a USB 2.0 port ⑪, refer to the a ove diagram, which is compati le with
Windows or Mac OS computer.
Installing the U B driver
*These steps only apply for Windows 7/8/10.
1. Plug in the USB 2.0 ca le to the WA7 Fireflies and your computer.
2. Install the WA7 Fireflies Driver from the downloaded file from
http://www.wooaudio.com/drivers/WA7.1-driver-for-Windows.exe
3. Unzip the downloaded file. Locate setup.exe file and run it.
4. Follow on-screen instruction to complete the installation. Windows restart may e
required.
5. Set USB Speakers as your default audio output.
Go to My Computer -> Control Panel -> Hardware and Sounds -> Sounds
-> Click XMOS USB Speakers -> Click Set Default
6. Now you're ready to enjoy music from your computer.
Configuring media player
TIPS: It is strongly recommended to use a media player that supports ASIO output
mode for the highest play ack quality.
Changing Output mode
Example is given for JRiver Media Center.
Tools -> Options -> Audio Output -> Output mode -> select
XMOS USB Audio 2.0 ST 3066 [ASIO]

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 1
Operations
NOTE: Only one headphone output is operational at a time. When oth headphone
jacks are plugged in, only the ¼” output is operational.
DO NOT
oTurn on the amp efore properly installing ALL tu es and power supply.
oBlock vent holes of the power supply.
oUse tu es that are not approved y Woo Audio.
oAlign the male plug to the DC input connector. The arrow marking on the plug
should face up when it is properly oriented. Insert the plug into the socket and
turn the locking ring on the plug until fully tightened.
oRemove any tu es or the um ilical power cord while the amp is operating.
oTouch tu es (they are extremely hot) after warm-up.
oLeave the amp running unattended. (We suggest a maximum of 8 hours of
continuous use, allowing the tu es time to cool efore using again)
oPlace amplifier in direct sunlight. Extended exposure may cause discoloration to
the anodize aluminum.
DO
oPlace the amp away from any wireless or frequency-emitting devices such as
mo ile phones, PDAs and radios, to avoid noise interference.
oKeep away from water or excessive moisture.
oTurn off the amp if its sound is a normal.
oAllow a minimum of 2 inches of air clearance for heat dissipation.
oAllow approximately 3 minutes of warm-up.
oAllow the tu es to cool down efore replacing them.

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 14
FAQ - Frequently Asked Questions
Computer cannot find the WA7 Fireflies U B DAC.
oCheck USB ca le connection and make sure the ca le is USB 2.0 compati le.
oSee “Installing USB driver” section for configuration.
No sound is coming out of the headphone jack.
oCheck you have selected the correct position of the Input-Output switch. Check input connection.
Check computer USB output setting if USB input is used.
No sound is coming out of the mini headphone jack.
oOnly one headphone is operational at a time. Disconnect headphones from the ¼” jack to ena le
output of the mini phone jack.
There is static noise, or one channel is dropping out.
oRe-seat all tu es. Make sure that all tu es are securely installed.
The LED does not light.
First check if the AC cord is installed. Next, check if the um ilical cord is securely attached etween the
amp and the power supply. If the fuse is urnt, see the following instruction on how to replace a fuse. The
fuse type is 400mA@115V or 200mA@230V, slow low type.


Insert a small flat
screwdriver into the
fuse door located on
the AC inlet.
Pull the fuse door
to open it.
The fuse holder
may e released
from the AC inlet.
Replace the urnt
fuse with a new one


©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 15
Warranty and ervice
Woo Audio warrants this product free from defects in materials and workmanship for
one (1) year from the original date of purchase. The tu es are warranted for 30 days
unless otherwise stated. In the event that your Woo Audio product requires servicing,
please contact us directly to receive return instructions. Please do not discard original
packing materials. If for any reason, the equipment is to e shipped ack to Woo Audio,
please use the original packaging, including a copy of sales purchase documents and a
detailed explanation of the pro lem(s).
Send service inquiry to [e-mail]
Any modification not authorized by WOO AUDIO will void this warranty.

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 16
Product pecification
Model: WA7 Fireflies
Headphone amp design Single-ended, class-A, transformers output
Power supply Linear external power supply. Tu e power supply optional
Tu es used One matched pair of 6C45, one tu e per channel
USB receiving chipset: XMOS xCORE-AUDIO
DAC chip ESS SABRE ES9018K2M Reference DAC
Sampling Rate: Up to 24-Bit, 384kHz
Inputs: 1 Asynchronous USB2.0, 1 RCA
Outputs: 1 1/4" and 1 1/8" headphone outputs, 1 RCA (same
connector as the input)
Headphones impedance 8-600 Ohms
RCA input impedance 100 Kilo-Ohms
Max Output: Approx. 1 watt @ 32 ohms
Frequency response: 11Hz to 27kHz, +/-0.5dB
Distortion: <0.03%
S/N: 95dB
Power consumption 25W max
Mains Supply: 100-120V, 220-240V, 50/60Hz, user selecta le
Fuse slow low fuse, 400mA@115V, or 200mA@230V
Amp ody and PSU finish Anodized Aluminum
Dimension: AMP: 4.8" L x 4.8" W x 5.1" H with glass
PSU: 7" L x 3.5" W x 2.2" H
Weight: AMP - 5.3 l s / 2.4kg, Glass - 3.3 l s / 1.5 kg
PSU - 2.8 l s / 1.4 kg

©2016 WOO AUDIO
tm
Inc. All rights reserved. www.wooaudio.com Rev 1. . March 15, 2016 17
Reviews
The WA7 is one of the few home headphone amps that sounds great with full-size and
in-ear headphones. - Audiophiliac
This is possibly the most linear DAC and headphone amp 've heard.
-Positive Feedback
The Woo reaches DEEP, and is POWERFUL. t’s everything you want it to be and just
a tad more … because it’s so damn sexy you feel like you stole it from the future
somehow. -Humanovation
Appreciable about the WA7 was that whatever headphones or EMs used with it, the
performance was consistent. -Currawong @ head-fi.org
the WA7 is practically a steal in terms of sound quality and physical presentation. - HP
Soundings
Woo Audio is committed to continuously improve its products.
We therefore reserve the right to improve on our design without notice.