Cayin HA-300 MK2 User manual

REV：1.0
User's Manual
HA-300 MK2HEADPHONE AMPLIFIER
POWER
ON OFF
VOLU M E
SOUR C ES
XLR RCA
OUTPUT
HEADPHONE AMPLIFIER HA-300MK2
STAND A R D
PHON E S
4PIN BAL.
STD
4PIN BALANCE
L
M
H
IMPE D ANCE
4.4 B A L .
4.4 BALANCE
MIN MAX

1
Table of Contents
Package Contents… … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … 2
Safety Precautions…………………………………………………………………………………2
Product Features……………………………………………………………………………………3
Specifications…………………………………………………………………………………………4
………………………………………………………………………………………5
… … … … … … … … … … … … … … … … … … … … … 6
System connection… … … … … … … … … … … … … … … … … … … … … … … … … … … … … … 9
Turning on…………………………………………………………………………………………11
Small Tips… … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … 11
Warranty Service… … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … 11
Troubleshooting
How to Install Vacuum Tubes… … … … … … … … … … … … … … … … … … … … … … … … … … 14
… … … … … … … … … … … … … … … … … … … … … … … … … … … … … … … 1…
Precautions
Front Panel Functional Description … … … … … …
Rear Panel Functional Description……………………………………………………………………………7
Top Panel Functional Description… … … … … … … … … … … … … … … … … … … … … … … … … … … … 8
Vacuum Tube Substitution…………………………………………………………………………8
… … … … … …
Connect to Headphones…………………………………………………………………………………10
Basic Operation……………………………………………………………………………12
………………………………………………………………………………………13
Table of Contents
Thank you for choosing Cayin HA-300 MK2 Direct Heated Triode Tube Headphone Amplifier
We have inserted protective foam inside the Vacuum Tube Cage in order to protect the vacuum tubes during
transportation. Please remove these foams before you connect the amplifier into your sound system. Fail to do
so might cause serious damage to the amplifier or disaster such as fire accident.
the amplifier. We suggest all customers read through this manual before they start to use the device.
We have prepared this user manual to help you understand the features and get familiar with the operation of

2
1. Unplug the power cord if you are not going to use the product for an extended period of time.
2. The machine will become hot after working for a long time. Please keep the unit's ventilation open and
install the amplifier at a well-ventilated place to avoid troubles and fire hazard.
3. Forbidden to operate when the output is open or shorted.
4. Do not attempt to service this product yourself. Opening the cover may expose you to dangerous voltage
or other hazards.
5. We are not responsible for any problems caused by checking and opening without permission of our
company. For service, Please contact a qualified service technician.
6.Do not place any objects filled with liquids such as vases or some others on the top or around.
7.Clean only with dry cloth.
8.Please move the amplifier carefully not to drop the unit or be subject to other strong shocks.
Package Contents
Safety Precautions
Please place the box in upright position according to the marking of the package. Please examine the product
package before you open it, the package should be free from any physical damage or water stain. You should
find the following items when you open the package:
1.Cayin HA-300 MK2 x1
2.Product User Manual x1
3.Warranty Card x1
4.AC Power Cord x1
5.Umbilical Power cable x1
6.Spare Fuses:
①.External Main Fuse x2（～220V-240V：T1.6AL250V； ～100V-120V：T3.15AL250V）
②.External Fuse for 300B Tube x4（T100mAE250V ）

