Comparison between the two models (301 protocol and 307 protocol) Desai Severi RD45. I hope there will be experts to guide them.

  6
 September 15, 2024
Some time ago, I heard that someone used the RD45 of the 301 protocol on a Sega car and successfully revised the protocol, but he himself was not sure how it was modified. I also watched his operation video. I can really use all the functions of the 301 RD45 perfectly on Sega. The only thing is that the sound cannot be transmitted when making a phone call, and even the address book display and Bluetooth song name display are normal. Today, I had nothing to do, so I took apart the two RD45s in my hand: Desai Sev RD45 301 agreement model and Desai Sev RD45 307 agreement model and compared them.
After comparison, I was really surprised. The layout and circuit design inside were almost identical. Except for slight improvements to the circuit board, there were no other changes. This makes it better to understand why someone can use 301 ‘s RD45 on Sega by modifying parameters. Not much to say about the above picture:

307 protocol RD45 panel

307 protocol RD45 version number, this CD is relatively old, about 12 years old car demolition CD. The sound quality is one level higher than the common RD43. However, the Bluetooth address book does not display it, and the sound quality of the Bluetooth phone is relatively poor. After all, it is a long time.

307 protocol RD45 side

307 protocol RD45 side

307 protocol RD45 back

307 protocol RD45 bottom

307 protocol RD45 panel interface

307 protocol RD45 circuit board back

307 protocol RD45 chip feature

307 protocol RD45 circuit board front

307 protocol RD45 chip feature

307 protocol RD45 Bluetooth module

307 protocol RD45 power amplifier chip: TDA7563B capacitor: 4700uf.

The version number of the 307 protocol RD45 circuit board, you can clearly see the operational amplifier model: 4558I.

301 protocol RD45 panel

301 protocol RD45 version number. This CD is relatively new. It is a new version in the past two years. It has been optimized in aspects such as Bluetooth phones.

301 protocol RD45 side

301 protocol RD45 back

301 protocol RD45 interface

301 protocol RD45 front panel circuit

301 protocol RD45 circuit board back

301 protocol RD45 chip feature

301 protocol RD45 circuit board front

301 protocol RD45 chip feature

301 protocol RD45 chip feature

301 protocol RD45 chip feature

A close-up of the 301 protocol RD45 chip. I forgot to take a close-up of the power amplifier chip. It is still: TDA7563B capacitor: 3300uf.

The version number of the 301 protocol RD45 circuit board, you can clearly see the model number of the operational amplifier chip: 4558I.
If any expert sees this post, please help me think of a way to apply the RD45 of the 301 protocol to the 307 protocol model. I believe many people are waiting for experts to solve this problem.