Do this works to clean the dity audio on this unit? What is the benefit on changing the amplifier chip?
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
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)
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.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.
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/
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.
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.
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
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
Friends, I changed the sound integrated circuit, there was no change in the sound. Now I have another problem. After working for 10 minutes, the music constantly cuts out when the volume is high. When I turn the volume down it goes back to normal. Do I need to change the capacitor? I wonder if the power is not enough? I'm waiting for your help. Kind regards.
I didn't quite understand. Could you elaborate on the subject a little? If I change the capacitor and give more power to the sound chip, will it be fixed? 10000 uf is like 25 waat. Because when I turn up the volume or play bassy music, the sound cuts out. There was no such problem with the previous sound chip. I plugged this Pioneer PA2030 into it and the problems started.
Marchnz suffered, so we might avoid, years ago, changing all this stuff on the PX5s - and time and time again, the message he has outlined, been clear - nothing whatsoever to be gained!Ps. There is little to gain from replacing the power amp IC, fit an external for meaningful performance improvement. Endorsements from users replacing the IC for "upgrade" is placebo affect/cognitive bias. So says the Power amp IC spec sheets.
Yeah, because if you see something on a Russian forum, you absolutely must do!!!!Hi everyone, I came across a mod on a russian forum and decided to give it a try myself.
So here is the problem with what you did.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.