3
Product Features
◆ TUNG-SOL 6SN7GTB x 2 for voltage amplification (driver tube).
◆ Gold Lion Genalex PX300B x 2 for single-ended class A power amplification (output tube).
◆ RCA 22DE4 x 4 vacuum tubes for high voltage rectification.
◆ Balanced (XLR) and single-ended (RCA) input.
◆ High-quality Neutrik 6.35mm single-ended, Nippon Dics 4.4mm balanced, Neutrik 4-pin
balanced headphone socket.
◆ High, Medium and Low, three levels of impedance options, perfectly match the impedance
of various headphones to ensure optimal performance.
◆ Powerful headphone output, handle demanding headphones with ample headroom.
◆ Upgraded version of toroidal power transformer in-house designed and manufactured for
HA-300MK2.
◆ Upgraded version of the high-quality frequency response EI output transformer in-house
designed and manufactured for HA-300MK2.
◆ Purist tube circuitry fully handmaded with point-to-point welding.
◆ Outboard power supply provides pure and steady power for the amplification circuit with
minimum interference.
◆ Independent graded power supply, voltage amplification circuit adopts independent
voltage regulated power supply, which effectively minimizes the interference to the
power supply, and ensures the optimal performance of the amplification circuit and best
acoustic fidelity.
◆ Improved circuit ensures the purity of the music and the distinctive charm of the single-
ended amplification circuit.
◆ Premium grade AUDIOCAPX (MultiCap) coupling capacitor improves resolving capability
and soundstage.
◆ High-Precision JRC MUSES72320V electronic volume controller with 41-steps ALPS
balanced potentiometer to provide low noise and accurate volume control.
◆ A set of speaker terminals as alternative output.
60sec startup delay circuit to enhance circuit protection and minimize pop noise when
startup.
◆ Lock on and quick-release aviation grade copper connectors with silver plated Teflon
umbilical cable provides low internal resistance, low dissipation, and more stable
transmission for outboard power supply connection.
◆ High-quality anti-shock buffer between critical tube components, chassis mainframe and
tube socket, remove microphonic of 300B direct-heated triode effectively and provide
quiet and realistic playback from sensitive headphones.
◆ Proper layout of the internal components and isolation shielding to ensure excellent
performance of the amplifier.
◆ Detachable vacuum tube shielding cage, easy to detach and install.

Specifications
Recommendation: is designed and
manufactured with our original parts and reaching the best results. We are not responsible for
problems and damages caused by non-original parts replacement in the amplifier. Please
keep all packaging materials for future use as you may need to repackage the amplifier in the
future.
Please fill in the product warranty card immediately and mail it to authorized dealer to
safeguard your after- sales service.
Note: Please make sure local voltage level is matched with the input level of the amplifier, which indicates on the
rear panel. Too low or too high voltage may cause problem. Please contact our company or our local agent
if you've found improper voltage.
Cayin HA-300 MK2 Direct Heated Triode Tube Headphone Amplifier
◆ To reduce the risk of electric shock, do not remove the cover.
◆ No user serviceable parts inside. Refer servicing to qualified service personnel.
◆ To reduce the risk of fire or electronic shock, do not expose the unit to rain or
moisture.
The lightning flash with arrowhead symbol is intended to alert user to the presence of uninsulated
“dangerous voltage” within the product's enclosure that may be of a risk shock to persons.
The exclamation point is intended to alert user to the presence of important operation and maintenance
(servicing) instructions accompanying the appliance.
4
TYPE
ITEM
SPECIFICATIONS
Headphone
Output
【Rated Output】
STD
1200mW+1200mW（L）；2200mW+2200mW（M）；5000mW+5000mW（H）
4.4 BAL.
800mW+800mW（L）； 2000mW+2000mW（M）；4500mW+4500mW（H）
4PIN BAL.
2000mW+2000mW（L）；2400mW+2400mW（M）；6000mW+6000mW（H）
【Frequency Range】
10Hz～45kHz ±3dB
【TH+D】
1%(1kHz)
【Sensitivity】
200mV～650mV
【S/N Ratio】
100dB （A-Weighted）
【Headphone
L：8~64Ω； M：65~250Ω； H：251~600Ω
【Headphone
6.35mm x1 ；4.4mm BALANCEx1； 4pin XLR x1,
Speaker
Output
【Rated Output 】
8W+8W
【Frequency Response】
10Hz~40kHz ±3dB
【TH+D】
1%(1KHz)
【S/N Ratio】
95dB（A-Weighted）
【Input Sensitivity】
400mV
【Output Impedance】
4~8Ω
【Input Impedance】
50kΩ
Others
【Input Connector】
XLR,RCA
【Tube used】
TUNG-SOL 6SN7GTB Genalex PX300B RCA ×2、×2、22DE4×4
【Dimension】
3 3
Power Supply：159×345×210mm AMPLIFIER：286×368×210mm
【Net Weight】
Power Supply：10KG AMPLIFIER：19KG
【Fuse】
～220V-240V ～100V-120V：T1.6AL250V； ：T2.5AL250V
【External Fuse for 300B】
T100mAE250V
【Power Consumption】
185W
【Working Condition】
Temp：0℃～40℃ Humidity： 20%～80%
【Storage Condition】
Temp：-20℃～70℃ Humidity： 20%～90%

