Here is my optimisation guide for NW-A306/A307. Mine is Japanese uncapped version. I only use the device for offline playback, I do not use any online services nor streaming apps. Your needs may be different.
I use Universal Android Debloater Next Generation to uninstall apps from Android. I assume you have the application already installed on your PC. See
https://github.com/Universal-Debloater-Alliance/universal-android-debloater-next-generation/ for instructions.
Upgrade your DAP to the latest firmware 3.01.00 (Settings - System - System updates). Restart your DAP. Perform Factory reset (Settings - System - Reset options - Erase all data (factory reset).
1. Choose language. Tap "Start".
2. Read the EULA. Tap "Agree".
3. Read the Screen Lock security note. Tick "I agree". Tap "Next".
4. Don't connect to Wi-Fi now. Tap "Set up offline".
5. Tap "Continue".
6. Set up your Time Zone, current date and time. Tap "Next".
7. Disable all three options on this screen:
* Use location: "Off"
* Allow scanning: "Off" (no change)
* Send usage and diagnostic data: "Off"
Tap "Accept".
8. Set a PIN, tap "Next". If you don't want to use a PIN, tap "Skip". Tap "Skip anyway".
9. Set Auto Power Off timer. Choose your desired value. I choose 12 hours. Tap "Next".
10. Your DAP now starts to the default launcher. Choose your default Home screen. I choose Page 1. Tap "OK".
11. You are now on your Home screen. Swipe up to show installed apps. Launch the Settings app (
).
12. Scroll down. Tap "About device".
13. Scroll down. Tap "Build number" repeatedly until a pop-up "You are now a developer!" shows up.
14. Tap "Back".
15. Tap "System".
16. Tap "Developer options".
17. Enable "USB debugging". Tap "OK".
18. Use a USB cable to connect the DAP to your PC.
19. DAP: Tap: Use USB for: "File Transfer". Tap "OK".
20. PC: Start Universal Android Debloater Next Generation on your PC.
21. DAP: Tap "Allow" to allow USB debugging connection with your PC.
22. PC: You are on "Recommended" list in UAD-NG.
23. Choose all packages except
com.google.android.apps.nbu.files. This is the Files by Google app.
24. Click "Review selection (61)".
25. Click "Apply". UAD-NG uninstalls selected packages.
26. Switch from "Recommended" to "Advanced" list.
27. Choose all packages except
com.google.android.inputmethod.latin. This is the Gboard - Google Keyboard app.
28. Click "Review selection (37)".
29. Click "Apply". UAD-NG uninstalls selected packages.
30. Switch from "Advanced" to "Expert" list.
31. Choose
only packages
com.google.android.cellbroadcastreceiver and
com.google.android.cellbroadcastservice.
32. Click "Review selection (2)".
33. Click "Apply". UAD-NG uninstalls selected packages. There may be more packages that are safe to uninstall, I haven't tested that.
34. Switch from "Expert" to "Unlisted" list.
35. Choose
only packages
com.sony.songpal.mdr,
com.sony.walkman.DeviceHelpSiteJpn,
com.sony.walkman.launcherbookmarks,
jp.co.labelgate.moratouch.
36. Click "Review selection (4)".
37. Click "Apply". UAD-NG uninstalls selected packages. There may be more packages that are safe to uninstall, I haven't tested that.
38. PC: Close the UAD-NG application on your PC. Disconnect the USB cable.
39. DAP: On your DAP, you should still have "Settings" app runing on screen. If not, return to Settings - System - Developer options.
40. Disable "USB debugging".
41. Disable "Use developer options".
42. Restart your DAP.
43. After restart, launch
Settings app and disable unnecessary services.
44.
Network & internet
Internet
Wifi: OFF
Network Preferences
Turn on Wi-Fi automatically: OFF (no change)
Notify for public networks: OFF
Back. Back. Back.
45.
Connected devices
Connection preferences
Bluetooth
Use Blueetooth: OFF
Back.
Quick Share
Who can share (No one): OFF (no change)
Back. Back. Back.
