Technics EAH-AZ70 (Japan) Bluetooth Headphones Teardown

ID: 135886

Description: A look inside the Technics EAH-AZ70 (Japan) /...

Steps:

1. Features:
2. Highest Level of Dual Hybrid Noise Cancelling. Multiple MEMS microphones
3. Graphene coated PEEK diaphragm speaker for smooth, clean, and elegant sound
4. Stable Connection in crowed areas
5. Excellent Quality Call Sound
6. Approximately 6.5 hours of playback, and up to 20 Hours of use with charger
7. Bluetooth® 5.0
8. Capacitive touch sensor control

9. What is in the box
10. Headphones / Charging Case
11. USB 'C' Cable
12. Headphone rubber tips for different sizes of ears
13. User's Manual

14. Charging case with headphones
15. Close up view of headphones

16. Side views of Headphone
17. Charger Interface
18. USB Interface
19. Speaker Sound Port
20. MEMS Microphones
21. Speaker Vent
22. Vent Port
23. Speaker Spatial Vent Port

24. View of Headphone with rubber ear piece removed
25. Vent Port

26. Since the Technics Headphone enclosure is glued together, the only way in was to cut into the headphone.
27. This is a destructive teardown
28. A Razsor knife was use to cut into the Technics headphone along the seam in the headphone. Then a Jimmy Tool was used to open up the headphone. Tweezers and a Pick Tool were used to removed the electronics from the enclosure
29. Once opened, we get our first look at the inside of the headphone
30. Double sided foam tape was used to hold the main the PCB to the Battery and to the Touch Sensor / Antenna PCB. This foam tape had to be cut free. Then Denatured Alcohol was used to remove the foam tape glue from the PCBs and Battery
31. Double Sided Foam Tape

32. Opening up the headphone, we can see the main PCB, Battery, Speaker, etc
33. Battery
34. Main PCB
35. Speaker
36. Speaker Sound Chamber
37. Touch Sensor and Antenna

38. At first, I wasn't sure about the solder balls. Then I realized they were used to anchor the USB and Power Interface pins on the outside of the Headphone to the internal circuit board.
39. I had to used a solder iron to remove the solder balls, so that the internal interface circuit board could be removed. I had to also remove solder from the speaker wires to free up the internal circuit board.
40. Internal Circuit Board that interface Power and USB to the Headphones

41. The internal circuit board was also attached a MEMS Microphone that appeared to be monitoring the Speaker Chamber of the Headphone, since it was faced in
42. I had to remove the outside panel with 'R' on it with a Razor Knife to free the MEMS Microphone. Once the MEMS Microphone was freed, the interface board circuit could be pulled out
43. USB and Power (Charger) Interface
44. Sound Ports
45. Internal Circuit Board that interface Power and USB to the Headphones
46. MEMS Microphone from plastic collar in the Headphone
47. MEMS Microphone separated from the Interface Circuit Board when removed from the side of the Speaker Chamber

48. There was not much to see on the internal interface board top side or bottom side. The was one IC component that could not be crossed. If you happen to know the component, please leave a comment below
49. Unknown Component

50. Full Sensor Flex/Charging PCB IC Identification:
51. You may need to enlarge the picture to view the text.

52. Next the Speaker sound chamber cover was removed with the use of a Pick Tool and Tweezers. A Razor Knife was used to cut the glue holding the speak in place
53. The speaker had no identifiable markings
54. With Speaker removed, we can see the sound chamber and sound ports

55. Closeup view of the Battery
56. Li-Ion 3.7V, 0.32Wh
57. The battery appears to be from VDL Electronics Co., Shenzhen, China

58. Closeup view of the Antenna/Touch Sensor side of the Main PCB
59. DSP Group - C2A1A Hybrid Active Noise Cancellation (ANC) Codec and Audio Digital Signal Processor (DSP)
60. 651DF1M9 - Could not cross part number, but during a web search found out that it may be an integrated battery management IC
61. W25Q32JWUUIMTR- SPI FLASH 32Mb
62. MEMS Microphone Port

63. Closeup view of some of the components on the Antenna/Touch Sensor side of the Main PCB
64. DSP Group - C2A1A Hybrid Active Noise Cancellation (ANC) Codec and Audio Digital Signal Processor (DSP)
65. Winbond-W25Q32JWUUIMTR SPI FLASH 32Mb
66. 651DF1M9 - Could not cross part number, but during a web search found out that it may be an integrated battery management IC

67. Battery side close up view of the Main PCB
68. AIROHA AB1552 - ARM Cortex M4/Bluetooth 5.0 Dual Mode
69. 913 MPS1 MEMS Microphone. The Headphone uses three MEMS microphones with this part number
70. Could not cross the part number. If you know the part, please leave a comment below. The 2D bar code on the part reads as STM9135G15JAS011
71. Crystal Oscillator
72. Unknown component. Labelled B2A. Please leave a comment if you happen to know this component
73. Unknown component. Labelled SV4CP 240. Please leave a comment if you happen to know this component. Separated from PCB during teardown

74. Closeup view of some of the components on the Battery side of the Main PCB
75. AIROHA AB1552 - ARM Cortex M4/Bluetooth 5.0 Dual Mode
76. 913 MPS1 MEMS Microphone. The Headphone uses three MEMS microphones with this part number
77. Could not cross the part number. If you know the part, please leave a comment below. The 2D bar code on the part reads as STM9135G15JAS011
78. Unknown component. Labelled SV4CP 240. Please leave a comment if you happen to know this component. Separated from PCB during teardown

79. Closeup view of top and bottom side of the Touch Sensor Flex PCB and Antenna

80. Full Main PCB IC Identification:
81. You may need to enlarge the picture to view the text.

82. Predicted Block Diagram of the Technics EAH-AZ70 (Japan) Bluetooth Headphones:
83. You may need to enlarge the picture to view the text.

84. Teardown Exploded View of the Technics Headphone