Line Magnetic LM-502CA User manual

VACUUM TUBE AUDIO DAC UNIT
LM-502CA

Thanks for choosing our Line Magnetic LM-502CA Digital-to-Analog Convertor as an important part
of your music system and please read the manual carefully before installation and operation.
01
Table of Contents
Table of Contents ------------------------------------------------------
Package Contents ------------------------------------------------------
Product Features -------------------------------------------------------
Specification ------------------------------------------------------------
Safety Precautions -----------------------------------------------------
Functions Description ------------------------------------------------
Connection --------------------------------------------------------------
Turning on --------------------------------------------------------------
Maintenance ------------------------------------------------------------
Warranty Statement ---------------------------------------------------
Troubleshooting -------------------------------------------------------
Suggestions:
LM-502CA DAC 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
DAC.
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Please carefully check the package first and then open the package. Package contents include:
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Package Contents
1. Line Magnetic LM-502CA 1
2. Main Fuses 2
3. Power cord 1
4. 1.5V Batteries(AAA) 2
5. User’s Manual 1
6. Warranty Card 1
Note:All other parts except above are not included.
Recommendation:
Keep all packing materials for future use and please fill in the warranty card for registration of warranty.
Note:
Please make sure local voltage level is matched with the input level of the DAC which indicates on the
rear panel. Too low or too high voltage may cause problem and in case you've found improper voltage please
contact our company or our local agent.
Product features
. LM-502CA digital DAC takes Xmos USB audio technology which utilizes high speed USB 2.0 receiving
and decoding 32bit/192kHz high resolution digital signals.
. LM-502CA digital DAC is designed with top grade ESS 9016 DAC chips.
. LM-502CA digital DAC features five digital inputs: AES/EBU, BNC, USB, OPTICAL, and COXIAL.
It is an asynchronous design with awesome performance from its low distortion, Ultra-low-jitter Clock
Recovery technology to high quality separate power supply for Analogue and Digital part: Toroid power
transformer for Digital part while EI power transformer for Analogue part.
. LM-502CA digital DAC offers a choice of outputs: Tube output or Solid-state Output.
. Digital circuit has taken high speed rectification circuitry while Analogue parts has taken 6Z4 for tube
rectification.
. LM-502CA will lock onto any signal input at 44.1, 48, 88.2, 96, 176.4 and 192kHz with the front panel
LCD display showing the input frequency.
. LM-502CA incorporates LM Audio's world class leading Tube analogue output stage. Two pieces of
12AU7 are employed at Tube buffer to true tube output.

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Note : Line Magnetic Audio reserves the right to change specifications at any time
without further notice in advance if products are upgraded. Specifications on the manual
only show the specifications of the DAC you bought.
Frequency response：15Hz～50kHz（ 1dB）
Sampling Rate：32bit 44.1KHz 48KHz 88.2KHz 96KHz 176.4KHz 192KHz
Digital Input Impedance：75ΩOutput Impedance：2KΩ (Tube),600Ω(Solid State)
Output Level： 3V 0.5dB(Tube) 2.5V 0.5dB(Solid State)
Dimension（W×D×H）： 430mm x 325mm x 105mm
Net Weight：6.7kg
Power Consumption：24W
Working Condition： Temperature：0℃ ～40℃ Moisture：20%～80%
Storage Condition： Temperature：-20℃ ～70℃ Moisture：20%～90%
Dynamic Range：120dB（A Weighted）
S/N Ratio： 92dB(Tube) 98dB(Solid State)
THD： 0.5%(Tube) 0.02%(Solid State)
Power Requirements：230V
Specification
Safety precautions
1. Unplug the power cord if you are not going to use the product for an extended period of time.
2. Temperature will become higher after working in long period of time and please keep the unit's ventilation open
and install the DAC at a well-ventilated place to avoid troubles and fire hazard.
3. Forbidden to operate as unloaded.
4. Forbidden to operate when the output is open or shorted.
5. Do not attempt to service this product yourself. Opening the cover may expose you to dangerous voltage or other
hazards.
6. 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.
7. Do not place any objects filled with liquids such as vases or some others on the top or around.
8. Clean only with dry cloth.
9. Please move the DAC carefully not to drop the unit or be subject to other strong shocks.
10. Unplug the power cord if you are not going to use the product during thunderstorm.
Carefully read and follow the Manual for installation:
1. Do not place the product near heat sources such as radiators, heat registers or other products that produce heat.
2. In order to avoid being overheated please keep the unit’s ventilation open.
3. Do not expose this appliance to rain or moisture.
4. DAC should install steadily and make sure all four feet are on the same level.
5. Keep the DAC in a certain distance so that it can be easily connected.
6. Keep the DAC in 15CM’s distance to the surrounding walls.
*Note：If you need to use the USB function，Please login
“www.lm-audio.com”download USB driver for V1.61。

The lightning flash with arrowhead symbol, within an equilateral triangle, is intended to alert users
to the presence of uninsulated “dangerous voltage” within the product’s enclosure that may be of
sufficient magnitude a risk shock to persons.
The exclamation point within an equilateral triangle is intended to alert the user to the presence of
important operating and maintenance (servicing) instructions in the literature accompanying the
appliance.
RISK OF ELECTRONIC SHOCK
DO NOT OPEN
CAUTION
.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.
Note: Input voltage level of the amplifier is 230VAC～ 5% and please make sure that the supply
voltage is proper. Too low or too high voltage may cause problem or reduce its life.
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Safety precautions
Functions Description
Front Panel:
45
3
2
1 67
Power Switch
Signal Indicator
Tube Output Indicator
Transistor Output Indicator
1
2
3
4
Output Selector
Previous Input Selection
Next Input Selection
5
6
7

Suggestions:
Here is the standard way of connection for LM-502CA with other audio equipments.
Please take pictures below for your reference:
Audio Connection
1.During installation please always refer to other products’ operation manuals.
2.Please do not insert the power cord into the main socket only if all other instruments are well connected.
3.R refers to right channel while L represents left channel.
4.Please take the right guidance for connection as wrong connection may cause noise or low grade function.
5.Do not fasten signal cables together with other cables just like the power cables to avoid disturbance.
Connection
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Functions Description
Rear Panel:
1 2 3 4 5 6 7
4
5
3
2
1
6
7
Analog Outputs
PC-USB Input
Optical Input
Coaxial Input
BNC Input
AES/EBU Balance Input
Power Socket with Main Fuse.