Precautions
5
1. Connecting the power supply unit and AC socket.
After connected amplifier with the speakers and audio source, connect the quick-release
power supply cable between the main unit and the outboard power supply unit, then connect
with power supply unit to an AC power supply socket with the power cable.
2. Connecting and disconnecting of the quick-release power supply cable.
Connecting: Align the slots (marked with the red dot) of the connector with the slot (marked
with the red dot) of the socket of the power input/output on the machine (Figure 1), and plug
the power cable to connect.
Disconnecting: Firmly hold the lock ring of the connector and pull it out (Figure 2), the power
supply cable would be disconnected.
There should be sufficient space around the power outlet to facilitate plugging and
unplugging the power cord.
Power Supply Cable
COM COM
+ +
RCA
LEFT SPEAKER
XLR
SOURCES POWER INPUT
1:G 2:+ 3 :- 1:G 2: + 3:-
RIGHT SPEAKER
Align the slots
Figure 1Figure 2
Lock Ring
Aviation Grade
Connector
Aviation Grade
Socket
Connect to AC
Power Supply
T1AL250V.6
POWER OUTPUT 185
230 50
ZHUHAI S PARK ELE CT RO NIC EQUIPMENT C O., LTD.
RISK OF ELECTRIC SHOCK
CAUTION
DO NOT OPEN
HEADPHONE AMPLIFIER
-HA 300 MK2
SER.NO

Front Panel Functional Description
Diagram 1：HA-300 MK2 Front Panel
Attention:
“down” the button to turn on the amplifier, Press
again the button will resume to original position and
the amplifier will power off.
②. : Indicate the working status: The
indicator will remain always on when the amplifier is
in regular operation
③.Headphone Output Selector:
can select the suitable type of headphone output.
HA-300 MK2 offers three types output.
④.STANDARD: Output for headphones terminated in
6.35mm TRS connector
⑤.4.4 Balance Output：4.4 balance output for
headphone terminated in 4.4mm connector.
⑥.4PIN BALANCE: Output for headphones
terminated in 4pins XLR connector
①.
Power Indicator
With the switch you
Power On/Off: Turn on and off the amplifier. Press
matched output from the amplifier, three options were
offered: (L:8~64Ω; M:65~250Ω; H: 251~600Ω)
⑧.VU meter: monitor output level of the amplifier
⑨.
⑩.SOURCES: select balanced or single-ended input
.
.
⑦.IMPEDANCE: Select the most desirable: impedance-
Triode/ Ultralinear Indicator
When the TR Indicator is on: Triode working state
When the UL Indicator is on: Ultralinear working state
⑪Working State Indicator/Mute Indicator
Used to indicate the working state. The indicator will
be on when it is working normally. The indicator will
flicker for 30 seconds when it delays to work. The
indicator will keep flickering when it is at mute state.
⑫Volume Knob
Used to control volume
◆
adapter (not included in the package).
◆Listening through headphones at a high volume for extended periods of time can result in hearing
impairments.
◆Please do not use mono (TS) phone plug with this amplifier as this might cause serious damage
such as short circuit in the amplifier.
◆Please unplug the power plug from AC power circuit if the amplifier is not used for a long time
If your want to connect a 3.5mm terminated headphone to the amplifier, you need a 3.5mm to 6.3mm
1 2
POWER
ON OFF
46
37910
VOLUME
SOURCES
XLR RCA
OUTPUT
HEADPHONE AMPLIFIER HA-300 MK2
STANDARD
PHONES
4PIN BAL.
STD
4PIN B A L A NCE
L
M
H
IMPEDANCE
4.4 BAL.
4. 4 BA LANCE
MIN M A X
581211
Polarity Diagram for 4 PIN XLR
Balanced Headphone Jack
Polarity Diagram for 6.35mm
Headphone Jack.
L-
R-
L+
R+
Polarity Diagram for 4.4mm
Balanced Headphone Jack
6

