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Amplifier made of older Sony car stereo

Posted: Sat Nov 23, 2019 12:49 am
by Ino
Hi there! Glad to be here. I'm only do it myself in electronics in my spare time, therefore I'm far away from a beginner. However, that does not stop me to try to do things that are beyond me, solely because I enjoy it. These being said, please, don't dissapoint my ambition by saying that what I'm trying to do is beyond my capabilities.

All right. I'm trying to turn my past Sony MEX BT2700 stereo into an amplifier for a much lower end, cheap Chinese car radio, which I love for how it fits to the interior of my car, has a USB slot, Bluetooth, and does not make that annoying beep anytime I remove the key from ignition, as Sony does, and it cannot be set off on older than 2011 models.

Now, I found the post of someone who has done something like this, but the stereo that he used was different, more exactly the IC, it was slightly different than mine.

What I've got is a TDA8588AJ/R1Cu, whilst his was a Toshiba TA8272H. Here's the link to the Instructables website where he posted his masterpiece: ... amplifier/.

He has eventually separated all the components that were necessary for the IC to work, conform to the schematics of the IC that he has found on the Internet (he's also an engineer, far more superior to me in terms of diy electronics), and lastly he has cut the rest of the board, leaving untouched only a third of it, surrounding the integrated circuit, at the back of the stereo device. He said that he has managed to add a jumper link on the stand-by pin of the IC, that before it was only powered by the micro controller when the radio was on, before he "injected" signals direct to the input pins, and then he redirected the audio from the audio-out connectors to feed audio to the amp into the couple of RCA outputs on the back, and audio came out of the speakers.

The idea is that his IC seems to have, conform to the sheet, a stand-by more, which conform to the sheet of my IC, mine doesn't.

I'm afraid to just cut the board, and hope that it will work, as my knowledge of electronics is far weaker, to start tracing the pathways ot each pin and where it should go, in order to be able to make sure that I separate the necessary part of the board, from the unnecessary one, which contains the microcontroller, the thing that will keep the amplifier from working at all, until the face of the device is put on, as a normal radio device.

My questions are:

1) What the connections would look like, in order to use this stereo as an amplifier, should I put the RCA out L and R of my little Chinese radio, into the RCA in L and R of the Sony stereo that I intend to use as amplifier only?

Of course, I will wire the Sony as normal, into the dashboard, and the signal radio I will wire in parallel to the Sony, only the plus and the minus, and the yellow and orange wires.

2)What should I have in mind if I cut the Sony board, and I get no signal into the speakers? Of course, I will make sure that along the cut no copper chips will mix with each other or with solder chips, so as to avoid any short circuits.

However, if I get no signal, should I try to wire any pin of the amplifier to the plus directly? Or to the plus coming from the ignition?

I have an image in mind of what I should or should not have to consider, but my knowledge of 101 electronics lacks much content, and I can only put things together, on the go.

Thanks for any insights, and helpful opinions. Nevertheless, no discouraging opinions are welcome, LOL.


Re: Amplifier made of older Sony car stereo

Posted: Wed Nov 27, 2019 4:54 pm
by David
I have just had a casual look at the TDA8588AJ/R1Cu, and it seems to be a very powerful chip. It should certainly provide as much output as you will ever need. Try hooking up the little Chinese radio outputs to the Sony inputs. If you are lucky, that may do most, if not all, of what you want to do.

I don't see why you want to cut up the Sony board. If it works, don't fix it! It will have the appropriate heat sink (very necessary!) and suitable surrounding components such as capacitors and suchlike.

Use Google and get a data sheet for your chip, and study it! When you are au fait with its workings, experiment!

Hope this helps

Re: Amplifier made of older Sony car stereo

Posted: Wed Dec 11, 2019 11:48 am
by JesseNib
@David before the transformation how did the Sony deck do? Would you recommend it?

Sorry for being off topic. I'm looking for a car stereo for a while now. And can't make up my mind. At the moment I'm thinking about Sony xav-ax5000 but it's not set in stone. The net is filled with hyped up reviews that are useless.

This is why I'm asking you that maybe I can get an unbiased opinion from someone who's actually has something similar. Now I might've bought the unit a week ago. I've came across a different blog where the writer is critical of all brands. This Sony receiver review put me on the fence. I mean does it work with Android auto or it doesn't? What about that album art is it in existent?

2 cents?

Re: Amplifier made of older Sony car stereo

Posted: Fri Jan 24, 2020 4:14 pm
by David
Hi. I do not have a Sony radio in my car, and what I was trying to say is that I can't give you chapter and verse about modifying any equipment other than by general comments. I am happy to give you as much help as I can, but I cannot do much in the way of very detailed comment where I have no experience of a particular manufacturer's device - sorry.

If you want to go ahead with the little Chinese radio feeding into the Sony idea, then go ahead -just do it! Get a circuit diagram of the chip and what is around it if at all possible - that will be a huge help. Be aware of the drain on the car's electrics and so on. If you can get sound out by hooking up the output of the radio to the Sony, then that is a very good start! Use that as a jumping off stage into the wonderful world of electronics!