Connect to AC 230V ~50HZ
Note:
1.It is normal that power transformer becomes hot for extended period of operation.
2.Please unplug the power cord if you’re not going to use the product for an extended period of time.
3.Please do not insert the power cord into the mains socket only if all other instruments are well connected
4.To prevent damage to the system never cut off the speaker cables while the unit is ON.
5.In order to protect the tubes please re-switch on the DAC after turned off in two minutes.
Warning:
Please make sure corresponding voltage is the same as required. We are not responsible for
damage caused by misuse of unsuitable voltage.
Precautions:
Connection of the power cord:Connect the speaker cables and signal cables first and then plug the
power cord into the power socket. Before turning on the amplifier please make sure all connections
are right and power supply is stable.
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Turning ON
Before turning on the DAC please make sure all connections are correct and the power
supply is stable.
1.If you are going to use PC-USB function please install the USB driver program first and the software
is in the Driver disk attached. Please kindly note iOS system does not need to install the driver software.
Method of installation of the driver program:
2.Please connect the computer and the DAC with USB cable and
then turn on the DAC. Find the driver software in the driver CD
and install according to the instruction step by step. If the
program is correctly installed you will find an icon of the driver
program at the lower right hand side of the computer.
3.Open Audio Setup of the computer and choose XMOS Audio 2.0
Output for the Audio output instrument.
4.Turn on the DAC and the power LED will be on. It shines
indicating that the amplifier is working.
5.In 30 seconds the display will show INPUT: USB SR:-----. It
means the DAC functions very well.
6.Or if the power LED is not on please contact with our local agent
or our company.Select the right sound source and you can enjoy
the music you prefer.
7.Open the media player and play music. Choose USB input and
the display will show the sampling rate of the music currently
played.Connect your sound source with digital output (Optical,
RCA Coaxial, BNC Coaxial, AES/EBU, USB) to the DAC and select the corresponding input by buttons on
the front. Then you can enjoy the music with the full system and the display can show the sampling rate of the
music played.

07
Clean the DAC hwith soft dry cloth and please do not use any chemicals for cleaning.
Maintenance
1. Limited Warranty: One-year limited warranty from the date of purchase except vacuum tubes which are warranted for six
months.
2. Limited to original purchaser. This warranty is for the sole benefit of the original purchaser of the covered product, and may
not be transferred to a subsequent owner.
3. Conditions & Limitations. This warranty is subject to conditions and limitations, as follows. This warranty is void and
inapplicable if the product has not been used or handled other than in accordance with the instructions in the owner’s manual,
or if it has been misused, abused, damaged by accident or neglect, or in transport once in possession of purchaser, or the defect
is due to the product being repaired or tampered with by anyone other than Zhuhai Line Magnetic Audio Co., LTD or an
authorized Line Magnetic Audio Representative.
4. Remedy: If the product contains material, or manufacturing defects, it must be packed in original packaging and returned to
Zhuhai Line Magnetic Audio Co., LTD or an authorized Line Magnetic Audio Representative at his or her sole expense.
A returned product must be accompanied by a written description of the defect and the warranty card with an authorized
dealer’s stamp on which indicates the model and series number, the date of purchase, the name and address of the purchaser.
Zhuhai Line Magnetic Audio Co., LTD reserves the right to modify the design of the product and change the specifications
without notice or obligation to any person.
5. Miscellaneous. Any implied warranties relating to the above product shall be limited to duration of this warranty. This warranty
does not extend to any incidental or consequential costs or damages to purchaser. Our liability will be no more than the amount
you paid for the product that is the subject of a claim. This is the maximum amount for which we are responsible. This warranty
gives you specific legal rights. You may also have other rights which vary from country to country, state to state
Warranty Statement
Terms & Conditions:

08
Troubleshooting
Please follow the instruction in the manual in order to keep the DAC 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 reason.
Sometimes problems would be caused by the other related products and please have a check too on those connections.
Even doing so, if the problem still exists please contact with your local agent or our company.
Problem Cause Remedy
NO OUTPUT
Power cord is not well-connected
Main fuse is out.
Troubles of inner parts
or components
Please check the power cable connection or
power outlet connection
Replace with the same type and value fuse
Please contact with local agents or our
company.
NO signal input
Check the function of the sound source
Check the input selection and switch to the
proper input.
Sound field Positioning is
not so good.
Noise output
Ground of input signal cable is
open or bad contact of the input
signal cable
Components or circuits are
in trouble
Signal input cables or speaker
cables are wrongly connected
Replace the input signal cable with a
new one
Please contact with local agents or our
company.
Reconnect it as suggested in the manual
Line Magnetic logo is registered trademark of Zhuhai Line Magnetic Audio Co., LTD.
Copyright of Zhuhai Line Magnetic Audio Co., LTD. All Rights Reserved.
Power indicator
is OFF
Power indicator
is ON
Problematic USB playback
Audio output device of the PC
is wrongly set up. Choose the correct Output device.
Problem on USB Driver. Install the driver correctly.