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

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ciccimatt

Member
Nov 10, 2016
17
4
This is the PA2030A pin scheme from a pioneer service manual, FYI
 

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jerrymh

Senior Member
Feb 8, 2016
80
7
Do this works to clean the dity audio on this unit? What is the benefit on changing the amplifier chip?
 

96carboard

Senior Member
Jul 17, 2018
958
585
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

If you're worried about 25 vs 27 pin package configuration, then you're completely missing the point, which is that these chips are **all the same and made in the same facility, but given different number of pins and/or manufacturer branding**.
 

antbox530

New member
Jan 3, 2020
2
1
After a lot of research, it appears the PA2030A is actually a TDA7384/7486/7388 or a closely built proprietary product.

The STPA003 looks to be the best flexi-watt 25 amplifier out right now, but, unless you have 2 ohm speakers or a car with start-stop (Hybrids), it wouldn't be worth your time and the TDA 7850 being the same without the low voltage operation.

All of the TDA chips that weren't 2 ohm stable and close to the PA2030A specs would be a slight downgrade from the 7851. The power levels should be virtually indistinguishable from one another, but the 7851 is 2 ohm stable (can handle more power if you have 2 ohm speakers (an additional 24 watts peak per channel) and slightly worse THD (distortion).

The PA2030A is not 2 ohm stable according to Pioneer and the 7384/7386/7388 looks almost identical to the specs listed in the Pioneer service manuals.

The 7384, 7385, 7386, and 7388 are all listed on Pioneer's parts site on older radios. It looks like they had SM "build" them the PA2030A for newer radios, but it's virtually the same with a different logo.

Here are the specs listed for the PA2030A from pioneer's repair manual:
Maximum power output: 50 W × 4
Continuous power output 22 W × 4 (50 Hz to 15 000 Hz, 5 % THD, 4 Ω load, both channels driven)
Load impedance 4 Ω (4 Ω to 8 Ω allowable)
CEA2006 Specifications
Power output 14 W RMS × 4 Channels (4 Ω
and 1 % THD+N)
S/N ratio 91 dBA (reference: 1W into 4 Ω)
 

marchnz

Senior Member
Nov 26, 2012
5,332
1,155
NZ
After a lot of research, it appears the PA2030A is actually a TDA7384/7486/7388 or a closely built proprietary product.

The STPA003 looks to be the best flexi-watt 25 amplifier out right now, but, unless you have 2 ohm speakers or a car with start-stop (Hybrids), it wouldn't be worth your time and the TDA 7850 being the same without the low voltage operation.

All of the TDA chips that weren't 2 ohm stable and close to the PA2030A specs would be a slight downgrade from the 7851. The power levels should be virtually indistinguishable from one another, but the 7851 is 2 ohm stable (can handle more power if you have 2 ohm speakers (an additional 24 watts peak per channel) and slightly worse THD (distortion).

The PA2030A is not 2 ohm stable according to Pioneer and the 7384/7386/7388 looks almost identical to the specs listed in the Pioneer service manuals.

The 7384, 7385, 7386, and 7388 are all listed on Pioneer's parts site on older radios. It looks like they had SM "build" them the PA2030A for newer radios, but it's virtually the same with a different logo.

Here are the specs listed for the PA2030A from pioneer's repair manual:
Maximum power output: 50 W × 4
Continuous power output 22 W × 4 (50 Hz to 15 000 Hz, 5 % THD, 4 Ω load, both channels driven)
Load impedance 4 Ω (4 Ω to 8 Ω allowable)
CEA2006 Specifications
Power output 14 W RMS × 4 Channels (4 Ω
and 1 % THD+N)
S/N ratio 91 dBA (reference: 1W into 4 Ω)

From earlier discussion, there was little to be gained from replacing the IC and the pioneer is most likely a process of manufacturer "binning".

If more power is wanted, suggest installing external power amps.
 

antbox530

New member
Jan 3, 2020
2
1
From earlier discussion, there was little to be gained from replacing the IC and the pioneer is most likely a process of manufacturer "binning".

If more power is wanted, suggest installing external power amps.
Was trying to inform others that might be looking this up in the future that no chips should be replaced by the PA2030A unless broken. It is a lateral move for the TDA7388 and a downgrade for the rest as you lose 2 ohm capability. Also that if you have 2 ohm speakers, you cannot use the PA2030A or TDA7388 without issues.

If you have the TDA7454, TDA7560, TDA7850, or TDA7851F you can pick up around an additional 80 watts RMS by switching to 2 ohm speakers if you currently have 4 ohm speakers, which would be right around a 3dB increase, which should be noticeable to most people.

Or, in my case, I have a unit with the TDA7388 and had sound issues because I have 2 ohm speakers, so I swapped to the TDA7560 to fix it.
 
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pir8man

Senior Member
Nov 25, 2007
308
79
I am curious if anyone changed to STPA003 or STPA008. Both add GSM noise immunity.
I replaced my TDA7388 due to failure, to a TDA7850 that I had spare. But now I am thinking of changing again just to get GSM noise blocking.