COM COM
+ +
RCA
LEFT SPEAKER
XLR
SOURCES POWER INPUT
1:G 2:+ 3:- 1:G 2:+ 3:-
RIGHT SPEAKER
Rear Panel Functional Description
Please make sure the AC voltage of your local power supply match the voltage of the amplifier. Cayin
will not be responsible for the damage or accidents such as fire caused by incorrect input voltage
①.
Connect a balanced audio input to the
amplifier. Please make sure the left and
right channel is connected correctly
②.Single-ended input (RCA)
Connect a single-ended audio input to the
amplifier. Please make sure the left and
right channel is connected correctly
Balanced input (XLR)
Diagram 2: HA-300 MK2 Rear Panel
134 5 6 7 2
③.Right Channel Speaker Terminal connect to
the right channel speaker
④.Left Channel Speaker Terminal connect to
the left channel speaker
⑤.Power Input for Amplifier chassis
⑥.Power Output from power supply unit
⑦.AC Power Input with Fuse Holder: please
replace fuse with the same specification
Attention:
T1AL250V.6
POWER OUTPUT 185
230 50
ZHUHAI SPARK ELECTRONIC EQUIPMENT CO., LTD.
RISK OF ELECTRIC SHOCK
CAUTION
DO NOT OPEN
HEADPHONE AMPLIFIER
-HA 300 MK2
SER.NO
7

Diagram 3: HA-300 MK2 Top Panel
Top Panel Functional Description
◆
◆
◆
◆
The vacuum tube will become very hot during operation, please be careful and don’t get burned.
Please turn off the amplifier for 20 minutes before replacing the vacuum tube. Hold the base of vacuum tube
firmly and to avoid damaging the fragile part of the vacuum tube.
When install vacuum tube to the amplifier, position the vacuum tube correctly according to the alignment pin
before push the vacuum tube base into the socket.
Only used matched pair 300B and 6SN7 in the HA-300 MK2 amplifier.
Attention:
①. V5、V6、V7、V8: RCA 22DE4 Vacuum Tube
②. V1、V2: TUNG-SOL 6SN7GTB Vacuum Tube
③. V3、V4: Genalex PX300B Vacuum Tube
④. V3、V4 Vacuum Tube fuse300B
21 3
V8 22DE4
/
V6 22DE4
/
V7 22DE4
/
V5 22DE4
/V1 6SN7
/V2 6SN7 /
V4 300B
/
V3 300B
/
V3
FUSE V4 FUSE
44
8
Vacuum Tube Substitution
Vacuum Tube
Acceptable Substitution
22DE4
TUNG-SOL 6SN7GTB
Genalex PX300B
RCA 22DE4
6SN7GT、6H8C、ECC32、6N8P、CV181
300B

System connection
BALANCE Socket：USA System
1.
functions are following:
Music signal is transferred as balance signal European System
without the outside disturbance.
Professional XLR connectors are used to
raise reliability of connection.
This amplifier uses the USA System.
In the following two systems, professional XLR
If the XLR balance connector is used by European system, the
connectors are used for inside connection.
restored signal of pre-amplifier or main amplifier will be inverse.
Therefore, please setup the correct phase in advance.
The BALANCE socket is with XLR input. The
a. ：①PIN1：GND;
②PIN2：HOT;
③PIN3：COLD
◆ b. ：①PIN1：GND;
②PIN2：COLD;
◆
③PIN3：HOT
3. a
2.
Banana plug Normal plug
Connection method of CAYIN HA-300 MK2 with speaker cables or it will cause short circuit.
other audio equipments Take pictures below for your
reference.
Connect the speaker cables with the amplifier after
it is well connected with the speakers.
Connect both of the speakers to make sure of the Connection of speaker cables:
acoustic fidelity. 1. Unscrew the terminal knob
Please notice the signal direction indication of the 2. Insert the speaker cable
cables. 3. Screw the terminal knob
Do not mix up the positive and negative ends of
Ⅱ. :
1. Please refer to the manuals of other connected
Ⅰ. Speaker Connection equipments during the installation.
1. Check the impedance of your speakers. When 2. R refers to right channel while L represents left
using a pair of speakers, you can use speakers channel.
with an impedance of between 4 and 8 ohms. BE 3. Do not fasten signal cable together with power
SURE TO USE THE MATCHING TERMINALS. cable and speaker cables. It will worsen the
2. Please notice the polarity of the cable and do not acoustic fidelity.
mix up the positive and the negative ends. Ⅲ. Connection of power cord:
NOTE：Connect the speaker cables and signal cables first
◆and then insert the power cord into the power
socket.
◆Ⅳ.
◆
◆
:
Audio Connection
①
②③
GND
HOT
COLD
①
②③
GNDCOLD
HOT
9
到音频输出端
HA-300 MK2
CS-100CD
L
R
L
R
L
R
L
R
CS-100CD
ANALOG OUTPUT DIGITAL OUTPUT
USBCOAXIALOPTICAL
OPTICALCOAXIAL
BALANCEUNBALANCE
RIGHT LEFT RIGHT LEFT
AES/EBU
COM COM
+ +
RCA
LEFT SPEAKER
XLR
SOURCES POWER INPUT
1:G 2:+ 3 :- 1:G 2: + 3:-
RIGHT SPEAKER
T1AL250V.6
POWER OUTPUT 185
230 50
ZHU HAI SPA RK EL ECTRO NIC EQU IPMEN T CO., LTD.
RISK OF ELECTRIC SHOCK
CAUTION
DO NOT OPEN
HEADPHONE AMPLIFIER
-HA 300 MK 2
SER. NO
RED
BLACK
TO SPEAKER（L）
SPEAKER（L）SPEAKER（R）
RED
BLACK
TO SPEAKER（R）
Connected to power socket
Connect to Audio
Output of CD Player.
Connect to Audio
input of HA-300 MK2

