Amplifier Upgrade - Replaced TDA 7851 with Pioneer MOSFET PA2030A on Eonon GA2171S

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Kwen

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Nov 10, 2006
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Montreal
Unless you did a blind A/B testing, or use a calibrated microphone to measure frequency response, anything you hear can be procebo.

Anyhow, I saw a post somewhere where someone added capacitors for bootstraping and what not, that would most likely improve the sound vs swapping the IC alone.
 
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marchnz

Senior Member
Nov 26, 2012
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Unless you did a blind A/B testing, or use a calibrated microphone to measure frequency response, anything you hear can be procebo.

Anyhow, I saw a post somewhere where someone added capacitors for bootstraping and what not, that would most likely improve the sound vs swapping the IC alone.
It also gave the car another 100HP....:)

Yes, and according to the datasheet, the gain ID so little it is unlikely to be perceived. A bit like oxygen free cable.
 

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    Hi everyone, I came across a mod on a russian forum and decided to give it a try myself.
    Yeah, because if you see something on a Russian forum, you absolutely must do!!!!

    The original amplifier chip is a TDA7851A and I have successfully replaced it with a Pioneer MOSFET PA2030A

    There isn't a decent datasheet of the PA2030A but from what I have read it has a higher power output of approx 35W RMS and 60W MAX at 4 ohms. The TDA7851A is 28W RMS and 48W MAX at 4 ohms.
    So here is the problem with what you did.
    The PA2030A is **NOT** 60W. Its 50W.
    The reason you can't find a "decent datasheet" is because it is NOT manufactured by pioneer. It is, in fact, manufactured by STMicroelectronics. It is, in fact, a TDA7850A that has been "rebadged" -- just like they do with cars where, for example, Nissan Frontier was (for a while) being sold as "Suzuki Equator". They even go so far as to use the same "A" suffix. PA2030 = TDA7850, PA2030A = TDA7850A. This is its datasheet: https://www.st.com/resource/en/datasheet/tda7850a.pdf

    So here is the thing..... TDA7388.
    42 or 45 x4. People have been replacing THOSE with either TDA7850/1 or PA2030. Reason? Give you an extra 5W. Enough to make a difference? Heck no, but more watts!!!

    I'm really sorry to tell you that any difference in sound quality is purely a figment of your imagination and nothing more. You have, in fact, replaced your amplifier chip with one that is very nearly identical.
    3
    Should I stay with my tda7851L or do I put pioneer pa2030a?

    Missed the items suggesting there's no major benefit, use an external amp.
    2
    Hi everyone, I came across a mod on a russian forum and decided to give it a try myself.

    My unit:

    Eonon GA2171S - MTCE KLD PX5 with 4GB RAM, DSP built in.

    The original amplifier chip is a TDA7851A and I have successfully replaced it with a Pioneer MOSFET PA2030A

    There isn't a decent datasheet of the PA2030A but from what I have read it has a higher power output of approx 35W RMS and 60W MAX at 4 ohms. The TDA7851A is 28W RMS and 48W MAX at 4 ohms.

    Replacement wasn't easy!
    1) Disassemble the unit to remove the main board. My unit was especially bad because they used an adhesive silicon glue on every connector which I had to cut to free the parts.
    2) Identify the amp chip - it is between the rear headers
    3) Remove the old amp chip - I bent the amp chip to snap off the pins so that I could de-solder it easier. I tried with solder wick, but it wasn't working well. In the end I melted each pin and removed with pliers, and then went along each hole and used a solder sucker.
    4) Fit the new amplifier chip - ensure it sits in the correct position to attach to the chassis. I found this was easiest by holding the chassis in place while I made the first few solder joints on the board
    5) Solder all the pins carefully - You will want to use a fair bit of heat to ensure you don't get dry joints. Visually inspect when done to make sure you don't have any shorts.
    6) Reassemble the unit
    7) Test!

    At this stage I would say the sound quality has improved noticeably but it isn't a huge change. The highs seem a little clearer and there does seem to be a bit more punch when pushing the bass too. I'm still trying to find the ideal DSP and EQ settings. With Flat EQ it sounds terrible as always so make sure you tune it well!

    I sourced the part from WWW.UTSOURCE.NET
    2
    SO you are BOTH wrong.. The ST TDA7850A is a 27 PIN package as the Pioneer and those other variants are all 25 pin and are NOT compatible. The pioneer could very well be the TDA7850 as it IS pin compatible with the other package the OP listed. NOW lets look at the situation at hand and see what we COULD benefit from a swap of our Flexiwatt25 Amplifier IC.

    ST was kind enough to provide us a database of pin capatible ICs. We are going to want to look at ONLY the 'Y' designation.
    LINK- ST SITE, SEARC,H, sgaudiopow0315.pdf

    NOW looking at this document provided by ST they have a few new variants that we could take advantage of. They have the lowest THD 0.15 IIR down to .007 TYP.
    Also a higher output and GSM blocking internally. They are available in the 25 pin configuration and will work down to 6V (designed for automanufactures that are stopping engine cylinders for fuel mileage)

    In this list here is the ICs that I would look at as the highest quality and PIN compatible.
    STPA001,2,3,8 as they are all a little different. you want 25 pin VERTICAL. they have much better THD and a little boost in output. 2 Ohms capable also

    sticking with the TDA line of ICs I would look at the MOSFET series and the following again with much better THD.
    TDA7560, TDA7850

    Hope this clears the air. DO NOT use the suffix A ICs as what I see they are all the 27 PIN Flexiwatt package

    ---------- Post added 7th March 2019 at 12:01 AM ---------- Previous post was 6th March 2019 at 11:58 PM ----------

    the noise as you say could be GSM noise that ST targetted to reject in these later chips FYI
    1
    This is the PA2030A pin scheme from a pioneer service manual, FYI