I also understand that modding in a ADAU1401 DSP would reduce the background noise due to the better DAC. Any idea which path is best to reduce the background noises?
 

96carboard

Senior Member
Jul 17, 2018
958
585
I am curious if anyone changed to STPA003 or STPA008. Both add GSM noise immunity.
I replaced my TDA7388 due to failure, to a TDA7850 that I had spare. But now I am thinking of changing again just to get GSM noise blocking.

I also understand that modding in a ADAU1401 DSP would reduce the background noise due to the better DAC. Any idea which path is best to reduce the background noises?

I can't think of a reason why changing the DAC would have any impact on GSM noise, except if in doing so, you are bypassing or eliminating a large portion of unshielded analog wiring. The issue with amplifiers and GSM noise is that the wiring before the amplifier becomes an antenna, and that is amplified by the amplifier and dumped out to the speakers.

Before going and changing parts, the first thing I'd suggest you try is to actually build an RF shield for the pre-amp analog wiring.

You can use electrically conductive tape like this; https://www.amazon.com/TitanRF-Faraday-Tape-High-Shielding-Conductive/dp/B07CRLCGCH
Note: You don't want to short out the board though, so first you want to put down a layer of something NON-conductive, like a sheet of plastic stuck down by electrical tape, then lay the conductive tape over THAT. And don't forget to connect the conductive tape to GND.

Make sure you shield ALL of the analog wiring, including the amplifier's legs.


My board design uses STPA003 and has top-surface-layer analog signal traces that run about 2 inches between the DACs and the amplifier, and I've *never* heard any GSM or other noise. HOWEVER, my cell provider doesn't use GSM frequencies. Still, I'm sure that I've had passengers with GSM band service providers. Also note that I don't have my board in a metal box, so there is no RF shielding on it at all. So I'd say that if the shielding option doesn't work adequately, the STPA003 would. Just make sure you are aware of how the pinouts compare.

https://www.aprax.tk/auto/
 

pir8man

Senior Member
Nov 25, 2007
308
79
I can't think of a reason why changing the DAC would have any impact on GSM noise, except if in doing so, you are bypassing or eliminating a large portion of unshielded analog wiring. The issue with amplifiers and GSM noise is that the wiring before the amplifier becomes an antenna, and that is amplified by the amplifier and dumped out to the speakers.

Before going and changing parts, the first thing I'd suggest you try is to actually build an RF shield for the pre-amp analog wiring.

You can use electrically conductive tape like this; https://www.amazon.com/TitanRF-Faraday-Tape-High-Shielding-Conductive/dp/B07CRLCGCH
Note: You don't want to short out the board though, so first you want to put down a layer of something NON-conductive, like a sheet of plastic stuck down by electrical tape, then lay the conductive tape over THAT. And don't forget to connect the conductive tape to GND.

Make sure you shield ALL of the analog wiring, including the amplifier's legs.


My board design uses STPA003 and has top-surface-layer analog signal traces that run about 2 inches between the DACs and the amplifier, and I've *never* heard any GSM or other noise. HOWEVER, my cell provider doesn't use GSM frequencies. Still, I'm sure that I've had passengers with GSM band service providers. Also note that I don't have my board in a metal box, so there is no RF shielding on it at all. So I'd say that if the shielding option doesn't work adequately, the STPA003 would. Just make sure you are aware of how the pinouts compare.

https://www.aprax.tk/auto/

That is correct. The DSP mod calls for removing the analog sound processor chip and replaces all sound processing from digital/analog sources through the new DSP then on to the amplifier. Some modders are feeding direct to RCA(external amplifier), others are feeding back to the built-in amp chip.
I went ahead and ordered the faraday tape. I was thinking about getting some anyway.

Would there be any benefit to pulling the mainboard and shielding the backside as well?
If so, having the mainboard removed, I might as well swap the amp chip anyway. For me, removing the HU and mainboard take more time than swapping the amp chip.

Reading up on this... The backside is a ground plane for EMI/RF blocking. That saves me some trouble.
I think I will use electrical PVC tape as a backing to the copper tape. Hopefully that will get better shielding for each chip I cover and still protect from shorting..

EDIT:
I did 2 layers of the copper tape shielding and it greatly reduced hearing of my HU processing noises. I then added 2 more layers of copper tape to remove the remaining noise. Again the processing noises were reduced. There is still slight processing noises when installing an app or copying a file, but I have to have the car as quiet as possible (engine off, windows up) to hear it now. I will probably add another couple layers the next time I am in my HU for some reason.
 
Last edited:

An92

Senior Member
Oct 29, 2013
141
8
I have noises of electronic noise especially when I use USB ports, I tried to replace the 3300uf capacitor with a 10000uf one, but the noise has increased. I can't solve it in any way.
Is there a possibility that Chinese radios mount clones of tda 7851l, since there are many Chinese clones of this chip or others ??
 

marchnz

Senior Member
Nov 26, 2012
5,332
1,155
NZ
I have noises of electronic noise especially when I use USB ports, I tried to replace the 3300uf capacitor with a 10000uf one, but the noise has increased. I can't solve it in any way.
Is there a possibility that Chinese radios mount clones of tda 7851l, since there are many Chinese clones of this chip or others ??