扬声器连接
Selecting Headphone Connection provided three types of headphone output: 4-pins XLR for balanced,
4.4mm Balanced ,6.35mm for singled-end, we have optimized the headphone amplifier to perform
satisfactory for all outputs, user are free to use any headphone output according to their need without
worrying one is better than the other.
Single-ended Headphone Connection
HA-300 MK2 provides one set of 6.35mm headphone input,
the pin definition of the headphone connector is as illustrated.
Headphones terminated with 3.5mm connector will require a 3.5mm
to 6.35mm adapter in order to use it with this headphone amplifier.
4.4mm Balanced Headphone Connection
 HA-300 MK2 provides one set of 4.4mm headphone input, the pin
definition of the headphone connector is as illustrated.
 Headphones terminated with 2.5mm connector will require a 2.5mm
to 4.4mm adapter in order to use it with this headphone amplifier.
XLR Balance Headphone Connections
 HA-300 MK2 provide one set of 4-pin XLR headphone input, the pin
definition of the XLR connector is as illustrated.
 Headphones terminated with dual XLR (3-pins), 4.4mm or 2.5mm
balanced headphone connectors will require corresponding XLR4
adapter in order to use it with this headphone amplifier.
IMPEDANCE matched output
 Headphones are currently available from 8Ω to 600Ω, in view of this wide range of impedance rating,
HA-300 MK2 provides three sets of impedance matched outputs (L:8~64Ω; M:65~250Ω; H: 251~600Ω) to
ensure the headphone amplifier can handle vast variety of headphones satisfactory.
 We recommend users to start with the output setting that match the impedance rating of your
headphone.
 It is technically safe to select any impedance setting for your headphone. You can try other impedance
setting without worrying causing any damage to your headphone.


Connect to Headphones
Attention:
◆
use the 6.35mm headphone output.
◆Single-ended headphone cannot use an adapter to plug into the XLR4 balanced headphone output
of the HA-300 MK2, it can cause damage to your headphone and/or headphone amplifier.
◆Turning the volume to the minimum when you exchange the Headphone.
Balanced headphones can convert into single-ended headphone with appropriate converter and
Polarity Diagram for 4 PIN XLR
Balanced Headphone Jack
Polarity Diagram for 6.35mm
Headphone Jack.
L-
R-
L+
R+
Polarity Diagram for 4.4mm
Balanced Headphone Jack
10

