Kwen said:

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.

millab said:

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

Click to expand...

Do you know if i change the Mosfet and solder a new PA2030A, the RCA sound will improve? Or this chip only affects the direct speaker output.

angelparras said:

Do you know if i change the Mosfet and solder a new PA2030A, the RCA sound will improve? Or this chip only affects the direct speaker output.

Read forums. Improvements are placebo effect.

Add external amplifier and be happy

marchnz said:

Read forums. Improvements are placebo effect.

Add external amplifier and be happy

I have installed this equipment and i am having background noise:

Alpine - R-A60F Amplificador de Potencia de 4 Canales de la Serie-R Potencia RMS 4 x 150W @ 2 Ohms - Potencia Máxima Total: 1200W

Alpine - R-A60F Amplificador de Potencia de 4 Canales de la Serie-R Potencia RMS 4 x 150W @ 2 Ohms - Potencia Máxima Total: 1200W

www.alpine.es

Alpine - S-S65C Altavoz Componente 2 Vías Serie S 6-1/2

Alpine - S-S65C Altavoz Componente 2 Vías Serie S 6-1/2" (16.5 cm)

www.alpine.es

Alpine - S-S65 Altavoz Coaxial 2 Vías Serie S 6-1/2

Alpine - S-S65 Altavoz Coaxial 2 Vías Serie S 6-1/2" (16.5 cm)

www.alpine.es

angelparras said:

I have installed this equipment and i am having background noise:

Alpine - R-A60F Amplificador de Potencia de 4 Canales de la Serie-R Potencia RMS 4 x 150W @ 2 Ohms - Potencia Máxima Total: 1200W

Alpine - R-A60F Amplificador de Potencia de 4 Canales de la Serie-R Potencia RMS 4 x 150W @ 2 Ohms - Potencia Máxima Total: 1200W

www.alpine.es

Alpine - S-S65C Altavoz Componente 2 Vías Serie S 6-1/2

Alpine - S-S65C Altavoz Componente 2 Vías Serie S 6-1/2" (16.5 cm)

www.alpine.es

Alpine - S-S65 Altavoz Coaxial 2 Vías Serie S 6-1/2

Alpine - S-S65 Altavoz Coaxial 2 Vías Serie S 6-1/2" (16.5 cm)

www.alpine.es

Thats why i was asking if i can do any upgrade on my unit to help improve the noise.

Click to expand...

Yep, known issue with these cheap Chinese origin units. Have a scan through forums.

Consider replacing with optical out unit.

marchnz said:

Yep, known issue with these cheap Chinese origin units. Have a scan through forums.

Consider replacing with optical out unit.

You mean replacing the entire head unit?

angelparras said:

You mean replacing the entire head unit?

It isn't necessarily a known issue with all Chinese Head units mine, (Xtrons/GS, PX5/Oreo 8, 4/32 of 2018 vintage) in my Audi A4 B7, non-bose, has never had hum or interference, from day one, and I work professionally with audio/video equipment and production, so I would certainly recognise it. Hum or background noise is most always a grounding issue and often impedance mismatching to aftermarket amps/ speakers such as you have. Whilst these head units are in no way of the highest quality construction, and their shielding can often be very sub-par, that would show itself after DAC and within the analogue section, which could be somewhat alleviated by certain modifications.

I agree totally however, that changing the amp chip, would not be one of them and is an unnecessary placebo.