46. Skip
Apps, we will return to apps later.
47.
Notifications
App notifications
Tap "Most recent", switch to "All apps".
Disable all except "Music" and "Settings".
Back.
Bubbles.
Allow apps to show bubbles: OFF
Back.
Notifications on lock screen
Don't show any notifications
Back.
Do Not Disturb
Turn on now
People
Messages
Choose "None"
Calls
Choose "None"
Allow repeat callers: OFF
Back. Back.
Alarms & other interruptions
Turn off all options
Back.
Display options for hidden notifications
Choose "No visuals or sound from notifications".
Back. Back.
Hide silent notifications in status bar: ON
Allow notification snoozing: OFF (no change)
Notification dot on app icon ON (no change)
Enhanced notifications: OFF
Back.
48.
Battery
Battery Care
Use Battery Care: ON
Back.
Battery Saver
Use Battery Saver: ON
Back.
Battery percentage: ON
Back.
49.
Sound
Default notification sound
Tap "None". Tap "OK".
Default alarm sound
Tap "None". Tap "OK".
Screen locking sound: OFF
Charging sounds: OFF
Tap & click sounds: OFF
Back.
50.
Display
Brightness level: move the slider to your desired level. I choose 75%.
Lock screen
Privacy
Choose "Don't show notifications at all"
Double-line clock: OFF
Wake screen for notifications: OFF
Back.
Dark theme: ON
Night light
Schedule
Turns on at custom time
Back.
Screen saver -> Use screen saver: OFF
Back. Back.
51.
Accessibility
Color and motion
Remove animations: ON
Back. Back.
52.
Security
Find My Device
Use Find My Device: OFF
Back. Back.
53.
Privacy
Show media on lock screen: OFF
App content: OFF
Show clipboard access: ON (no change)
Autofill service from Google
Use Autofill with Google: OFF
Back.
Ads
Delete advertising ID
Delete advertising ID
Back.
Usage & diagnostics: OFF (no change)
Back. Back.
57.
Safety & emergency
Emergency location service
Use Emergency location service: OFF
Earthquake alerts
Earthquake alerts: OFF
Back. Back.
58.
Passwords & Accounts
Passwords: Google
Tap "Password Manager" "gear" icon.
Offer to save passwords: OFF
Auto sign-in: OFF
Back. Back.
Autofill service
Tap "Google".
Choose "None".
Back.
Automatically sync app data: OFF
Tap "OK".
Back.
[To be finished. Thank you for patience.]
59.
Google
Tap the three dots in upper right corner.
Usage & diagnostics: OFF (no change)
Back.
Services on this device:
Ads: no change required, fixed by step 53
Autofill: no change required, fixed by step 58
Personalize using shared data
Device Contacts: OFF
Back. Back.
60.
System
Keyboard
On-screen keyboard: Gboard
Tap "Gboard".
Preferences
Show emoji switchkey: OFF
Back.
Privacy
Share usage statistics: OFF
Personalize for you: OFF
Improve for everyone: OFF
Delete learned words and data
Enter the code displayed on the line above.
Tap "OK".
Back. Back. Back. Back.
Date & time
Use 24-hour format: ON
Back. Back.
If you want use Google Play Store to install applications, you are now done. Restart your DAP.
If you want disable Google Play Store and Google Play Services, continue with next step.
You didn't uninstall Google Play Store (com.android.vending) and Google Play Services (com.android.gms) using UAD-NG. In my experience uninstalling these packages leads to boot-loop of the device, but we can disable it in Settings - Apps.
61. Return to
Settings - Apps
Tap "See all 8 apps". (The number may (?) vary)
Google Play Store
Force Stop
OK
Disable
Disable app
Storage & cache
Clear cache
Clear storage
Delete
Back. Back.
Google Play Services
Force stop
OK
Disable
Disable app
Force stop
OK
Storage & cache
Clear cache
Back
62.
Restart your DAP. You can re-enable Google Play Services and Google Play Store anytime if you need it.