Its not the power amp. Noise enters well before, is preamplified and then power amplified. If others had success increasing the value of the main reservoir capacitor, it may be a coinicidence, or there noise might have been car generated, entering the head unit.

The issue is poor design; lack of powersupply decoupling and internal noise suppression. Internally generated noise enters the audio path. Another issue is liberal use of glue which becomes slightly conductive with age. Ive mentioned both of these a number of time now.

No software upgrade will solve this. It is a hardware design issue.
 
Last edited:

An92

Senior Member
Oct 29, 2013
141
8
Its not the power amp. Noise enters well before, is preamplified and then power amplified. If others had success increasing the value of the main reservoir capacitor, it may be a coinicidence, or there noise might have been car generated, entering the head unit.

The issue is poor design; lack of powersupply decoupling and internal noise suppression. Internally generated noise enters the audio path. Another issue is liberal use of glue which becomes slightly conductive with age. Ive mentioned both of these a number of time now.

No software upgrade will solve this. It is a hardware design issue.

I tried to insert special filters in the power supply of the unit, but I have not solved it
Do you recommend removing glue?
I ordered the tda7851L chip from arrow usa, I think it is among the official sellers,
I have a doubt that Chinese units mount good fake tda audio amplification chips, as they are found a lot in China.
 

An92

Senior Member
Oct 29, 2013
141
8
Its not the power amp. Noise enters well before, is preamplified and then power amplified. If others had success increasing the value of the main reservoir capacitor, it may be a coinicidence, or there noise might have been car generated, entering the head unit.

The issue is poor design; lack of powersupply decoupling and internal noise suppression. Internally generated noise enters the audio path. Another issue is liberal use of glue which becomes slightly conductive with age. Ive mentioned both of these a number of time now.

No software upgrade will solve this. It is a hardware design issue.

I have important news.
I tried to connect the dashcam usb by connecting only the 2 data PINs on the rear usb port of the unit, and instead the + is - (power supply) of the dashcam usb on a charger for 12v cigarette socket of the car, and also on the front usb port , everything works, the loud rustling that was heard when I used USB devices connected to the unit and almost gone, the minimal rustling that this unit has
Finally!!!!

Now I have some SOLUTIONS, I would like help from you to choose the best one.
My chip that manages USB on my px3 klyde mtcd / e unit is a gl850g, model HH 28 PIN rectangle (NO square)

Where can I get the PIN + and - of the usb ports ??

Hypothesis 1:
I take from the front USB port, connecting in parallel the 3 ports, 1 front and 2 rear, but I am afraid that by connecting multiple devices something could burn.

Hypothesis 2:
I buy a 12v to 5 volt transformer and connect the +/- here, I take the current from the machine, but I would like everything to work when the radio is on, so it is born:

Hypothesis 3:
I find 5v voltage on the unit's mtcd and connect the rear USB port PINs here, maybe it could increase the noise, or

Hypothesis 4:
I find 12v voltage on mtcd of the unit able to maintain the current for the 12v-5v transformer, and from there bring current to rear usb ports bypassing the original power line of the usb ports, but also here it could increase the noise around the audio unit

Can you advise me, thank you
 

ELCouz

Member
Sep 7, 2018
32
4
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

That didn't fix the background noise doesn't it?
 

marchnz

Senior Member
Nov 26, 2012
5,332
1,155
NZ
That didn't fix the background noise doesn't it?

Probably different issue, mixed because in true xda form, this thread has been hijacked by off-topic posts related to "audio noise" and not the OP topic "Amplifier Upgrade - Replaced TDA 7851 with Pioneer MOSFET PA2030A" The Audio Power Amp is not the root cause.
 
Last edited:

An92

Senior Member
Oct 29, 2013
141
8
Yes, sorry, I don't want to go off topic, but I'm trying to solve, meanwhile today the tda 7851l chips arrive, ordered from an American supplier, certainly original, I see you replace the one originally present on my unit, given the many chip clones in China, I wouldn't be surprised if they had fake, even good, chips at the factory
 

marchnz

Senior Member
Nov 26, 2012
5,332
1,155
NZ
Yes, sorry, I don't want to go off topic, but I'm trying to solve, meanwhile today the tda 7851l chips arrive, ordered from an American supplier, certainly original, I see you replace the one originally present on my unit, given the many chip clones in China, I wouldn't be surprised if they had fake, even good, chips at the factory

Zero to do with noise though. Also, there's very little to gain power wise replacing the power amp; this has been well proven.

Note, the noise is present on the rca outputs, that alone should close any theory of the power amp.
 

An92

Senior Member
Oct 29, 2013
141
8
Ok, sure ... Thanks for the information, an information .. Is there a way to understand an original amplifier chip from a fake one?
 

An92

Senior Member
Oct 29, 2013
141
8
Do you have any suggestions on how to disconnect the original amplifier without damaging the card ?? Unsoldering all the PINs together seems difficult, I have a manual soldering iron available
 

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  • 3
    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