How to Assemble “otomatsu” Portable Headphone Amplifier

If you have any question please contact by e-mail to:otomatsu@aurorasound.jp- Adopt High Performance, High Fidelity OPAMP LME49710 + High Performance, Low distortion Buffer IC LME49600- The amplifier‘s overall gain can be adjusted and support 16Ω to 300Ω impedance characteristic of any headphones.
- Easy build and flexibility for upgrade.
- Portable case easy to carry, Thumb screw fasten system to make exchange battery easier.
- External DC input by AC power adaptor.
C13, C14 ElectricCapacitor
Gold 100uF 25V x2Long lead is +, short -2. Start soldering the low profile parts first then the high one.
At the first registers, second IC socket, third Ceramic
capacitors, fourth IN/OUT jack……… last Electriccapacitors.

++--

C11,C12 ElectricCapacitor
Black 330uF 16V x2Long lead is +, short -1. Please check that all parts are in the box and accounted for.

C3,C4,C5,C6,C7,C8 ,C9,C10 x8Blue 0.1uF Ceramic Capacitor
No +/- polarity

C1,C2 x2 Red
3.3uF Film Capacitor
No +/- polarity

Turn the PCB over and solder. Need to cut out lead wire with anipper
LEDx1
Ling lead is +, Short --3. Solder the low profile parts, See left bottom picture
4. Now solder the high profile parts+

Print Circuit Board x1
IC3,IC4 LME49600 x2 are pre-soldered
Pin No.1 is floating

All parts list
5. NOTE : You will need to solder jumper wire for power SW

as the illustrated in the following picture. Use the cut out leadof the registers.

6.. Insert OPAMP into socket and mindful of the orientation

-+

OUPUT

INPUT
All Parts are soldered on the PCBotomatsu Nov. 2012

How to Assemble “otomatsu” Portable Headphone Amplifier
Audio performance

AMP gain adjust registers
This kit’s default gain is x11 for low sensitivity high-end
headphones. However some headphone, for instance,
canal type earphones or high sensitivity type, x11 istoo much.
In this case, you can adjust the gain down to x5.7 or x2 byexchange R3 and R4.

Frequency response 10Hz - 60kHz -1.5dB
THD+N 0.05% @32Ω lord

Left bottom 10Hz base clean sine waveMiddle
20kHz treble same level of 10Hz
Right bottom THD+N is very good level , 0.05%

R3 and R4 default value is 10kohm, Gain is x11.
Adjust gain x5.7 by 4.7k ohm.
回路図
SCHEMATICS

Adjust gain x2 by 1kohm

BAT.+

R13 10k
DC+BAT -SW1DC+LED1Gain formula(R1 +R3) / R1 = GAIN

R11 2k

C13 100u 25V

Color code of gain adjust registrars

DCDC JACK4.7kΩ x2

YePuBlBr Br(1k + 10k) / 1k = x11(1k + 4.7k) / 1k = x5.7
( 1k +1k ) / 1k = x2

GND
C14 100u 25V

C3 0.1uC7 0.1uVR1
C1 3.3u

3IC1LME49710
NE5534A+2-6C11 330uF 16V

241R5 100k

DC jack fixed on the back panel, then wiring as the following picture.

R9 4.7k
C9 0.1u

X1 INPUT JACKX2 OUTPUT JACKCut the red wire of the battery snap jack which is 1 inch shorter than black.
In order to protect soldering points, all wires go through the hole of PCB as shown in the below left picture.
The AC adaptor can be used under DC24V, and center plus type.
The battery disconnects at DC jack insertion.

R2 1kC4 0.1u

R4 10k
C8 0.1uC2 3.3uF
R6 100k5+

LME49710
IC2NE5534A

3+2-6C12 330uF 16V

2413+

VR17Aluminum case + Plastic Panels
Panel sticker
Volume knob, DC jackThumb screw for back panel x2
Hexagon socket set screw x2
L-Wrench

R7 9.1 1W

34IC3
LME49600
LME49600

C5 0.1u

4Portable caseR12 2kR3 10k

5BrblblBr Br

10k
4.7k
1k

71k x2

Default
Case ofCase of

R1 1k

IC4LME49600
LME49600

R8 9.1 1W
R10 4.7k

C6 0.1uC10 0.1u

otomatsu HPA-X
OTOMATSU
HPA-X
Rev.4.0
Rev3.1Aug.2012
Sep/20 2011
Copy
RightShinobu
Copy
Right
AurorasoundKaraki, AurorasoundBlackRed

Next step for upgrade
Exchange OPMAP ICs to upgrade audio performance to enjoy the improved
sound characteristic by each OPAMP ICs.

Hexagon socket set screw fixed as the following picture
Single type LME49710, LME49990, OPA627A, LT1115, are recommended

otomatsu Nov. 2012