Read the Manual —— Please read the user's manual carefully before installation and operation.
Keep the Manual —— Please keep the manual for future reference.
Warning Signs —— Don't tear off or rub off the serial number.
Operation —— Do the operations as you are instructed in the Manual.
Parts —— If you are going to use parts not supplied by our company like power cord, fuses etc please make sure that parts
you used are compatible with the safety requirements. Or it will cause fire or electric shock.
Placement —— Put the amplifier on a level place. Make sure that it doesn't bring damage to the children, adults and the
amplifier itself.
Power —— Please make sure the local voltage is the same level as indicated on the rear panel.
Overload —— If the power socket is overloaded with other equipment, it will cause fire or electric shock.
Warranty Service —— Do not open the product and change the components inside yourself. Opening the cover may expose
you to dangerous voltage or other hazards. The warranty doesn't extend to any product that has been
opened by you without permission of our company.
Troubleshooting ——If you encounter any abnormal behavior during setup or playback, please refer to the advice in next
pages of this manual to recover your amplifier back to normal operation. If you fail to rectify the
problems after that, please contact your authorized dealer for technical support.
Small Tips
Turning On
Before turning on the amplifier please make sure all connections are right and power supply is stable.
Turn on the amplifier, the power indicator will be on and the working indicator will keep flickering.
The working indicator will be on after 60 seconds. It means that the amplifier is working normally. If the working
indicator is off, please turn off the power and contact with our local agent or our company.
Select the right audio source channel, adjust the volume to a certain position and then you can enjoy the music you
prefer.
NOTE：1. When the audio system is under working state, don't unplug the signal cable or speaker cables, or it will cause
damage to the amplifier and other equipments.
2. It should at least takes 2 minutes before you turn on the power again, or it will cause damage to the vacuum tubes.
◆
◆
◆
1. The Product is warranted for a period of twelve (12) months from the date of original purchase (the “Warranty Period”).
Replacement Products are warranted for the remainder of the original twelve (12) month warranty period. Six-month
warranty on stock vacuum tubes.
2. The defective product must be returned to your dealer or our company for repairing when your dealer or our company
accepts your requirement.
3. The warranty doesn't extend to any product that has been opened by you without permission of our company.
The information in this manual is subject to change without further notice.NOTE：
Warranty Service
11

12
Basic Operation
Please make sure all connections are correct and power supply voltage is stable before turn on the amplifier.
1. Turn on the amplifier, the power indicator will light up.
2. When the power indicator remains lighted up steadily, the amplifier is ready for operation. If the power
indicator will become steady (always ON). It means that the amplifier is ready for operation. If the power
indicator did not light up, the amplifier is malfunction, please turn off the power and contact your local dealer
for service support.
3. The tubes regulated power supply might require around 30-60 seconds to ramp up the voltage gradually, it is
normal if you heard ting-ting noise from your headphone or speaker during this time.
4. The vacuum tube might require 10 minutes of warm up before they reach optimum performance.
5. Select your input source: XLR for balanced input, RCA for single-ended input.
6. If you are using single-ended headphone, insert the 6.35mm connector of your headphone into the
STANDARD headphone output on the front panel. Switch the headphone output selector (PHONES) to STA.
7. If you are using a 4.4mm balanced headphone, insert the 4.4 connector of your headphone into the 4.4
BALANCE headphone output on the front panel. Switch the headphone output selector (PHONES) to 4.4 BAL.
8. If you are using a 4pin XLR balanced headphone, insert the XLR4 connector of your headphone into the 4 PIN
BALANCE headphone output on the front panel. Switch the headphone output selector (PHONES) to 4 PIN BAL.
9. Select the appropriate output (L, M, or H) on the IMPEDANCE switch according to the specification of your
headphone for optimized performance.
10. Adjust Volume to appropriate level and enjoy your music.
Attention:
◆
might cause damage to the amplifier or associated equipment
◆You can swap headphones during playback, but to avoid damaging your sensitive headphone and
protect your hearing, please turn the volume down to 0 when you unplug or plug in another pair of
headphone.
◆If you have turn off the amplifier, please wait 2 minutes before you turn in on again, ot it might cause
damage to the vacuum tubes.
Please do not disconnect your interconnect when the amplifier is operating, this

Please follow the instruction in the manual in order to keep the amplifier work in its best state. If wrongly
operated and you thought that would be troubles please check according to following tips to look for the exact
reasons.
Troubleshooting
NOTE: is the registered trademark of Zhuhai Spark Electronic Equipment Co., Ltd.
13
Problem
Cause
Solution
No Sound
after power
on
Power
Indicator is
OFF.
Power is not connected
Connect power cord securely
Check main power supply
Main fuse is out.
Replace fuse with same
specification
Power
Indicator is
ON.
NO input signal .
Check source equipment is working
Select input source correctly
Volume at minimum position
Turn up volume
Interconnect not properly connected
Connect all cables securely
Headphone cable not properly
connected
Connect headphone cable properly
Headphone output not specified
correctly
Select headphone output correctly
Selected the wrong output
Select headphone or speaker output
correctly
Umbilical Power cable not properly
connected
Reconnect the umbilical power
cable, position the alignment groove
correctly before tighten up the
screw-threaded connector
No sound from
left or right
channel
V3 or V4 300B vacuum tube fuse is
broken
Replace the fuse with the same
specification
300B vacuum tube is damaged
Replace the 300B Vacuum Tube
Excessive noise
Input source badly connected
Install interconnect properly
Interconnect grounding
disconnected
Replace interconnect
Equipment malfunction
Contact authorized dealer for
technical support
Soundstage and imaging
not focused
Left and right channel of source
equipment reversed
Reinstall related cabled correctly
Headphone cable polarity reversed
Speaker cable polarity reserved

How to Install Vacuum Tubes
Pin No. 9 Pin No.1
How to Install 9-Pin Vacuum Tubes
12AU7(ECC82)、12AX7(ECC83)
Applicable vacuum tube:
、5BK7、12BH7、
12AT7(ECC81)、6922（ECC88), etc. 9-Pin vacuum tubes.
Instructions to Change and Install the vacuum tubes:
To install a nine-pin vacuum tube, align the pins of the vacuum
tube with the holes of the tube socket and insert the tube
vertically up and down (as shown in the figure above).
Please note that when installing the nine-pin vacuum
tube, pay attention to the alignment of the vacuum tube
pins with the holes of the tube socket. Otherwise wrong
insertion will cause damage to the vacuum tube and
prevent the amplifier from working properly, which may
lead to failure of the amplifier.
Positioning Pin
How to Install 8-Pin Vacuum Tubes
Applicable vacuum tube:
KT150、KT170、KT88、6550、EL34、6V6、6SN7、6SL7、5AR4,
etc. 8-pin vacuum tubes.
Instructions to Change and Install the vacuum tubes:
To install an eight-pin vacuum tube, align the positioning pin of
the tube with the grooves in the positioning holes of the tube
socket, and install the tube by pulling up and down vertically
(as shown in the figure above).
Please note that when installing the eight-pin vacuum tube,
pay attention to the alignment of the vacuum tube positioning
pin with the positioning hole of the tube socket. Otherwise
wrong insertion will cause damage to the vacuum tube and
prevent the amplifier from working properly, which may lead to
failure of the amplifier.
How to Install 4-Pin Vacuum Tubes
Applicable vacuum tube:
300B、2A3 etc. 4-pin vacuum tubes .
Instructions to Change and Install the vacuum tubes:
To install a four-pin vacuum tube, please pay attention to the
thickness of differnet pins of the vacuum tube and the size of
the tube socket hole. Thick pin should be aligned with the big
hole, and the thin pin should be aligned with the small hole.
Install the tube vertically up and down (as shown in the figure
above).
Please note that when installing the four-pin vacuum tube,
pay attention to the thickness of differnet pins of the vacuum
tube and the size of the tube socket holes. Otherwise wrong
insertion will cause damage to the vacuum tube and prevent
the amplifier from working properly, which may lead to failure
of the amplifier.
Thin Pin Thick Pin
Big Hole
Small Hole
How to Install Big 4-Pin Vacuum Tubes
Applicable vacuum tube:
845、805、211 etc. 4-pin vacuum tubes.
Instructions to Change and Install the vacuum tubes:
To install the big four-pin vacuum tube, align the vacuum tube
positioning pin with positioning pin slot of the tube socket and
then rotate 45° clockwise to tighten. (As shown in the picture
above). To take out the big four-pin vacuum tube, turn the tube
45° counterclockwise and take it out upward after loosening.
Please note that when installing the big four-pin vacuum
tube, pay attention to the alignment of the vacuum tube
positioning pin with positioning pin slot of the tube socket and
then rotate 45° clockwise to tighten. It is strictly forbidden to
install the vacuum tube when the positioning pin is off or
missing. Otherwise wrong insertion will cause damage to the
vacuum tube and prevent the amplifier from working properly,
which may lead to failure of the amplifier.
Positioning Pin
Positioning Pin Slot
14